[Rework] Use another version of hash table from the same author

24 files changed, 2281 insertions, 2513 deletions

diff --git a/contrib/DEPENDENCY_INFO.md b/contrib/DEPENDENCY_INFO.md
index fd01fa5ae..9c5cdb431 100644
--- a/contrib/DEPENDENCY_INFO.md
+++ b/contrib/DEPENDENCY_INFO.md
@@ -1,38 +1,39 @@
 # Rspamd Dependency Info
 
-| Name          | Version | License             | Patched | Notes              |
-| ---           |---------| ---                 | ---     | ---                |
-| aho-corasick  | ?       | LGPL-3.0            | YES     | lowercase support  |
-| cdb           | 1.1.0   | Public Domain / CC0 | NO      |                    |
-| hiredis       | 0.13.3  | BSD-3-Clause        | YES     | many changes       |
-| libev         | 4.33    | BSD-2-Clause        | YES     | many changes       |
-| lc-btrie      | ?       | BSD-3-Clause        | YES     | mempool support    |
-| libottery     | ?       | Public Domain / CC0 | YES     | many changes       |
-| librdns       | ?       | BSD-2-Clause        | YES     |                    |
-| libucl        | ?       | BSD-2-Clause        | YES     |                    |
-| replxx        | 6d93360 | BSD-2-Clause       | YES     | libicu usage       |
-| lua-argparse  | 0.7.1   | MIT                 | NO      |                    |
-| lua-bit       | 1.0.2   | MIT                 | YES     | build fixes        |
-| lua-fun       | ?       | MIT                 | YES     | rspamd text        |
-| lua-lpeg      | 1.0     | MIT                 | YES     | rspamd text + alloc|
-| lua-moses     | ?       | MIT                 | NO      |                    |
-| lua-lupa      | ?       | MIT                 | NO      |                    |
-| lua-tableshape | ae67256 | MIT                | NO      |                    |
-| mumhash       | ?       | MIT                 | NO      |                    |
-| ngx-http-parser | 2.2.0   | MIT                 | YES     | spamc support      |
-| Mozilla-PublicSuffix | ?       | MIT                | NO      |                    |
-| snowball      | ?       | BSD-3-Clause        | NO      |                    |
-| t1ha          | ?       | Zlib                | NO      |                    |
-| uthash        | 1.9.8   | BSD                 | YES     |                    |
-| xxhash        | 0.8.1   | BSD                 | NO      |                    |
-| zstd          | 1.4.5   | BSD                 | NO      |                    |
-| google-ced    | 37529e6 | Apache 2            | YES     | build fixes        |
-| kann          | ?       | MIT                 | YES     | blas/lapack changes|
-| fpconv        | ?       | Boost               | YES     | many changes       |
-| fastutf8      | ?       | MIT                 | YES     | many changes       |
-| expected      | v1.0    | Public Domain / CC0 | NO      |                    |
-| robin-hood    | 3.9.1   | MIT                 | NO      |                    |
-| frozen        | 1.0.1   | Apache 2            | NO      |                    |
-| fmt           | 8.1.1   | MIT                 | NO      |                    |
-| doctest       | 2.4.6   | MIT                 | NO      |                    |
-| function2     | 4.1.0   | Boost               | NO      |                    |
+| Name                   | Version | License             | Patched | Notes              |
+|------------------------|---------|---------------------| ---     | ---                |
+| aho-corasick           | ?       | LGPL-3.0            | YES     | lowercase support  |
+| cdb                    | 1.1.0   | Public Domain / CC0 | NO      |                    |
+| hiredis                | 0.13.3  | BSD-3-Clause        | YES     | many changes       |
+| libev                  | 4.33    | BSD-2-Clause        | YES     | many changes       |
+| lc-btrie               | ?       | BSD-3-Clause        | YES     | mempool support    |
+| libottery              | ?       | Public Domain / CC0 | YES     | many changes       |
+| librdns                | ?       | BSD-2-Clause        | YES     |                    |
+| libucl                 | ?       | BSD-2-Clause        | YES     |                    |
+| replxx                 | 6d93360 | BSD-2-Clause        | YES     | libicu usage       |
+| lua-argparse           | 0.7.1   | MIT                 | NO      |                    |
+| lua-bit                | 1.0.2   | MIT                 | YES     | build fixes        |
+| lua-fun                | ?       | MIT                 | YES     | rspamd text        |
+| lua-lpeg               | 1.0     | MIT                 | YES     | rspamd text + alloc|
+| lua-moses              | ?       | MIT                 | NO      |                    |
+| lua-lupa               | ?       | MIT                 | NO      |                    |
+| lua-tableshape         | ae67256 | MIT                 | NO      |                    |
+| mumhash                | ?       | MIT                 | NO      |                    |
+| ngx-http-parser        | 2.2.0   | MIT                 | YES     | spamc support      |
+| Mozilla-PublicSuffix   | ?       | MIT                 | NO      |                    |
+| snowball               | ?       | BSD-3-Clause        | NO      |                    |
+| t1ha                   | ?       | Zlib                | NO      |                    |
+| uthash                 | 1.9.8   | BSD                 | YES     |                    |
+| xxhash                 | 0.8.1   | BSD                 | NO      |                    |
+| zstd                   | 1.4.5   | BSD                 | NO      |                    |
+| google-ced             | 37529e6 | Apache 2            | YES     | build fixes        |
+| kann                   | ?       | MIT                 | YES     | blas/lapack changes|
+| fpconv                 | ?       | Boost               | YES     | many changes       |
+| fastutf8               | ?       | MIT                 | YES     | many changes       |
+| expected               | v1.0    | Public Domain / CC0 | NO      |                    |
+| frozen                 | 1.0.1   | Apache 2            | NO      |                    |
+| fmt                    | 8.1.1   | MIT                 | NO      |                    |
+| doctest                | 2.4.6   | MIT                 | NO      |                    |
+| function2              | 4.1.0   | Boost               | NO      |                    |
+| ankerl/svector         | 1.0.0   | MIT                 | NO      |                    |
+| ankerl/unordered_dense | 1.0.2   | MIT                 | NO      |                    |
\ No newline at end of file
diff --git a/contrib/robin-hood/LICENSE b/contrib/ankerl/LICENSE
index e9a58ad65..c4d1a0e48 100644
--- a/contrib/robin-hood/LICENSE
+++ b/contrib/ankerl/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2018-2019 Martin Ankerl
+Copyright (c) 2022 Martin Leitner-Ankerl
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/contrib/ankerl/svector.h b/contrib/ankerl/svector.h
new file mode 100644
index 000000000..b6ef1ad68
--- /dev/null
+++ b/contrib/ankerl/svector.h
@@ -0,0 +1,993 @@
+// ┌─┐┬  ┬┌─┐┌─┐┌┬┐┌─┐┬─┐   Compact SVO optimized vector C++17 or higher
+// └─┐└┐┌┘├┤ │   │ │ │├┬┘   Version 1.0.0
+// └─┘ └┘ └─┘└─┘ ┴ └─┘┴└─   https://github.com/martinus/svector
+//
+// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022 Martin Leitner-Ankerl <martin.ankerl@gmail.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#ifndef ANKERL_SVECTOR_H
+#define ANKERL_SVECTOR_H
+
+// see https://semver.org/spec/v2.0.0.html
+#define ANKERL_SVECTOR_VERSION_MAJOR 1 // incompatible API changes
+#define ANKERL_SVECTOR_VERSION_MINOR 0 // add functionality in a backwards compatible manner
+#define ANKERL_SVECTOR_VERSION_PATCH 0 // backwards compatible bug fixes
+
+// API versioning with inline namespace, see https://www.foonathan.net/2018/11/inline-namespaces/
+#define ANKERL_SVECTOR_VERSION_CONCAT1(major, minor, patch) v##major##_##minor##_##patch
+#define ANKERL_SVECTOR_VERSION_CONCAT(major, minor, patch) ANKERL_SVECTOR_VERSION_CONCAT1(major, minor, patch)
+#define ANKERL_SVECTOR_NAMESPACE \
+    ANKERL_SVECTOR_VERSION_CONCAT(ANKERL_SVECTOR_VERSION_MAJOR, ANKERL_SVECTOR_VERSION_MINOR, ANKERL_SVECTOR_VERSION_PATCH)
+
+#include <algorithm>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <initializer_list>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <new>
+#include <stdexcept>
+#include <type_traits>
+#include <utility>
+
+namespace ankerl {
+inline namespace ANKERL_SVECTOR_NAMESPACE {
+namespace detail {
+
+template <typename Condition, typename T = void>
+using enable_if_t = typename std::enable_if<Condition::value, T>::type;
+
+template <typename It>
+using is_input_iterator = std::is_base_of<std::input_iterator_tag, typename std::iterator_traits<It>::iterator_category>;
+
+constexpr auto round_up(size_t n, size_t multiple) -> size_t {
+    return ((n + (multiple - 1)) / multiple) * multiple;
+}
+
+template <typename T>
+constexpr auto cx_min(T a, T b) -> T {
+    return a < b ? a : b;
+}
+
+template <typename T>
+constexpr auto cx_max(T a, T b) -> T {
+    return a > b ? a : b;
+}
+
+template <typename T>
+constexpr auto alignment_of_svector() -> size_t {
+    return cx_max(sizeof(void*), std::alignment_of_v<T>);
+}
+
+/**
+ * @brief Calculates sizeof(svector<T, N>) for a given type and inline capacity
+ */
+template <typename T>
+constexpr auto size_of_svector(size_t min_inline_capacity) -> size_t {
+    // + 1 for one byte size in direct mode
+    return round_up(sizeof(T) * min_inline_capacity + 1, alignment_of_svector<T>());
+}
+
+/**
+ * @brief Calculates how many T we can actually store inside of an svector without increasing its sizeof().
+ *
+ * E.g. svector<char, 1> could store 7 bytes even though 1 is specified. This makes sure we don't waste any
+ * of the padding.
+ */
+template <typename T>
+constexpr auto automatic_capacity(size_t min_inline_capacity) -> size_t {
+    return cx_min((size_of_svector<T>(min_inline_capacity) - 1U) / sizeof(T), size_t(127));
+}
+
+/**
+ * Holds size & capacity, a glorified struct.
+ */
+class header {
+    size_t m_size{};
+    size_t const m_capacity;
+
+public:
+    inline explicit header(size_t capacity)
+        : m_capacity{capacity} {}
+
+    [[nodiscard]] inline auto size() const -> size_t {
+        return m_size;
+    }
+
+    [[nodiscard]] inline auto capacity() const -> size_t {
+        return m_capacity;
+    }
+
+    inline void size(size_t s) {
+        m_size = s;
+    }
+};
+
+/**
+ * @brief Holds header (size+capacity) plus an arbitrary number of T.
+ *
+ * To make storage compact, we don't actually store a pointer to T. We don't have to
+ * because we know exactly at which location it begins.
+ */
+template <typename T>
+struct storage : public header {
+    static constexpr auto alignment_of_t = std::alignment_of_v<T>;
+    static constexpr auto max_alignment = std::max(std::alignment_of_v<header>, std::alignment_of_v<T>);
+    static constexpr auto offset_to_data = detail::round_up(sizeof(header), alignment_of_t);
+    static_assert(max_alignment <= __STDCPP_DEFAULT_NEW_ALIGNMENT__);
+
+    explicit storage(size_t capacity)
+        : header(capacity) {}
+
+    auto data() -> T* {
+        auto ptr_to_data = reinterpret_cast<std::byte*>(this) + offset_to_data;
+        return std::launder(reinterpret_cast<T*>(ptr_to_data));
+    }
+
+    /**
+     * @brief Allocates space for storage plus capacity*T objects.
+     *
+     * Checks to make sure that allocation won't overflow.
+     *
+     * @param capacity Number of T to allocate.
+     * @return storage<T>*
+     */
+    static auto alloc(size_t capacity) -> storage<T>* {
+        // make sure we don't overflow!
+        auto mem = sizeof(T) * capacity;
+        if (mem < capacity) {
+            throw std::bad_alloc();
+        }
+        if (offset_to_data + mem < mem) {
+            throw std::bad_alloc();
+        }
+        mem += offset_to_data;
+        if (static_cast<uint64_t>(mem) > static_cast<uint64_t>(std::numeric_limits<std::ptrdiff_t>::max())) {
+            throw std::bad_alloc();
+        }
+
+        void* ptr = ::operator new(offset_to_data + sizeof(T) * capacity);
+        if (nullptr == ptr) {
+            throw std::bad_alloc();
+        }
+        // use void* to ensure we don't use an overload for T*
+        return new (ptr) storage<T>(capacity);
+    }
+};
+
+} // namespace detail
+
+template <typename T, size_t MinInlineCapacity>
+class svector {
+    static_assert(MinInlineCapacity <= 127, "sorry, can't have more than 127 direct elements");
+    static constexpr auto N = detail::automatic_capacity<T>(MinInlineCapacity);
+
+    enum class direction { direct, indirect };
+
+    /**
+     * A buffer to hold the data of the svector Depending on direct/indirect mode, the content it holds is like so:
+     *
+     * direct:
+     *    m_data[0] & 1: lowest bit is 1 for direct mode.
+     *    m_data[0] >> 1: size for direct mode
+     *    Then 0-X bytes unused (padding), and then the actual inline T data.
+     * indirect:
+     *    m_data[0] & 1: lowest bit is 0 for indirect mode
+     *    m_data[0..7]: stores an uintptr_t, which points to the indirect data.
+     */
+    alignas(detail::alignment_of_svector<T>()) std::array<uint8_t, detail::size_of_svector<T>(MinInlineCapacity)> m_data;
+
+    // direct mode ///////////////////////////////////////////////////////////
+
+    [[nodiscard]] auto is_direct() const -> bool {
+        return (m_data[0] & 1U) != 0U;
+    }
+
+    [[nodiscard]] auto direct_size() const -> size_t {
+        return m_data[0] >> 1U;
+    }
+
+    // sets size of direct mode and mode to direct too.
+    constexpr void set_direct_and_size(size_t s) {
+        m_data[0] = (s << 1U) | 1U;
+    }
+
+    [[nodiscard]] auto direct_data() -> T* {
+        return std::launder(reinterpret_cast<T*>(m_data.data() + std::alignment_of_v<T>));
+    }
+
+    // indirect mode /////////////////////////////////////////////////////////
+
+    [[nodiscard]] auto indirect() -> detail::storage<T>* {
+        detail::storage<T>* ptr; // NOLINT(cppcoreguidelines-init-variables)
+        std::memcpy(&ptr, m_data.data(), sizeof(ptr));
+        return ptr;
+    }
+
+    [[nodiscard]] auto indirect() const -> detail::storage<T> const* {
+        return const_cast<svector*>(this)->indirect(); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    void set_indirect(detail::storage<T>* ptr) {
+        std::memcpy(m_data.data(), &ptr, sizeof(ptr));
+
+        // safety check to guarantee the lowest bit is 0
+        if (is_direct()) {
+            throw std::bad_alloc(); // LCOV_EXCL_LINE
+        }
+    }
+
+    // helpers ///////////////////////////////////////////////////////////////
+
+    /**
+     * @brief Moves size objects from source_ptr to target_ptr, and destroys what remains in source_ptr.
+     *
+     * Assumes data is not overlapping
+     */
+    static void uninitialized_move_and_destroy(T* source_ptr, T* target_ptr, size_t size) {
+        if constexpr (std::is_trivially_copyable_v<T>) {
+            std::memcpy(target_ptr, source_ptr, size * sizeof(T));
+        } else {
+            std::uninitialized_move_n(source_ptr, size, target_ptr);
+            std::destroy_n(source_ptr, size);
+        }
+    }
+
+    /**
+     * @brief Reallocates all data when capacity changes.
+     *
+     * if new_capacity <= N chooses direct memory, otherwise indirect.
+     */
+    void realloc(size_t new_capacity) {
+        if (new_capacity <= N) {
+            // put everything into direct storage
+            if (is_direct()) {
+                // direct -> direct: nothing to do!
+                return;
+            }
+
+            // indirect -> direct
+            auto* storage = indirect();
+            uninitialized_move_and_destroy(storage->data(), direct_data(), storage->size());
+            set_direct_and_size(storage->size());
+            delete storage;
+        } else {
+            // put everything into indirect storage
+            auto* storage = detail::storage<T>::alloc(new_capacity);
+            if (is_direct()) {
+                // direct -> indirect
+                uninitialized_move_and_destroy(data<direction::direct>(), storage->data(), size<direction::direct>());
+                storage->size(size<direction::direct>());
+            } else {
+                // indirect -> indirect
+                uninitialized_move_and_destroy(data<direction::indirect>(), storage->data(), size<direction::indirect>());
+                storage->size(size<direction::indirect>());
+                delete indirect();
+            }
+            set_indirect(storage);
+        }
+    }
+
+    /**
+     * @brief Doubles starting_capacity until it is >= size_to_fit.
+     */
+    [[nodiscard]] static auto calculate_new_capacity(size_t size_to_fit, size_t starting_capacity) -> size_t {
+        if (size_to_fit > max_size()) {
+            // not enough space
+            throw std::bad_alloc();
+        }
+
+        if (size_to_fit == 0) {
+            // special handling for 0 so N==0 works
+            return starting_capacity;
+        }
+        // start with at least 1, so N==0 works
+        auto new_capacity = std::max<size_t>(1, starting_capacity);
+
+        // double capacity until its large enough, but make sure we don't overflow
+        while (new_capacity < size_to_fit && new_capacity * 2 > new_capacity) {
+            new_capacity *= 2;
+        }
+        if (new_capacity < size_to_fit) {
+            // got an overflow, set capacity to max
+            new_capacity = max_size();
+        }
+        return std::min(new_capacity, max_size());
+    }
+
+    template <direction D>
+    [[nodiscard]] auto capacity() const -> size_t {
+        if constexpr (D == direction::direct) {
+            return N;
+        } else {
+            return indirect()->capacity();
+        }
+    }
+
+    template <direction D>
+    [[nodiscard]] auto size() const -> size_t {
+        if constexpr (D == direction::direct) {
+            return direct_size();
+        } else {
+            return indirect()->size();
+        }
+    }
+
+    template <direction D>
+    void set_size(size_t s) {
+        if constexpr (D == direction::direct) {
+            set_direct_and_size(s);
+        } else {
+            indirect()->size(s);
+        }
+    }
+
+    void set_size(size_t s) {
+        if (is_direct()) {
+            set_size<direction::direct>(s);
+        } else {
+            set_size<direction::indirect>(s);
+        }
+    }
+
+    template <direction D>
+    [[nodiscard]] auto data() -> T* {
+        if constexpr (D == direction::direct) {
+            return direct_data();
+        } else {
+            return indirect()->data();
+        }
+    }
+
+    template <direction D>
+    [[nodiscard]] auto data() const -> T const* {
+        return const_cast<svector*>(this)->data<D>(); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    template <direction D>
+    void pop_back() {
+        if constexpr (std::is_trivially_destructible_v<T>) {
+            set_size<D>(size<D>() - 1);
+        } else {
+            auto s = size<D>() - 1;
+            (data<D>() + s)->~T();
+            set_size<D>(s);
+        }
+    }
+
+    /**
+     * @brief We need variadic arguments so we can either use copy ctor or default ctor
+     */
+    template <direction D, class... Args>
+    void resize_after_reserve(size_t count, Args&&... args) {
+        auto current_size = size<D>();
+        if (current_size > count) {
+            if constexpr (!std::is_trivially_destructible_v<T>) {
+                auto* d = data<D>();
+                std::destroy(d + count, d + current_size);
+            }
+        } else {
+            auto* d = data<D>();
+            for (auto ptr = d + current_size, end = d + count; ptr != end; ++ptr) {
+                new (static_cast<void*>(ptr)) T(std::forward<Args>(args)...);
+            }
+        }
+        set_size<D>(count);
+    }
+
+    // Makes sure that to is not past the end iterator
+    template <direction D>
+    auto erase_checked_end(T const* cfrom, T const* to) -> T* {
+        auto* const erase_begin = const_cast<T*>(cfrom); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+        auto* const container_end = data<D>() + size<D>();
+        auto* const erase_end = std::min(const_cast<T*>(to), container_end); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+
+        std::move(erase_end, container_end, erase_begin);
+        auto const num_erased = std::distance(erase_begin, erase_end);
+        std::destroy(container_end - num_erased, container_end);
+        set_size<D>(size<D>() - num_erased);
+        return erase_begin;
+    }
+
+    template <typename It>
+    void assign(It first, It last, std::input_iterator_tag /*unused*/) {
+        clear();
+
+        // TODO this can be made faster, e.g. by setting size only when finished.
+        while (first != last) {
+            push_back(*first);
+            ++first;
+        }
+    }
+
+    template <typename It>
+    void assign(It first, It last, std::forward_iterator_tag /*unused*/) {
+        clear();
+
+        auto s = std::distance(first, last);
+        reserve(s);
+        std::uninitialized_copy(first, last, data());
+        set_size(s);
+    }
+
+    // precondition: all uninitialized
+    void do_move_assign(svector&& other) {
+        if (!other.is_direct()) {
+            // take other's memory, even when empty
+            set_indirect(other.indirect());
+        } else {
+            auto* other_ptr = other.data<direction::direct>();
+            auto s = other.size<direction::direct>();
+            auto* other_end = other_ptr + s;
+
+            std::uninitialized_move(other_ptr, other_end, data<direction::direct>());
+            std::destroy(other_ptr, other_end);
+            set_size(s);
+        }
+        other.set_direct_and_size(0);
+    }
+
+    /**
+     * @brief Shifts data [source_begin, source_end( to the right, starting on target_begin.
+     *
+     * Preconditions:
+     * * contiguous memory
+     * * source_begin <= target_begin
+     * * source_end onwards is uninitialized memory
+     *
+     * Destroys then empty elements in [source_begin, source_end(
+     */
+    static auto shift_right(T* source_begin, T* source_end, T* target_begin) {
+        // 1. uninitialized moves
+        auto const num_moves = std::distance(source_begin, source_end);
+        auto const target_end = target_begin + num_moves;
+        auto const num_uninitialized_move = std::min(num_moves, std::distance(source_end, target_end));
+        std::uninitialized_move(source_end - num_uninitialized_move, source_end, target_end - num_uninitialized_move);
+        std::move_backward(source_begin, source_end - num_uninitialized_move, target_end - num_uninitialized_move);
+        std::destroy(source_begin, std::min(source_end, target_begin));
+    }
+
+    template <direction D>
+    [[nodiscard]] auto make_uninitialized_space_new(size_t s, T* p, size_t count) -> T* {
+        auto target = svector();
+        // we know target is indirect because we're increasing capacity
+        target.reserve(s + count);
+
+        // move everything [begin, pos[
+        auto* target_pos = std::uninitialized_move(data<D>(), p, target.template data<direction::indirect>());
+
+        // move everything [pos, end]
+        std::uninitialized_move(p, data<D>() + s, target_pos + count);
+
+        target.template set_size<direction::indirect>(s + count);
+        *this = std::move(target);
+        return target_pos;
+    }
+
+    template <direction D>
+    [[nodiscard]] auto make_uninitialized_space(T const* pos, size_t count) -> T* {
+        auto* const p = const_cast<T*>(pos); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+        auto s = size<D>();
+        if (s + count > capacity<D>()) {
+            return make_uninitialized_space_new<D>(s, p, count);
+        }
+
+        shift_right(p, data<D>() + s, p + count);
+        set_size<D>(s + count);
+        return p;
+    }
+
+    // makes space for uninitialized data of cout elements. Also updates size.
+    [[nodiscard]] auto make_uninitialized_space(T const* pos, size_t count) -> T* {
+        if (is_direct()) {
+            return make_uninitialized_space<direction::direct>(pos, count);
+        }
+        return make_uninitialized_space<direction::indirect>(pos, count);
+    }
+
+    void destroy() {
+        auto const is_dir = is_direct();
+        if constexpr (!std::is_trivially_destructible_v<T>) {
+            T* ptr = nullptr;
+            size_t s = 0;
+            if (is_dir) {
+                ptr = data<direction::direct>();
+                s = size<direction::direct>();
+            } else {
+                ptr = data<direction::indirect>();
+                s = size<direction::indirect>();
+            }
+            std::destroy_n(ptr, s);
+        }
+        if (!is_dir) {
+            delete indirect();
+        }
+    }
+
+    // performs a const_cast so we don't need this implementation twice
+    template <direction D>
+    auto at(size_t idx) -> T& {
+        if (idx >= size<D>()) {
+            throw std::out_of_range{"svector: idx out of range"};
+        }
+        auto* ptr = const_cast<T*>(data<D>() + idx); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+        return *ptr;
+    } // LCOV_EXCL_LINE why is this single } marked as not covered? gcov bug?
+
+public:
+    using value_type = T;
+    using size_type = size_t;
+    using difference_type = std::ptrdiff_t;
+    using reference = value_type&;
+    using const_reference = value_type const&;
+    using pointer = T*;
+    using const_pointer = T const*;
+    using iterator = T*;
+    using const_iterator = T const*;
+    using reverse_iterator = std::reverse_iterator<iterator>;
+    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+
+    svector() {
+        set_direct_and_size(0);
+    }
+
+    svector(size_t count, T const& value)
+        : svector() {
+        resize(count, value);
+    }
+
+    explicit svector(size_t count)
+        : svector() {
+        reserve(count);
+        if (is_direct()) {
+            resize_after_reserve<direction::direct>(count);
+        } else {
+            resize_after_reserve<direction::indirect>(count);
+        }
+    }
+
+    template <typename InputIt, typename = detail::enable_if_t<detail::is_input_iterator<InputIt>>>
+    svector(InputIt first, InputIt last)
+        : svector() {
+        assign(first, last);
+    }
+
+    svector(svector const& other)
+        : svector() {
+        auto s = other.size();
+        reserve(s);
+        std::uninitialized_copy(other.begin(), other.end(), begin());
+        set_size(s);
+    }
+
+    svector(svector&& other) noexcept
+        : svector() {
+        do_move_assign(std::move(other));
+    }
+
+    svector(std::initializer_list<T> init)
+        : svector(init.begin(), init.end()) {}
+
+    ~svector() {
+        destroy();
+    }
+
+    void assign(size_t count, T const& value) {
+        clear();
+        resize(count, value);
+    }
+
+    template <typename InputIt, typename = detail::enable_if_t<detail::is_input_iterator<InputIt>>>
+    void assign(InputIt first, InputIt last) {
+        assign(first, last, typename std::iterator_traits<InputIt>::iterator_category());
+    }
+
+    void assign(std::initializer_list<T> l) {
+        assign(l.begin(), l.end());
+    }
+
+    auto operator=(svector const& other) -> svector& {
+        if (&other == this) {
+            return *this;
+        }
+
+        assign(other.begin(), other.end());
+        return *this;
+    }
+
+    auto operator=(svector&& other) noexcept -> svector& {
+        if (&other == this) {
+            // It doesn't seem to be required to do self-check, but let's do it anyways to be safe
+            return *this;
+        }
+        destroy();
+        do_move_assign(std::move(other));
+        return *this;
+    }
+
+    auto operator=(std::initializer_list<T> l) -> svector& {
+        assign(l.begin(), l.end());
+        return *this;
+    }
+
+    void resize(size_t count) {
+        if (count > capacity()) {
+            reserve(count);
+        }
+        if (is_direct()) {
+            resize_after_reserve<direction::direct>(count);
+        } else {
+            resize_after_reserve<direction::indirect>(count);
+        }
+    }
+
+    void resize(size_t count, T const& value) {
+        if (count > capacity()) {
+            reserve(count);
+        }
+        if (is_direct()) {
+            resize_after_reserve<direction::direct>(count, value);
+        } else {
+            resize_after_reserve<direction::indirect>(count, value);
+        }
+    }
+
+    auto reserve(size_t s) {
+        auto old_capacity = capacity();
+        auto new_capacity = calculate_new_capacity(s, old_capacity);
+        if (new_capacity > old_capacity) {
+            realloc(new_capacity);
+        }
+    }
+
+    [[nodiscard]] auto capacity() const -> size_t {
+        if (is_direct()) {
+            return capacity<direction::direct>();
+        }
+        return capacity<direction::indirect>();
+    }
+
+    [[nodiscard]] auto size() const -> size_t {
+        if (is_direct()) {
+            return size<direction::direct>();
+        }
+        return size<direction::indirect>();
+    }
+
+    [[nodiscard]] auto data() -> T* {
+        if (is_direct()) {
+            return direct_data();
+        }
+        return indirect()->data();
+    }
+
+    [[nodiscard]] auto data() const -> T const* {
+        return const_cast<svector*>(this)->data(); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    template <class... Args>
+    auto emplace_back(Args&&... args) -> T& {
+        size_t c; // NOLINT(cppcoreguidelines-init-variables)
+        size_t s; // NOLINT(cppcoreguidelines-init-variables)
+        bool is_dir = is_direct();
+        if (is_dir) {
+            c = capacity<direction::direct>();
+            s = size<direction::direct>();
+        } else {
+            c = capacity<direction::indirect>();
+            s = size<direction::indirect>();
+        }
+
+        if (s == c) {
+            auto new_capacity = calculate_new_capacity(s + 1, c);
+            realloc(new_capacity);
+            // reallocation happened, so we definitely are now in indirect mode
+            is_dir = false;
+        }
+
+        T* ptr; // NOLINT(cppcoreguidelines-init-variables)
+        if (is_dir) {
+            ptr = data<direction::direct>() + s;
+            set_size<direction::direct>(s + 1);
+        } else {
+            ptr = data<direction::indirect>() + s;
+            set_size<direction::indirect>(s + 1);
+        }
+        return *new (static_cast<void*>(ptr)) T(std::forward<Args>(args)...);
+    }
+
+    void push_back(T const& value) {
+        emplace_back(value);
+    }
+
+    void push_back(T&& value) {
+        emplace_back(std::move(value));
+    }
+
+    [[nodiscard]] auto operator[](size_t idx) const -> T const& {
+        return *(data() + idx);
+    }
+
+    [[nodiscard]] auto operator[](size_t idx) -> T& {
+        return *(data() + idx);
+    }
+
+    auto at(size_t idx) -> T& {
+        if (is_direct()) {
+            return at<direction::direct>(idx);
+        }
+        return at<direction::indirect>(idx);
+    }
+
+    auto at(size_t idx) const -> T const& {
+        return const_cast<svector*>(this)->at(idx); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    [[nodiscard]] auto begin() const -> T const* {
+        return data();
+    }
+
+    [[nodiscard]] auto cbegin() const -> T const* {
+        return begin();
+    }
+
+    [[nodiscard]] auto begin() -> T* {
+        return data();
+    }
+
+    [[nodiscard]] auto end() -> T* {
+        if (is_direct()) {
+            return data<direction::direct>() + size<direction::direct>();
+        }
+        return data<direction::indirect>() + size<direction::indirect>();
+    }
+
+    [[nodiscard]] auto end() const -> T const* {
+        return const_cast<svector*>(this)->end(); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    [[nodiscard]] auto cend() const -> T const* {
+        return end();
+    }
+
+    [[nodiscard]] auto rbegin() -> reverse_iterator {
+        return reverse_iterator{end()};
+    }
+
+    [[nodiscard]] auto rbegin() const -> const_reverse_iterator {
+        return crbegin();
+    }
+
+    [[nodiscard]] auto crbegin() const -> const_reverse_iterator {
+        return const_reverse_iterator{end()};
+    }
+
+    [[nodiscard]] auto rend() -> reverse_iterator {
+        return reverse_iterator{begin()};
+    }
+
+    [[nodiscard]] auto rend() const -> const_reverse_iterator {
+        return crend();
+    }
+
+    [[nodiscard]] auto crend() const -> const_reverse_iterator {
+        return const_reverse_iterator{begin()};
+    }
+
+    [[nodiscard]] auto front() const -> T const& {
+        return *data();
+    }
+
+    [[nodiscard]] auto front() -> T& {
+        return *data();
+    }
+
+    [[nodiscard]] auto back() -> T& {
+        if (is_direct()) {
+            return *(data<direction::direct>() + size<direction::direct>() - 1);
+        }
+        return *(data<direction::indirect>() + size<direction::indirect>() - 1);
+    }
+
+    [[nodiscard]] auto back() const -> T const& {
+        return const_cast<svector*>(this)->back(); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    void clear() {
+        if constexpr (!std::is_trivially_destructible_v<T>) {
+            std::destroy(begin(), end());
+        }
+
+        if (is_direct()) {
+            set_size<direction::direct>(0);
+        } else {
+            set_size<direction::indirect>(0);
+        }
+    }
+
+    [[nodiscard]] auto empty() const -> bool {
+        return 0U == size();
+    }
+
+    void pop_back() {
+        if (is_direct()) {
+            pop_back<direction::direct>();
+        } else {
+            pop_back<direction::indirect>();
+        }
+    }
+
+    [[nodiscard]] static auto max_size() -> size_t {
+        return std::numeric_limits<std::ptrdiff_t>::max();
+    }
+
+    void swap(svector& other) {
+        // TODO we could try to do the minimum number of moves
+        std::swap(*this, other);
+    }
+
+    void shrink_to_fit() {
+        // per the standard we wouldn't need to do anything here. But since we are so nice,
+        // let's do the shrink.
+        auto const c = capacity();
+        auto const s = size();
+        if (s >= c) {
+            return;
+        }
+
+        auto new_capacity = calculate_new_capacity(s, N);
+        if (new_capacity == c) {
+            // nothing change!
+            return;
+        }
+
+        realloc(new_capacity);
+    }
+
+    template <class... Args>
+    auto emplace(const_iterator pos, Args&&... args) -> iterator {
+        auto* p = make_uninitialized_space(pos, 1);
+        return new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
+    }
+
+    auto insert(const_iterator pos, T const& value) -> iterator {
+        return emplace(pos, value);
+    }
+
+    auto insert(const_iterator pos, T&& value) -> iterator {
+        return emplace(pos, std::move(value));
+    }
+
+    auto insert(const_iterator pos, size_t count, T const& value) -> iterator {
+        auto* p = make_uninitialized_space(pos, count);
+        std::uninitialized_fill_n(p, count, value);
+        return p;
+    }
+
+    template <typename It>
+    auto insert(const_iterator pos, It first, It last, std::input_iterator_tag /*unused*/) {
+        if (!(first != last)) {
+            return const_cast<T*>(pos); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+        }
+
+        // just input_iterator_tag makes this very slow. Let's do the same as the STL.
+        if (pos == end()) {
+            auto s = size();
+            while (first != last) {
+                emplace_back(*first);
+                ++first;
+            }
+            return begin() + s;
+        }
+
+        auto tmp = svector(first, last);
+        return insert(pos, std::make_move_iterator(tmp.begin()), std::make_move_iterator(tmp.end()));
+    }
+
+    template <typename It>
+    auto insert(const_iterator pos, It first, It last, std::forward_iterator_tag /*unused*/) {
+        auto* p = make_uninitialized_space(pos, std::distance(first, last));
+        std::uninitialized_copy(first, last, p);
+        return p;
+    }
+
+    template <typename InputIt, typename = detail::enable_if_t<detail::is_input_iterator<InputIt>>>
+    auto insert(const_iterator pos, InputIt first, InputIt last) -> iterator {
+        return insert(pos, first, last, typename std::iterator_traits<InputIt>::iterator_category());
+    }
+
+    auto insert(const_iterator pos, std::initializer_list<T> l) -> iterator {
+        return insert(pos, l.begin(), l.end());
+    }
+
+    auto erase(const_iterator pos) -> iterator {
+        return erase(pos, pos + 1);
+    }
+
+    auto erase(const_iterator first, const_iterator last) -> iterator {
+        if (is_direct()) {
+            return erase_checked_end<direction::direct>(first, last);
+        }
+        return erase_checked_end<direction::indirect>(first, last);
+    }
+};
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator==(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return std::equal(a.begin(), a.end(), b.begin(), b.end());
+}
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator!=(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return !(a == b);
+}
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator<(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end());
+}
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator>=(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return !(a < b);
+}
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator>(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return std::lexicographical_compare(b.begin(), b.end(), a.begin(), a.end());
+}
+
+template <typename T, size_t NA, size_t NB>
+[[nodiscard]] auto operator<=(svector<T, NA> const& a, svector<T, NB> const& b) -> bool {
+    return !(a > b);
+}
+
+} // namespace ANKERL_SVECTOR_NAMESPACE
+} // namespace ankerl
+
+// NOLINTNEXTLINE(cert-dcl58-cpp)
+namespace std {
+inline namespace ANKERL_SVECTOR_NAMESPACE {
+
+template <class T, size_t N, class U>
+constexpr auto erase(ankerl::svector<T, N>& sv, U const& value) -> typename ankerl::svector<T, N>::size_type {
+    auto* removed_begin = std::remove(sv.begin(), sv.end(), value);
+    auto num_removed = std::distance(removed_begin, sv.end());
+    sv.erase(removed_begin, sv.end());
+    return num_removed;
+}
+
+template <class T, size_t N, class Pred>
+constexpr auto erase_if(ankerl::svector<T, N>& sv, Pred pred) -> typename ankerl::svector<T, N>::size_type {
+    auto* removed_begin = std::remove_if(sv.begin(), sv.end(), pred);
+    auto num_removed = std::distance(removed_begin, sv.end());
+    sv.erase(removed_begin, sv.end());
+    return num_removed;
+}
+
+} // namespace ANKERL_SVECTOR_NAMESPACE
+} // namespace std
+
+#endif
diff --git a/contrib/ankerl/unordered_dense.h b/contrib/ankerl/unordered_dense.h
new file mode 100644
index 000000000..9ae108173
--- /dev/null
+++ b/contrib/ankerl/unordered_dense.h
@@ -0,0 +1,1199 @@
+///////////////////////// ankerl::unordered_dense::{map, set} /////////////////////////
+
+// A fast & densely stored hashmap and hashset based on robin-hood backward shift deletion.
+// Version 1.0.2
+// https://github.com/martinus/unordered_dense
+//
+// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022 Martin Leitner-Ankerl <martin.ankerl@gmail.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#ifndef ANKERL_UNORDERED_DENSE_H
+#define ANKERL_UNORDERED_DENSE_H
+
+// see https://semver.org/spec/v2.0.0.html
+#define ANKERL_UNORDERED_DENSE_VERSION_MAJOR 1 // incompatible API changes
+#define ANKERL_UNORDERED_DENSE_VERSION_MINOR 0 // add functionality in a backwards compatible manner
+#define ANKERL_UNORDERED_DENSE_VERSION_PATCH 2 // backwards compatible bug fixes
+
+#if __cplusplus < 201703L
+#    error ankerl::unordered_dense requires C++17 or higher
+#else
+
+#    include <array>            // for array
+#    include <cstdint>          // for uint64_t, uint32_t, uint8_t, UINT64_C
+#    include <cstring>          // for size_t, memcpy, memset
+#    include <functional>       // for equal_to, hash
+#    include <initializer_list> // for initializer_list
+#    include <iterator>         // for pair, distance
+#    include <limits>           // for numeric_limits
+#    include <memory>           // for allocator, allocator_traits, shared_ptr
+#    include <stdexcept>        // for out_of_range
+#    include <string>           // for basic_string
+#    include <string_view>      // for basic_string_view, hash
+#    include <tuple>            // for forward_as_tuple
+#    include <type_traits>      // for enable_if_t, declval, conditional_t, ena...
+#    include <utility>          // for forward, exchange, pair, as_const, piece...
+#    include <vector>           // for vector
+
+#    define ANKERL_UNORDERED_DENSE_PMR 0
+#    if defined(__has_include)
+#        if __has_include(<memory_resource>)
+#            undef ANKERL_UNORDERED_DENSE_PMR
+#            define ANKERL_UNORDERED_DENSE_PMR 1
+#            include <memory_resource> // for polymorphic_allocator
+#        endif
+#    endif
+
+#    if defined(_MSC_VER) && defined(_M_X64)
+#        include <intrin.h>
+#        pragma intrinsic(_umul128)
+#    endif
+
+#    if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
+#        define ANKERL_UNORDERED_DENSE_LIKELY(x) __builtin_expect(x, 1)
+#        define ANKERL_UNORDERED_DENSE_UNLIKELY(x) __builtin_expect(x, 0)
+#    else
+#        define ANKERL_UNORDERED_DENSE_LIKELY(x) (x)
+#        define ANKERL_UNORDERED_DENSE_UNLIKELY(x) (x)
+#    endif
+
+namespace ankerl::unordered_dense {
+
+// hash ///////////////////////////////////////////////////////////////////////
+
+// This is a stripped-down implementation of wyhash: https://github.com/wangyi-fudan/wyhash
+// No big-endian support (because different values on different machines don't matter),
+// hardcodes seed and the secret, reformattes the code, and clang-tidy fixes.
+namespace detail::wyhash {
+
+static inline void mum(uint64_t* a, uint64_t* b) {
+#    if defined(__SIZEOF_INT128__)
+    __uint128_t r = *a;
+    r *= *b;
+    *a = static_cast<uint64_t>(r);
+    *b = static_cast<uint64_t>(r >> 64U);
+#    elif defined(_MSC_VER) && defined(_M_X64)
+    *a = _umul128(*a, *b, b);
+#    else
+    uint64_t ha = *a >> 32U;
+    uint64_t hb = *b >> 32U;
+    uint64_t la = static_cast<uint32_t>(*a);
+    uint64_t lb = static_cast<uint32_t>(*b);
+    uint64_t hi{};
+    uint64_t lo{};
+    uint64_t rh = ha * hb;
+    uint64_t rm0 = ha * lb;
+    uint64_t rm1 = hb * la;
+    uint64_t rl = la * lb;
+    uint64_t t = rl + (rm0 << 32U);
+    auto c = static_cast<uint64_t>(t < rl);
+    lo = t + (rm1 << 32U);
+    c += static_cast<uint64_t>(lo < t);
+    hi = rh + (rm0 >> 32U) + (rm1 >> 32U) + c;
+    *a = lo;
+    *b = hi;
+#    endif
+}
+
+// multiply and xor mix function, aka MUM
+[[nodiscard]] static inline auto mix(uint64_t a, uint64_t b) -> uint64_t {
+    mum(&a, &b);
+    return a ^ b;
+}
+
+// read functions. WARNING: we don't care about endianness, so results are different on big endian!
+[[nodiscard]] static inline auto r8(const uint8_t* p) -> uint64_t {
+    uint64_t v{};
+    std::memcpy(&v, p, 8);
+    return v;
+}
+
+[[nodiscard]] static inline auto r4(const uint8_t* p) -> uint64_t {
+    uint32_t v{};
+    std::memcpy(&v, p, 4);
+    return v;
+}
+
+// reads 1, 2, or 3 bytes
+[[nodiscard]] static inline auto r3(const uint8_t* p, size_t k) -> uint64_t {
+    return (static_cast<uint64_t>(p[0]) << 16U) | (static_cast<uint64_t>(p[k >> 1U]) << 8U) | p[k - 1];
+}
+
+[[nodiscard]] static inline auto hash(void const* key, size_t len) -> uint64_t {
+    static constexpr auto secret = std::array{UINT64_C(0xa0761d6478bd642f),
+                                              UINT64_C(0xe7037ed1a0b428db),
+                                              UINT64_C(0x8ebc6af09c88c6e3),
+                                              UINT64_C(0x589965cc75374cc3)};
+
+    auto const* p = static_cast<uint8_t const*>(key);
+    uint64_t seed = secret[0];
+    uint64_t a{};
+    uint64_t b{};
+    if (ANKERL_UNORDERED_DENSE_LIKELY(len <= 16)) {
+        if (ANKERL_UNORDERED_DENSE_LIKELY(len >= 4)) {
+            a = (r4(p) << 32U) | r4(p + ((len >> 3U) << 2U));
+            b = (r4(p + len - 4) << 32U) | r4(p + len - 4 - ((len >> 3U) << 2U));
+        } else if (ANKERL_UNORDERED_DENSE_LIKELY(len > 0)) {
+            a = r3(p, len);
+            b = 0;
+        } else {
+            a = 0;
+            b = 0;
+        }
+    } else {
+        size_t i = len;
+        if (ANKERL_UNORDERED_DENSE_UNLIKELY(i > 48)) {
+            uint64_t see1 = seed;
+            uint64_t see2 = seed;
+            do {
+                seed = mix(r8(p) ^ secret[1], r8(p + 8) ^ seed);
+                see1 = mix(r8(p + 16) ^ secret[2], r8(p + 24) ^ see1);
+                see2 = mix(r8(p + 32) ^ secret[3], r8(p + 40) ^ see2);
+                p += 48;
+                i -= 48;
+            } while (ANKERL_UNORDERED_DENSE_LIKELY(i > 48));
+            seed ^= see1 ^ see2;
+        }
+        while (ANKERL_UNORDERED_DENSE_UNLIKELY(i > 16)) {
+            seed = mix(r8(p) ^ secret[1], r8(p + 8) ^ seed);
+            i -= 16;
+            p += 16;
+        }
+        a = r8(p + i - 16);
+        b = r8(p + i - 8);
+    }
+
+    return mix(secret[1] ^ len, mix(a ^ secret[1], b ^ seed));
+}
+
+[[nodiscard]] static inline auto hash(uint64_t x) -> uint64_t {
+    return detail::wyhash::mix(x, UINT64_C(0x9E3779B97F4A7C15));
+}
+
+} // namespace detail::wyhash
+
+template <typename T, typename Enable = void>
+struct hash : public std::hash<T> {
+    using is_avalanching = void;
+    auto operator()(T const& obj) const noexcept(noexcept(std::declval<std::hash<T>>().operator()(std::declval<T const&>())))
+        -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(std::hash<T>::operator()(obj)));
+    }
+};
+
+template <typename CharT>
+struct hash<std::basic_string<CharT>> {
+    using is_avalanching = void;
+    auto operator()(std::basic_string<CharT> const& str) const noexcept -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(str.data(), sizeof(CharT) * str.size()));
+    }
+};
+
+template <typename CharT>
+struct hash<std::basic_string_view<CharT>> {
+    using is_avalanching = void;
+    auto operator()(std::basic_string_view<CharT> const& sv) const noexcept -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(sv.data(), sizeof(CharT) * sv.size()));
+    }
+};
+
+template <class T>
+struct hash<T*> {
+    using is_avalanching = void;
+    auto operator()(T* ptr) const noexcept -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr)));
+    }
+};
+
+template <class T>
+struct hash<std::unique_ptr<T>> {
+    using is_avalanching = void;
+    auto operator()(std::unique_ptr<T> const& ptr) const noexcept -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr.get())));
+    }
+};
+
+template <class T>
+struct hash<std::shared_ptr<T>> {
+    using is_avalanching = void;
+    auto operator()(std::shared_ptr<T> const& ptr) const noexcept -> size_t {
+        return static_cast<size_t>(detail::wyhash::hash(reinterpret_cast<uintptr_t>(ptr.get())));
+    }
+};
+
+template <typename Enum>
+struct hash<Enum, typename std::enable_if<std::is_enum<Enum>::value>::type> {
+    using is_avalanching = void;
+    auto operator()(Enum e) const noexcept -> size_t {
+        using Underlying = typename std::underlying_type_t<Enum>;
+        return static_cast<size_t>(detail::wyhash::hash(static_cast<Underlying>(e)));
+    }
+};
+
+#    define ANKERL_UNORDERED_DENSE_HASH_STATICCAST(T)                                         \
+        template <>                                                                           \
+        struct hash<T> {                                                                      \
+            using is_avalanching = void;                                                      \
+            auto operator()(T const& obj) const noexcept -> size_t {                          \
+                return static_cast<size_t>(detail::wyhash::hash(static_cast<uint64_t>(obj))); \
+            }                                                                                 \
+        }
+
+#    if defined(__GNUC__) && !defined(__clang__)
+#        pragma GCC diagnostic push
+#        pragma GCC diagnostic ignored "-Wuseless-cast"
+#    endif
+// see https://en.cppreference.com/w/cpp/utility/hash
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(bool);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(signed char);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned char);
+#    if __cplusplus >= 202002L
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char8_t);
+#    endif
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char16_t);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(char32_t);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(wchar_t);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(short);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned short);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(int);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned int);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(long);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(long long);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned long);
+ANKERL_UNORDERED_DENSE_HASH_STATICCAST(unsigned long long);
+
+#    if defined(__GNUC__) && !defined(__clang__)
+#        pragma GCC diagnostic pop
+#    endif
+
+namespace detail {
+
+struct nonesuch {};
+
+template <class Default, class AlwaysVoid, template <class...> class Op, class... Args>
+struct detector {
+    using value_t = std::false_type;
+    using type = Default;
+};
+
+template <class Default, template <class...> class Op, class... Args>
+struct detector<Default, std::void_t<Op<Args...>>, Op, Args...> {
+    using value_t = std::true_type;
+    using type = Op<Args...>;
+};
+
+template <template <class...> class Op, class... Args>
+using is_detected = typename detail::detector<detail::nonesuch, void, Op, Args...>::value_t;
+
+template <template <class...> class Op, class... Args>
+constexpr bool is_detected_v = is_detected<Op, Args...>::value;
+
+template <typename T>
+using detect_avalanching = typename T::is_avalanching;
+
+template <typename T>
+using detect_is_transparent = typename T::is_transparent;
+
+template <typename H, typename KE>
+using is_transparent =
+    std::enable_if_t<is_detected_v<detect_is_transparent, H> && is_detected_v<detect_is_transparent, KE>, bool>;
+
+// This is it, the table. Doubles as map and set, and uses `void` for T when its used as a set.
+template <class Key,
+          class T, // when void, treat it as a set.
+          class Hash,
+          class KeyEqual,
+          class Allocator>
+class table {
+    struct Bucket;
+    using ValueContainer =
+        typename std::vector<typename std::conditional_t<std::is_void_v<T>, Key, std::pair<Key, T>>, Allocator>;
+    using BucketAlloc = typename std::allocator_traits<Allocator>::template rebind_alloc<Bucket>;
+    using BucketAllocTraits = std::allocator_traits<BucketAlloc>;
+
+    static constexpr uint32_t BUCKET_DIST_INC = 1U << 8U;                    // skip 1 byte fingerprint
+    static constexpr uint32_t BUCKET_FINGERPRINT_MASK = BUCKET_DIST_INC - 1; // mask for 1 byte of fingerprint
+    static constexpr uint8_t INITIAL_SHIFTS = 64 - 3;                        // 2^(64-m_shift) number of buckets
+    static constexpr float DEFAULT_MAX_LOAD_FACTOR = 0.8F;
+
+public:
+    using key_type = Key;
+    using mapped_type = T;
+    using value_type = typename ValueContainer::value_type;
+    using size_type = typename ValueContainer::size_type;
+    using difference_type = typename ValueContainer::difference_type;
+    using hasher = Hash;
+    using key_equal = KeyEqual;
+    using allocator_type = typename ValueContainer::allocator_type;
+    using reference = typename ValueContainer::reference;
+    using const_reference = typename ValueContainer::const_reference;
+    using pointer = typename ValueContainer::pointer;
+    using const_pointer = typename ValueContainer::const_pointer;
+    using iterator = typename ValueContainer::iterator;
+    using const_iterator = typename ValueContainer::const_iterator;
+
+private:
+    struct Bucket {
+        uint32_t dist_and_fingerprint; // upper 3 byte: distance to original bucket. lower byte: fingerprint from hash
+        uint32_t value_idx;            // index into the m_values vector.
+    };
+    static_assert(std::is_trivially_destructible_v<Bucket>, "assert there's no need to call destructor / std::destroy");
+    static_assert(std::is_trivially_copyable_v<Bucket>, "assert we can just memset / memcpy");
+
+    ValueContainer m_values{}; // Contains all the key-value pairs in one densely stored container. No holes.
+    Bucket* m_buckets_start = nullptr;
+    Bucket* m_buckets_end = nullptr;
+    uint32_t m_max_bucket_capacity = 0;
+    float m_max_load_factor = DEFAULT_MAX_LOAD_FACTOR;
+    Hash m_hash{};
+    KeyEqual m_equal{};
+    uint8_t m_shifts = INITIAL_SHIFTS;
+
+    [[nodiscard]] auto next(Bucket const* bucket) const -> Bucket const* {
+        return ANKERL_UNORDERED_DENSE_UNLIKELY(bucket + 1 == m_buckets_end) ? m_buckets_start : bucket + 1;
+    }
+
+    [[nodiscard]] auto next(Bucket* bucket) -> Bucket* {
+        return ANKERL_UNORDERED_DENSE_UNLIKELY(bucket + 1 == m_buckets_end) ? m_buckets_start : bucket + 1;
+    }
+
+    template <typename K>
+    [[nodiscard]] constexpr auto mixed_hash(K const& key) const -> uint64_t {
+        if constexpr (is_detected_v<detect_avalanching, Hash>) {
+            return m_hash(key);
+        } else {
+            return wyhash::hash(m_hash(key));
+        }
+    }
+
+    [[nodiscard]] constexpr auto dist_and_fingerprint_from_hash(uint64_t hash) const -> uint32_t {
+        return BUCKET_DIST_INC | (hash & BUCKET_FINGERPRINT_MASK);
+    }
+
+    [[nodiscard]] constexpr auto bucket_from_hash(uint64_t hash) const -> Bucket const* {
+        return m_buckets_start + (hash >> m_shifts);
+    }
+
+    [[nodiscard]] constexpr auto bucket_from_hash(uint64_t hash) -> Bucket* {
+        return m_buckets_start + (hash >> m_shifts);
+    }
+
+    [[nodiscard]] static constexpr auto get_key(value_type const& vt) -> key_type const& {
+        if constexpr (std::is_void_v<T>) {
+            return vt;
+        } else {
+            return vt.first;
+        }
+    }
+
+    template <typename K>
+    [[nodiscard]] auto next_while_less(K const& key) -> std::pair<uint32_t, Bucket*> {
+        auto const& pair = std::as_const(*this).next_while_less(key);
+        return {pair.first, const_cast<Bucket*>(pair.second)}; // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    template <typename K>
+    [[nodiscard]] auto next_while_less(K const& key) const -> std::pair<uint32_t, Bucket const*> {
+        auto hash = mixed_hash(key);
+        auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
+        auto const* bucket = bucket_from_hash(hash);
+
+        while (dist_and_fingerprint < bucket->dist_and_fingerprint) {
+            dist_and_fingerprint += BUCKET_DIST_INC;
+            bucket = next(bucket);
+        }
+        return {dist_and_fingerprint, bucket};
+    }
+
+    void place_and_shift_up(Bucket bucket, Bucket* place) {
+        while (0 != place->dist_and_fingerprint) {
+            bucket = std::exchange(*place, bucket);
+            bucket.dist_and_fingerprint += BUCKET_DIST_INC;
+            place = next(place);
+        }
+        *place = bucket;
+    }
+
+    [[nodiscard]] static constexpr auto calc_num_buckets(uint8_t shifts) -> uint64_t {
+        return UINT64_C(1) << (64U - shifts);
+    }
+
+    [[nodiscard]] constexpr auto calc_shifts_for_size(size_t s) const -> uint8_t {
+        auto shifts = INITIAL_SHIFTS;
+        while (shifts > 0 && static_cast<uint64_t>(calc_num_buckets(shifts) * max_load_factor()) < s) {
+            --shifts;
+        }
+        return shifts;
+    }
+
+    // assumes m_values has data, m_buckets_start=m_buckets_end=nullptr, m_shifts is INITIAL_SHIFTS
+    void copy_buckets(table const& other) {
+        if (!empty()) {
+            m_shifts = other.m_shifts;
+            allocate_buckets_from_shift();
+            std::memcpy(m_buckets_start, other.m_buckets_start, sizeof(Bucket) * bucket_count());
+        }
+    }
+
+    /**
+     * True when no element can be added any more without increasing the size
+     */
+    [[nodiscard]] auto is_full() const -> bool {
+        return size() >= m_max_bucket_capacity;
+    }
+
+    void deallocate_buckets() {
+        auto bucket_alloc = BucketAlloc(m_values.get_allocator());
+        BucketAllocTraits::deallocate(bucket_alloc, m_buckets_start, bucket_count());
+        m_buckets_start = nullptr;
+        m_buckets_end = nullptr;
+        m_max_bucket_capacity = 0;
+    }
+
+    void allocate_buckets_from_shift() {
+        auto bucket_alloc = BucketAlloc(m_values.get_allocator());
+        auto num_buckets = calc_num_buckets(m_shifts);
+        m_buckets_start = BucketAllocTraits::allocate(bucket_alloc, num_buckets);
+        m_buckets_end = m_buckets_start + num_buckets;
+        m_max_bucket_capacity = static_cast<uint64_t>(num_buckets * max_load_factor());
+    }
+
+    void clear_buckets() {
+        if (m_buckets_start != nullptr) {
+            std::memset(m_buckets_start, 0, sizeof(Bucket) * bucket_count());
+        }
+    }
+
+    void clear_and_fill_buckets_from_values() {
+        clear_buckets();
+        for (uint32_t value_idx = 0, end_idx = static_cast<uint32_t>(m_values.size()); value_idx < end_idx; ++value_idx) {
+            auto const& key = get_key(m_values[value_idx]);
+            auto [dist_and_fingerprint, bucket] = next_while_less(key);
+
+            // we know for certain that key has not yet been inserted, so no need to check it.
+            place_and_shift_up({dist_and_fingerprint, value_idx}, bucket);
+        }
+    }
+
+    void increase_size() {
+        --m_shifts;
+        deallocate_buckets();
+        allocate_buckets_from_shift();
+        clear_and_fill_buckets_from_values();
+    }
+
+    void do_erase(Bucket* bucket) {
+        auto const value_idx_to_remove = bucket->value_idx;
+
+        // shift down until either empty or an element with correct spot is found
+        auto* next_bucket = next(bucket);
+        while (next_bucket->dist_and_fingerprint >= BUCKET_DIST_INC * 2) {
+            *bucket = {next_bucket->dist_and_fingerprint - BUCKET_DIST_INC, next_bucket->value_idx};
+            bucket = std::exchange(next_bucket, next(next_bucket));
+        }
+        *bucket = {};
+
+        // update m_values
+        if (value_idx_to_remove != m_values.size() - 1) {
+            // no luck, we'll have to replace the value with the last one and update the index accordingly
+            auto& val = m_values[value_idx_to_remove];
+            val = std::move(m_values.back());
+
+            // update the values_idx of the moved entry. No need to play the info game, just look until we find the values_idx
+            auto mh = mixed_hash(get_key(val));
+            bucket = bucket_from_hash(mh);
+
+            auto const values_idx_back = static_cast<uint32_t>(m_values.size() - 1);
+            while (values_idx_back != bucket->value_idx) {
+                bucket = next(bucket);
+            }
+            bucket->value_idx = value_idx_to_remove;
+        }
+        m_values.pop_back();
+    }
+
+    template <typename K>
+    auto do_erase_key(K&& key) -> size_t {
+        if (empty()) {
+            return 0;
+        }
+
+        auto [dist_and_fingerprint, bucket] = next_while_less(key);
+
+        while (dist_and_fingerprint == bucket->dist_and_fingerprint && !m_equal(key, get_key(m_values[bucket->value_idx]))) {
+            dist_and_fingerprint += BUCKET_DIST_INC;
+            bucket = next(bucket);
+        }
+
+        if (dist_and_fingerprint != bucket->dist_and_fingerprint) {
+            return 0;
+        }
+        do_erase(bucket);
+        return 1;
+    }
+
+    template <class K, class M>
+    auto do_insert_or_assign(K&& key, M&& mapped) -> std::pair<iterator, bool> {
+        auto it_isinserted = try_emplace(std::forward<K>(key), std::forward<M>(mapped));
+        if (!it_isinserted.second) {
+            it_isinserted.first->second = std::forward<M>(mapped);
+        }
+        return it_isinserted;
+    }
+
+    template <typename K, typename... Args>
+    auto do_try_emplace(K&& key, Args&&... args) -> std::pair<iterator, bool> {
+        if (is_full()) {
+            increase_size();
+        }
+
+        auto hash = mixed_hash(key);
+        auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
+        auto* bucket = bucket_from_hash(hash);
+
+        while (dist_and_fingerprint <= bucket->dist_and_fingerprint) {
+            if (dist_and_fingerprint == bucket->dist_and_fingerprint && m_equal(key, m_values[bucket->value_idx].first)) {
+                return {begin() + bucket->value_idx, false};
+            }
+            dist_and_fingerprint += BUCKET_DIST_INC;
+            bucket = next(bucket);
+        }
+
+        // emplace the new value. If that throws an exception, no harm done; index is still in a valid state
+        m_values.emplace_back(std::piecewise_construct,
+                              std::forward_as_tuple(std::forward<K>(key)),
+                              std::forward_as_tuple(std::forward<Args>(args)...));
+
+        // place element and shift up until we find an empty spot
+        uint32_t value_idx = static_cast<uint32_t>(m_values.size()) - 1;
+        place_and_shift_up({dist_and_fingerprint, value_idx}, bucket);
+        return {begin() + value_idx, true};
+    }
+
+    template <typename K>
+    auto do_find(K const& key) -> iterator {
+        if (empty()) {
+            return end();
+        }
+
+        auto mh = mixed_hash(key);
+        auto dist_and_fingerprint = dist_and_fingerprint_from_hash(mh);
+        auto const* bucket = bucket_from_hash(mh);
+
+        // unrolled loop. *Always* check a few directly, then enter the loop. This is faster.
+        if (dist_and_fingerprint == bucket->dist_and_fingerprint && m_equal(key, get_key(m_values[bucket->value_idx]))) {
+            return begin() + bucket->value_idx;
+        }
+        dist_and_fingerprint += BUCKET_DIST_INC;
+        bucket = next(bucket);
+
+        if (dist_and_fingerprint == bucket->dist_and_fingerprint && m_equal(key, get_key(m_values[bucket->value_idx]))) {
+            return begin() + bucket->value_idx;
+        }
+        dist_and_fingerprint += BUCKET_DIST_INC;
+        bucket = next(bucket);
+
+        do {
+            if (dist_and_fingerprint == bucket->dist_and_fingerprint && m_equal(key, get_key(m_values[bucket->value_idx]))) {
+                return begin() + bucket->value_idx;
+            }
+            dist_and_fingerprint += BUCKET_DIST_INC;
+            bucket = next(bucket);
+        } while (dist_and_fingerprint <= bucket->dist_and_fingerprint);
+        return end();
+    }
+
+    template <typename K>
+    auto do_find(K const& key) const -> const_iterator {
+        return const_cast<table*>(this)->do_find(key); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+public:
+    table()
+        : table(0) {}
+
+    explicit table(size_t /*bucket_count*/,
+                   Hash const& hash = Hash(),
+                   KeyEqual const& equal = KeyEqual(),
+                   Allocator const& alloc = Allocator())
+        : m_values(alloc)
+        , m_hash(hash)
+        , m_equal(equal) {}
+
+    table(size_t bucket_count, Allocator const& alloc)
+        : table(bucket_count, Hash(), KeyEqual(), alloc) {}
+
+    table(size_t bucket_count, Hash const& hash, Allocator const& alloc)
+        : table(bucket_count, hash, KeyEqual(), alloc) {}
+
+    explicit table(Allocator const& alloc)
+        : table(0, Hash(), KeyEqual(), alloc) {}
+
+    template <class InputIt>
+    table(InputIt first,
+          InputIt last,
+          size_type bucket_count = 0,
+          Hash const& hash = Hash(),
+          KeyEqual const& equal = KeyEqual(),
+          Allocator const& alloc = Allocator())
+        : table(bucket_count, hash, equal, alloc) {
+        insert(first, last);
+    }
+
+    template <class InputIt>
+    table(InputIt first, InputIt last, size_type bucket_count, Allocator const& alloc)
+        : table(first, last, bucket_count, Hash(), KeyEqual(), alloc) {}
+
+    template <class InputIt>
+    table(InputIt first, InputIt last, size_type bucket_count, Hash const& hash, Allocator const& alloc)
+        : table(first, last, bucket_count, hash, KeyEqual(), alloc) {}
+
+    table(table const& other)
+        : table(other, other.m_values.get_allocator()) {}
+
+    table(table const& other, Allocator const& alloc)
+        : m_values(other.m_values, alloc)
+        , m_max_load_factor(other.m_max_load_factor)
+        , m_hash(other.m_hash)
+        , m_equal(other.m_equal) {
+        copy_buckets(other);
+    }
+
+    table(table&& other) noexcept
+        : table(std::move(other), other.m_values.get_allocator()) {}
+
+    table(table&& other, Allocator const& alloc) noexcept
+        : m_values(std::move(other.m_values), alloc)
+        , m_buckets_start(std::exchange(other.m_buckets_start, nullptr))
+        , m_buckets_end(std::exchange(other.m_buckets_end, nullptr))
+        , m_max_bucket_capacity(std::exchange(other.m_max_bucket_capacity, 0))
+        , m_max_load_factor(std::exchange(other.m_max_load_factor, DEFAULT_MAX_LOAD_FACTOR))
+        , m_hash(std::exchange(other.m_hash, {}))
+        , m_equal(std::exchange(other.m_equal, {}))
+        , m_shifts(std::exchange(other.m_shifts, INITIAL_SHIFTS)) {
+        other.m_values.clear();
+    }
+
+    table(std::initializer_list<value_type> ilist,
+          size_t bucket_count = 0,
+          Hash const& hash = Hash(),
+          KeyEqual const& equal = KeyEqual(),
+          Allocator const& alloc = Allocator())
+        : table(bucket_count, hash, equal, alloc) {
+        insert(ilist);
+    }
+
+    table(std::initializer_list<value_type> ilist, size_type bucket_count, const Allocator& alloc)
+        : table(ilist, bucket_count, Hash(), KeyEqual(), alloc) {}
+
+    table(std::initializer_list<value_type> init, size_type bucket_count, Hash const& hash, Allocator const& alloc)
+        : table(init, bucket_count, hash, KeyEqual(), alloc) {}
+
+    ~table() {
+        auto bucket_alloc = BucketAlloc(m_values.get_allocator());
+        BucketAllocTraits::deallocate(bucket_alloc, m_buckets_start, bucket_count());
+    }
+
+    auto operator=(table const& other) -> table& {
+        if (&other != this) {
+            deallocate_buckets(); // deallocate before m_values is set (might have another allocator)
+            m_values = other.m_values;
+            m_max_load_factor = other.m_max_load_factor;
+            m_hash = other.m_hash;
+            m_equal = other.m_equal;
+            m_shifts = INITIAL_SHIFTS;
+            copy_buckets(other);
+        }
+        return *this;
+    }
+
+    auto operator=(table&& other) noexcept(
+        noexcept(std::is_nothrow_move_assignable_v<ValueContainer>&& std::is_nothrow_move_assignable_v<Hash>&&
+                     std::is_nothrow_move_assignable_v<KeyEqual>)) -> table& {
+        if (&other != this) {
+            deallocate_buckets(); // deallocate before m_values is set (might have another allocator)
+            m_values = std::move(other.m_values);
+            m_buckets_start = std::exchange(other.m_buckets_start, nullptr);
+            m_buckets_end = std::exchange(other.m_buckets_end, nullptr);
+            m_max_bucket_capacity = std::exchange(other.m_max_bucket_capacity, 0);
+            m_max_load_factor = std::exchange(other.m_max_load_factor, DEFAULT_MAX_LOAD_FACTOR);
+            m_hash = std::exchange(other.m_hash, {});
+            m_equal = std::exchange(other.m_equal, {});
+            m_shifts = std::exchange(other.m_shifts, INITIAL_SHIFTS);
+            other.m_values.clear();
+        }
+        return *this;
+    }
+
+    auto operator=(std::initializer_list<value_type> ilist) -> table& {
+        clear();
+        insert(ilist);
+        return *this;
+    }
+
+    auto get_allocator() const noexcept -> allocator_type {
+        return m_values.get_allocator();
+    }
+
+    // iterators //////////////////////////////////////////////////////////////
+
+    auto begin() noexcept -> iterator {
+        return m_values.begin();
+    }
+
+    auto begin() const noexcept -> const_iterator {
+        return m_values.begin();
+    }
+
+    auto cbegin() const noexcept -> const_iterator {
+        return m_values.cbegin();
+    }
+
+    auto end() noexcept -> iterator {
+        return m_values.end();
+    }
+
+    auto cend() const noexcept -> const_iterator {
+        return m_values.cend();
+    }
+
+    auto end() const noexcept -> const_iterator {
+        return m_values.end();
+    }
+
+    // capacity ///////////////////////////////////////////////////////////////
+
+    [[nodiscard]] auto empty() const noexcept -> bool {
+        return m_values.empty();
+    }
+
+    [[nodiscard]] auto size() const noexcept -> size_t {
+        return m_values.size();
+    }
+
+    [[nodiscard]] auto max_size() const noexcept -> size_t {
+        return std::numeric_limits<uint32_t>::max();
+    }
+
+    // modifiers //////////////////////////////////////////////////////////////
+
+    void clear() {
+        m_values.clear();
+        clear_buckets();
+    }
+
+    auto insert(value_type const& value) -> std::pair<iterator, bool> {
+        return emplace(value);
+    }
+
+    auto insert(value_type&& value) -> std::pair<iterator, bool> {
+        return emplace(std::move(value));
+    }
+
+    template <class P, std::enable_if_t<std::is_constructible_v<value_type, P&&>, bool> = true>
+    auto insert(P&& value) -> std::pair<iterator, bool> {
+        return emplace(std::forward<P>(value));
+    }
+
+    auto insert(const_iterator /*hint*/, value_type const& value) -> iterator {
+        return insert(value).first;
+    }
+
+    auto insert(const_iterator /*hint*/, value_type&& value) -> iterator {
+        return insert(std::move(value)).first;
+    }
+
+    template <class P, std::enable_if_t<std::is_constructible_v<value_type, P&&>, bool> = true>
+    auto insert(const_iterator /*hint*/, P&& value) -> iterator {
+        return insert(std::forward<P>(value)).first;
+    }
+
+    template <class InputIt>
+    void insert(InputIt first, InputIt last) {
+        while (first != last) {
+            insert(*first);
+            ++first;
+        }
+    }
+
+    void insert(std::initializer_list<value_type> ilist) {
+        insert(ilist.begin(), ilist.end());
+    }
+
+    template <class M, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto insert_or_assign(Key const& key, M&& mapped) -> std::pair<iterator, bool> {
+        return do_insert_or_assign(key, std::forward<M>(mapped));
+    }
+
+    template <class M, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto insert_or_assign(Key&& key, M&& mapped) -> std::pair<iterator, bool> {
+        return do_insert_or_assign(std::move(key), std::forward<M>(mapped));
+    }
+
+    template <class M, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto insert_or_assign(const_iterator /*hint*/, Key const& key, M&& mapped) -> iterator {
+        return do_insert_or_assign(key, std::forward<M>(mapped)).first;
+    }
+
+    template <class M, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto insert_or_assign(const_iterator /*hint*/, Key&& key, M&& mapped) -> iterator {
+        return do_insert_or_assign(std::move(key), std::forward<M>(mapped)).first;
+    }
+
+    template <class... Args>
+    auto emplace(Args&&... args) -> std::pair<iterator, bool> {
+        if (is_full()) {
+            increase_size();
+        }
+
+        // first emplace_back the object so it is constructed. If the key is already there, pop it.
+        auto& val = m_values.emplace_back(std::forward<Args>(args)...);
+        auto hash = mixed_hash(get_key(val));
+        auto dist_and_fingerprint = dist_and_fingerprint_from_hash(hash);
+        auto* bucket = bucket_from_hash(hash);
+
+        while (dist_and_fingerprint <= bucket->dist_and_fingerprint) {
+            if (dist_and_fingerprint == bucket->dist_and_fingerprint &&
+                m_equal(get_key(val), get_key(m_values[bucket->value_idx]))) {
+                m_values.pop_back(); // value was already there, so get rid of it
+                return {begin() + bucket->value_idx, false};
+            }
+            dist_and_fingerprint += BUCKET_DIST_INC;
+            bucket = next(bucket);
+        }
+
+        // value is new, place the bucket and shift up until we find an empty spot
+        uint32_t value_idx = static_cast<uint32_t>(m_values.size()) - 1;
+        place_and_shift_up({dist_and_fingerprint, value_idx}, bucket);
+
+        return {begin() + value_idx, true};
+    }
+
+    template <class... Args>
+    auto emplace_hint(const_iterator /*hint*/, Args&&... args) -> iterator {
+        return emplace(std::forward<Args>(args)...).first;
+    }
+
+    template <class... Args, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto try_emplace(Key const& key, Args&&... args) -> std::pair<iterator, bool> {
+        return do_try_emplace(key, std::forward<Args>(args)...);
+    }
+
+    template <class... Args, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto try_emplace(Key&& key, Args&&... args) -> std::pair<iterator, bool> {
+        return do_try_emplace(std::move(key), std::forward<Args>(args)...);
+    }
+
+    template <class... Args, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto try_emplace(const_iterator /*hint*/, Key const& key, Args&&... args) -> iterator {
+        return do_try_emplace(key, std::forward<Args>(args)...).first;
+    }
+
+    template <class... Args, typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto try_emplace(const_iterator /*hint*/, Key&& key, Args&&... args) -> iterator {
+        return do_try_emplace(std::move(key), std::forward<Args>(args)...).first;
+    }
+
+    auto erase(iterator it) -> iterator {
+        auto hash = mixed_hash(get_key(*it));
+        auto* bucket = bucket_from_hash(hash);
+
+        auto const value_idx_to_remove = static_cast<uint32_t>(it - cbegin());
+        while (bucket->value_idx != value_idx_to_remove) {
+            bucket = next(bucket);
+        }
+
+        do_erase(bucket);
+        return begin() + value_idx_to_remove;
+    }
+
+    auto erase(const_iterator it) -> iterator {
+        return erase(begin() + (it - cbegin()));
+    }
+
+    auto erase(const_iterator first, const_iterator last) -> iterator {
+        auto const idx_first = first - cbegin();
+        auto const idx_last = last - cbegin();
+        auto const first_to_last = std::distance(first, last);
+        auto const last_to_end = std::distance(last, cend());
+
+        // remove elements from left to right which moves elements from the end back
+        auto const mid = idx_first + std::min(first_to_last, last_to_end);
+        auto idx = idx_first;
+        while (idx != mid) {
+            erase(begin() + idx);
+            ++idx;
+        }
+
+        // all elements from the right are moved, now remove the last element until all done
+        idx = idx_last;
+        while (idx != mid) {
+            --idx;
+            erase(begin() + idx);
+        }
+
+        return begin() + idx_first;
+    }
+
+    auto erase(Key const& key) -> size_t {
+        return do_erase_key(key);
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto erase(K&& key) -> size_t {
+        return do_erase_key(std::forward<K>(key));
+    }
+
+    void swap(table& other) noexcept(noexcept(std::is_nothrow_swappable_v<ValueContainer>&& std::is_nothrow_swappable_v<Hash>&&
+                                                  std::is_nothrow_swappable_v<KeyEqual>)) {
+        using std::swap;
+        swap(other, *this);
+    }
+
+    // lookup /////////////////////////////////////////////////////////////////
+
+    template <typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto at(key_type const& key) -> Q& {
+        if (auto it = find(key); end() != it) {
+            return it->second;
+        }
+        throw std::out_of_range("ankerl::unordered_dense::map::at(): key not found");
+    } // LCOV_EXCL_LINE is this a gcov/lcov bug? this method is fully tested.
+
+    template <typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto at(key_type const& key) const -> Q const& {
+        return const_cast<table*>(this)->at(key); // NOLINT(cppcoreguidelines-pro-type-const-cast)
+    }
+
+    template <typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto operator[](Key const& key) -> Q& {
+        return try_emplace(key).first->second;
+    }
+
+    template <typename Q = T, std::enable_if_t<!std::is_void_v<Q>, bool> = true>
+    auto operator[](Key&& key) -> Q& {
+        return try_emplace(std::move(key)).first->second;
+    }
+
+    auto count(Key const& key) const -> size_t {
+        return find(key) == end() ? 0 : 1;
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto count(K const& key) const -> size_t {
+        return find(key) == end() ? 0 : 1;
+    }
+
+    auto find(Key const& key) -> iterator {
+        return do_find(key);
+    }
+
+    auto find(Key const& key) const -> const_iterator {
+        return do_find(key);
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto find(K const& key) -> iterator {
+        return do_find(key);
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto find(K const& key) const -> const_iterator {
+        return do_find(key);
+    }
+
+    auto contains(Key const& key) const -> size_t {
+        return find(key) != end();
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto contains(K const& key) const -> size_t {
+        return find(key) != end();
+    }
+
+    auto equal_range(Key const& key) -> std::pair<iterator, iterator> {
+        auto it = do_find(key);
+        return {it, it == end() ? end() : it + 1};
+    }
+
+    auto equal_range(const Key& key) const -> std::pair<const_iterator, const_iterator> {
+        auto it = do_find(key);
+        return {it, it == end() ? end() : it + 1};
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto equal_range(K const& key) -> std::pair<iterator, iterator> {
+        auto it = do_find(key);
+        return {it, it == end() ? end() : it + 1};
+    }
+
+    template <class K, class H = Hash, class KE = KeyEqual, is_transparent<H, KE> = true>
+    auto equal_range(K const& key) const -> std::pair<const_iterator, const_iterator> {
+        auto it = do_find(key);
+        return {it, it == end() ? end() : it + 1};
+    }
+
+    // bucket interface ///////////////////////////////////////////////////////
+
+    auto bucket_count() const noexcept -> size_t { // NOLINT(modernize-use-nodiscard)
+        return m_buckets_end - m_buckets_start;
+    }
+
+    auto max_bucket_count() const noexcept -> size_t { // NOLINT(modernize-use-nodiscard)
+        return std::numeric_limits<uint32_t>::max();
+    }
+
+    // hash policy ////////////////////////////////////////////////////////////
+
+    [[nodiscard]] auto load_factor() const -> float {
+        return bucket_count() ? static_cast<float>(size()) / bucket_count() : 0.0F;
+    }
+
+    [[nodiscard]] auto max_load_factor() const -> float {
+        return m_max_load_factor;
+    }
+
+    void max_load_factor(float ml) {
+        m_max_load_factor = ml;
+        m_max_bucket_capacity = static_cast<uint32_t>(bucket_count() * max_load_factor());
+    }
+
+    void rehash(size_t count) {
+        auto shifts = calc_shifts_for_size(std::max(count, size()));
+        if (shifts != m_shifts) {
+            m_shifts = shifts;
+            deallocate_buckets();
+            m_values.shrink_to_fit();
+            allocate_buckets_from_shift();
+            clear_and_fill_buckets_from_values();
+        }
+    }
+
+    void reserve(size_t capa) {
+        auto shifts = calc_shifts_for_size(std::max(capa, size()));
+        if (shifts < m_shifts) {
+            m_shifts = shifts;
+            deallocate_buckets();
+            allocate_buckets_from_shift();
+            clear_and_fill_buckets_from_values();
+        }
+    }
+
+    // observers //////////////////////////////////////////////////////////////
+
+    auto hash_function() const -> hasher {
+        return m_hash;
+    }
+
+    auto key_eq() const -> key_equal {
+        return m_equal;
+    }
+
+    // non-member functions ///////////////////////////////////////////////////
+
+    friend auto operator==(table const& a, table const& b) -> bool {
+        if (&a == &b) {
+            return true;
+        }
+        if (a.size() != b.size()) {
+            return false;
+        }
+        for (auto const& b_entry : b) {
+            auto it = a.find(get_key(b_entry));
+            if constexpr (std::is_void_v<T>) {
+                // set: only check that the key is here
+                if (a.end() == it) {
+                    return false;
+                }
+            } else {
+                // map: check that key is here, then also check that value is the same
+                if (a.end() == it || !(b_entry.second == it->second)) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    friend auto operator!=(table const& a, table const& b) -> bool {
+        return !(a == b);
+    }
+};
+
+} // namespace detail
+
+template <class Key,
+          class T,
+          class Hash = hash<Key>,
+          class KeyEqual = std::equal_to<Key>,
+          class Allocator = std::allocator<std::pair<Key, T>>>
+using map = detail::table<Key, T, Hash, KeyEqual, Allocator>;
+
+template <class Key, class Hash = hash<Key>, class KeyEqual = std::equal_to<Key>, class Allocator = std::allocator<Key>>
+using set = detail::table<Key, void, Hash, KeyEqual, Allocator>;
+
+#    if ANKERL_UNORDERED_DENSE_PMR
+
+namespace pmr {
+
+template <class Key, class T, class Hash = hash<Key>, class KeyEqual = std::equal_to<Key>>
+using map = detail::table<Key, T, Hash, KeyEqual, std::pmr::polymorphic_allocator<std::pair<Key, T>>>;
+
+template <class Key, class Hash = hash<Key>, class KeyEqual = std::equal_to<Key>>
+using set = detail::table<Key, void, Hash, KeyEqual, std::pmr::polymorphic_allocator<Key>>;
+
+} // namespace pmr
+
+#    endif
+
+// deduction guides ///////////////////////////////////////////////////////////
+
+// deduction guides for alias templates are only possible since C++20
+// see https://en.cppreference.com/w/cpp/language/class_template_argument_deduction
+
+} // namespace ankerl::unordered_dense
+
+// std extensions /////////////////////////////////////////////////////////////
+
+namespace std { // NOLINT(cert-dcl58-cpp)
+
+template <class Key, class T, class Hash, class KeyEqual, class Allocator, class Pred>
+auto erase_if(ankerl::unordered_dense::detail::table<Key, T, Hash, KeyEqual, Allocator>& map, Pred pred) -> size_t {
+    // going back to front because erase() invalidates the end iterator
+    auto const old_size = map.size();
+    auto idx = old_size;
+    while (idx) {
+        --idx;
+        auto it = map.begin() + idx;
+        if (pred(*it)) {
+            map.erase(it);
+        }
+    }
+
+    return map.size() - old_size;
+}
+
+} // namespace std
+
+#endif
+#endif
diff --git a/contrib/robin-hood/robin_hood.h b/contrib/robin-hood/robin_hood.h
deleted file mode 100644
index 9141848d7..000000000
--- a/contrib/robin-hood/robin_hood.h
+++ /dev/null
@@ -1,2430 +0,0 @@
-//                 ______  _____                 ______                _________
-//  ______________ ___  /_ ___(_)_______         ___  /_ ______ ______ ______  /
-//  __  ___/_  __ \__  __ \__  / __  __ \        __  __ \_  __ \_  __ \_  __  /
-//  _  /    / /_/ /_  /_/ /_  /  _  / / /        _  / / // /_/ // /_/ // /_/ /
-//  /_/     \____/ /_.___/ /_/   /_/ /_/ ________/_/ /_/ \____/ \____/ \__,_/
-//                                      _/_____/
-//
-// Fast & memory efficient hashtable based on robin hood hashing for C++11/14/17/20
-// https://github.com/martinus/robin-hood-hashing
-//
-// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2018-2020 Martin Ankerl <http://martin.ankerl.com>
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all
-// copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-// SOFTWARE.
-
-#ifndef ROBIN_HOOD_H_INCLUDED
-#define ROBIN_HOOD_H_INCLUDED
-
-// see https://semver.org/
-#define ROBIN_HOOD_VERSION_MAJOR 3 // for incompatible API changes
-#define ROBIN_HOOD_VERSION_MINOR 9 // for adding functionality in a backwards-compatible manner
-#define ROBIN_HOOD_VERSION_PATCH 1 // for backwards-compatible bug fixes
-
-#include <algorithm>
-#include <cstdlib>
-#include <cstring>
-#include <functional>
-#include <limits>
-#include <memory> // only to support hash of smart pointers
-#include <stdexcept>
-#include <string>
-#include <type_traits>
-#include <utility>
-#if __cplusplus >= 201703L
-#    include <string_view>
-#endif
-
-// #define ROBIN_HOOD_LOG_ENABLED
-#ifdef ROBIN_HOOD_LOG_ENABLED
-#    include <iostream>
-#    define ROBIN_HOOD_LOG(...) \
-        std::cout << __FUNCTION__ << "@" << __LINE__ << ": " << __VA_ARGS__ << std::endl;
-#else
-#    define ROBIN_HOOD_LOG(x)
-#endif
-
-// #define ROBIN_HOOD_TRACE_ENABLED
-#ifdef ROBIN_HOOD_TRACE_ENABLED
-#    include <iostream>
-#    define ROBIN_HOOD_TRACE(...) \
-        std::cout << __FUNCTION__ << "@" << __LINE__ << ": " << __VA_ARGS__ << std::endl;
-#else
-#    define ROBIN_HOOD_TRACE(x)
-#endif
-
-// #define ROBIN_HOOD_COUNT_ENABLED
-#ifdef ROBIN_HOOD_COUNT_ENABLED
-#    include <iostream>
-#    define ROBIN_HOOD_COUNT(x) ++counts().x;
-namespace robin_hood {
-struct Counts {
-    uint64_t shiftUp{};
-    uint64_t shiftDown{};
-};
-inline std::ostream& operator<<(std::ostream& os, Counts const& c) {
-    return os << c.shiftUp << " shiftUp" << std::endl << c.shiftDown << " shiftDown" << std::endl;
-}
-
-static Counts& counts() {
-    static Counts counts{};
-    return counts;
-}
-} // namespace robin_hood
-#else
-#    define ROBIN_HOOD_COUNT(x)
-#endif
-
-// all non-argument macros should use this facility. See
-// https://www.fluentcpp.com/2019/05/28/better-macros-better-flags/
-#define ROBIN_HOOD(x) ROBIN_HOOD_PRIVATE_DEFINITION_##x()
-
-// mark unused members with this macro
-#define ROBIN_HOOD_UNUSED(identifier)
-
-// bitness
-#if SIZE_MAX == UINT32_MAX
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_BITNESS() 32
-#elif SIZE_MAX == UINT64_MAX
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_BITNESS() 64
-#else
-#    error Unsupported bitness
-#endif
-
-// endianess
-#ifdef _MSC_VER
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_LITTLE_ENDIAN() 1
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_BIG_ENDIAN() 0
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_LITTLE_ENDIAN() \
-        (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_BIG_ENDIAN() (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
-#endif
-
-// inline
-#ifdef _MSC_VER
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_NOINLINE() __declspec(noinline)
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_NOINLINE() __attribute__((noinline))
-#endif
-
-// exceptions
-#if !defined(__cpp_exceptions) && !defined(__EXCEPTIONS) && !defined(_CPPUNWIND)
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_EXCEPTIONS() 0
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_EXCEPTIONS() 1
-#endif
-
-// count leading/trailing bits
-#if !defined(ROBIN_HOOD_DISABLE_INTRINSICS)
-#    ifdef _MSC_VER
-#        if ROBIN_HOOD(BITNESS) == 32
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_BITSCANFORWARD() _BitScanForward
-#        else
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_BITSCANFORWARD() _BitScanForward64
-#        endif
-#        include <intrin.h>
-#        pragma intrinsic(ROBIN_HOOD(BITSCANFORWARD))
-#        define ROBIN_HOOD_COUNT_TRAILING_ZEROES(x)                                       \
-            [](size_t mask) noexcept -> int {                                             \
-                unsigned long index;                                                      \
-                return ROBIN_HOOD(BITSCANFORWARD)(&index, mask) ? static_cast<int>(index) \
-                                                                : ROBIN_HOOD(BITNESS);    \
-            }(x)
-#    else
-#        if ROBIN_HOOD(BITNESS) == 32
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_CTZ() __builtin_ctzl
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_CLZ() __builtin_clzl
-#        else
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_CTZ() __builtin_ctzll
-#            define ROBIN_HOOD_PRIVATE_DEFINITION_CLZ() __builtin_clzll
-#        endif
-#        define ROBIN_HOOD_COUNT_LEADING_ZEROES(x) ((x) ? ROBIN_HOOD(CLZ)(x) : ROBIN_HOOD(BITNESS))
-#        define ROBIN_HOOD_COUNT_TRAILING_ZEROES(x) ((x) ? ROBIN_HOOD(CTZ)(x) : ROBIN_HOOD(BITNESS))
-#    endif
-#endif
-
-// fallthrough
-#ifndef __has_cpp_attribute // For backwards compatibility
-#    define __has_cpp_attribute(x) 0
-#endif
-#if __has_cpp_attribute(clang::fallthrough)
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH() [[clang::fallthrough]]
-#elif __has_cpp_attribute(gnu::fallthrough)
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH() [[gnu::fallthrough]]
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH()
-#endif
-
-// likely/unlikely
-#ifdef _MSC_VER
-#    define ROBIN_HOOD_LIKELY(condition) condition
-#    define ROBIN_HOOD_UNLIKELY(condition) condition
-#else
-#    define ROBIN_HOOD_LIKELY(condition) __builtin_expect(condition, 1)
-#    define ROBIN_HOOD_UNLIKELY(condition) __builtin_expect(condition, 0)
-#endif
-
-// detect if native wchar_t type is availiable in MSVC
-#ifdef _MSC_VER
-#    ifdef _NATIVE_WCHAR_T_DEFINED
-#        define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 1
-#    else
-#        define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 0
-#    endif
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 1
-#endif
-
-// workaround missing "is_trivially_copyable" in g++ < 5.0
-// See https://stackoverflow.com/a/31798726/48181
-#if defined(__GNUC__) && __GNUC__ < 5
-#    define ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(...) __has_trivial_copy(__VA_ARGS__)
-#else
-#    define ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(...) std::is_trivially_copyable<__VA_ARGS__>::value
-#endif
-
-// helpers for C++ versions, see https://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html
-#define ROBIN_HOOD_PRIVATE_DEFINITION_CXX() __cplusplus
-#define ROBIN_HOOD_PRIVATE_DEFINITION_CXX98() 199711L
-#define ROBIN_HOOD_PRIVATE_DEFINITION_CXX11() 201103L
-#define ROBIN_HOOD_PRIVATE_DEFINITION_CXX14() 201402L
-#define ROBIN_HOOD_PRIVATE_DEFINITION_CXX17() 201703L
-
-#if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX17)
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_NODISCARD() [[nodiscard]]
-#else
-#    define ROBIN_HOOD_PRIVATE_DEFINITION_NODISCARD()
-#endif
-
-namespace robin_hood {
-
-#if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX14)
-#    define ROBIN_HOOD_STD std
-#else
-
-// c++11 compatibility layer
-namespace ROBIN_HOOD_STD {
-template <class T>
-struct alignment_of
-    : std::integral_constant<std::size_t, alignof(typename std::remove_all_extents<T>::type)> {};
-
-template <class T, T... Ints>
-class integer_sequence {
-public:
-    using value_type = T;
-    static_assert(std::is_integral<value_type>::value, "not integral type");
-    static constexpr std::size_t size() noexcept {
-        return sizeof...(Ints);
-    }
-};
-template <std::size_t... Inds>
-using index_sequence = integer_sequence<std::size_t, Inds...>;
-
-namespace detail_ {
-template <class T, T Begin, T End, bool>
-struct IntSeqImpl {
-    using TValue = T;
-    static_assert(std::is_integral<TValue>::value, "not integral type");
-    static_assert(Begin >= 0 && Begin < End, "unexpected argument (Begin<0 || Begin<=End)");
-
-    template <class, class>
-    struct IntSeqCombiner;
-
-    template <TValue... Inds0, TValue... Inds1>
-    struct IntSeqCombiner<integer_sequence<TValue, Inds0...>, integer_sequence<TValue, Inds1...>> {
-        using TResult = integer_sequence<TValue, Inds0..., Inds1...>;
-    };
-
-    using TResult =
-        typename IntSeqCombiner<typename IntSeqImpl<TValue, Begin, Begin + (End - Begin) / 2,
-                                                    (End - Begin) / 2 == 1>::TResult,
-                                typename IntSeqImpl<TValue, Begin + (End - Begin) / 2, End,
-                                                    (End - Begin + 1) / 2 == 1>::TResult>::TResult;
-};
-
-template <class T, T Begin>
-struct IntSeqImpl<T, Begin, Begin, false> {
-    using TValue = T;
-    static_assert(std::is_integral<TValue>::value, "not integral type");
-    static_assert(Begin >= 0, "unexpected argument (Begin<0)");
-    using TResult = integer_sequence<TValue>;
-};
-
-template <class T, T Begin, T End>
-struct IntSeqImpl<T, Begin, End, true> {
-    using TValue = T;
-    static_assert(std::is_integral<TValue>::value, "not integral type");
-    static_assert(Begin >= 0, "unexpected argument (Begin<0)");
-    using TResult = integer_sequence<TValue, Begin>;
-};
-} // namespace detail_
-
-template <class T, T N>
-using make_integer_sequence = typename detail_::IntSeqImpl<T, 0, N, (N - 0) == 1>::TResult;
-
-template <std::size_t N>
-using make_index_sequence = make_integer_sequence<std::size_t, N>;
-
-template <class... T>
-using index_sequence_for = make_index_sequence<sizeof...(T)>;
-
-} // namespace ROBIN_HOOD_STD
-
-#endif
-
-namespace detail {
-
-// make sure we static_cast to the correct type for hash_int
-#if ROBIN_HOOD(BITNESS) == 64
-using SizeT = uint64_t;
-#else
-using SizeT = uint32_t;
-#endif
-
-template <typename T>
-T rotr(T x, unsigned k) {
-    return (x >> k) | (x << (8U * sizeof(T) - k));
-}
-
-// This cast gets rid of warnings like "cast from 'uint8_t*' {aka 'unsigned char*'} to
-// 'uint64_t*' {aka 'long unsigned int*'} increases required alignment of target type". Use with
-// care!
-template <typename T>
-inline T reinterpret_cast_no_cast_align_warning(void* ptr) noexcept {
-    return reinterpret_cast<T>(ptr);
-}
-
-template <typename T>
-inline T reinterpret_cast_no_cast_align_warning(void const* ptr) noexcept {
-    return reinterpret_cast<T>(ptr);
-}
-
-// make sure this is not inlined as it is slow and dramatically enlarges code, thus making other
-// inlinings more difficult. Throws are also generally the slow path.
-template <typename E, typename... Args>
-[[noreturn]] ROBIN_HOOD(NOINLINE)
-#if ROBIN_HOOD(HAS_EXCEPTIONS)
-    void doThrow(Args&&... args) {
-    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-array-to-pointer-decay)
-    throw E(std::forward<Args>(args)...);
-}
-#else
-    void doThrow(Args&&... ROBIN_HOOD_UNUSED(args) /*unused*/) {
-    abort();
-}
-#endif
-
-template <typename E, typename T, typename... Args>
-T* assertNotNull(T* t, Args&&... args) {
-    if (ROBIN_HOOD_UNLIKELY(nullptr == t)) {
-        doThrow<E>(std::forward<Args>(args)...);
-    }
-    return t;
-}
-
-template <typename T>
-inline T unaligned_load(void const* ptr) noexcept {
-    // using memcpy so we don't get into unaligned load problems.
-    // compiler should optimize this very well anyways.
-    T t;
-    std::memcpy(&t, ptr, sizeof(T));
-    return t;
-}
-
-// Allocates bulks of memory for objects of type T. This deallocates the memory in the destructor,
-// and keeps a linked list of the allocated memory around. Overhead per allocation is the size of a
-// pointer.
-template <typename T, size_t MinNumAllocs = 4, size_t MaxNumAllocs = 256>
-class BulkPoolAllocator {
-public:
-    BulkPoolAllocator() noexcept = default;
-
-    // does not copy anything, just creates a new allocator.
-    BulkPoolAllocator(const BulkPoolAllocator& ROBIN_HOOD_UNUSED(o) /*unused*/) noexcept
-        : mHead(nullptr)
-        , mListForFree(nullptr) {}
-
-    BulkPoolAllocator(BulkPoolAllocator&& o) noexcept
-        : mHead(o.mHead)
-        , mListForFree(o.mListForFree) {
-        o.mListForFree = nullptr;
-        o.mHead = nullptr;
-    }
-
-    BulkPoolAllocator& operator=(BulkPoolAllocator&& o) noexcept {
-        reset();
-        mHead = o.mHead;
-        mListForFree = o.mListForFree;
-        o.mListForFree = nullptr;
-        o.mHead = nullptr;
-        return *this;
-    }
-
-    BulkPoolAllocator&
-    // NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp)
-    operator=(const BulkPoolAllocator& ROBIN_HOOD_UNUSED(o) /*unused*/) noexcept {
-        // does not do anything
-        return *this;
-    }
-
-    ~BulkPoolAllocator() noexcept {
-        reset();
-    }
-
-    // Deallocates all allocated memory.
-    void reset() noexcept {
-        while (mListForFree) {
-            T* tmp = *mListForFree;
-            ROBIN_HOOD_LOG("std::free")
-            std::free(mListForFree);
-            mListForFree = reinterpret_cast_no_cast_align_warning<T**>(tmp);
-        }
-        mHead = nullptr;
-    }
-
-    // allocates, but does NOT initialize. Use in-place new constructor, e.g.
-    //   T* obj = pool.allocate();
-    //   ::new (static_cast<void*>(obj)) T();
-    T* allocate() {
-        T* tmp = mHead;
-        if (!tmp) {
-            tmp = performAllocation();
-        }
-
-        mHead = *reinterpret_cast_no_cast_align_warning<T**>(tmp);
-        return tmp;
-    }
-
-    // does not actually deallocate but puts it in store.
-    // make sure you have already called the destructor! e.g. with
-    //  obj->~T();
-    //  pool.deallocate(obj);
-    void deallocate(T* obj) noexcept {
-        *reinterpret_cast_no_cast_align_warning<T**>(obj) = mHead;
-        mHead = obj;
-    }
-
-    // Adds an already allocated block of memory to the allocator. This allocator is from now on
-    // responsible for freeing the data (with free()). If the provided data is not large enough to
-    // make use of, it is immediately freed. Otherwise it is reused and freed in the destructor.
-    void addOrFree(void* ptr, const size_t numBytes) noexcept {
-        // calculate number of available elements in ptr
-        if (numBytes < ALIGNMENT + ALIGNED_SIZE) {
-            // not enough data for at least one element. Free and return.
-            ROBIN_HOOD_LOG("std::free")
-            std::free(ptr);
-        } else {
-            ROBIN_HOOD_LOG("add to buffer")
-            add(ptr, numBytes);
-        }
-    }
-
-    void swap(BulkPoolAllocator<T, MinNumAllocs, MaxNumAllocs>& other) noexcept {
-        using std::swap;
-        swap(mHead, other.mHead);
-        swap(mListForFree, other.mListForFree);
-    }
-
-private:
-    // iterates the list of allocated memory to calculate how many to alloc next.
-    // Recalculating this each time saves us a size_t member.
-    // This ignores the fact that memory blocks might have been added manually with addOrFree. In
-    // practice, this should not matter much.
-    ROBIN_HOOD(NODISCARD) size_t calcNumElementsToAlloc() const noexcept {
-        auto tmp = mListForFree;
-        size_t numAllocs = MinNumAllocs;
-
-        while (numAllocs * 2 <= MaxNumAllocs && tmp) {
-            auto x = reinterpret_cast<T***>(tmp);
-            tmp = *x;
-            numAllocs *= 2;
-        }
-
-        return numAllocs;
-    }
-
-    // WARNING: Underflow if numBytes < ALIGNMENT! This is guarded in addOrFree().
-    void add(void* ptr, const size_t numBytes) noexcept {
-        const size_t numElements = (numBytes - ALIGNMENT) / ALIGNED_SIZE;
-
-        auto data = reinterpret_cast<T**>(ptr);
-
-        // link free list
-        auto x = reinterpret_cast<T***>(data);
-        *x = mListForFree;
-        mListForFree = data;
-
-        // create linked list for newly allocated data
-        auto* const headT =
-            reinterpret_cast_no_cast_align_warning<T*>(reinterpret_cast<char*>(ptr) + ALIGNMENT);
-
-        auto* const head = reinterpret_cast<char*>(headT);
-
-        // Visual Studio compiler automatically unrolls this loop, which is pretty cool
-        for (size_t i = 0; i < numElements; ++i) {
-            *reinterpret_cast_no_cast_align_warning<char**>(head + i * ALIGNED_SIZE) =
-                head + (i + 1) * ALIGNED_SIZE;
-        }
-
-        // last one points to 0
-        *reinterpret_cast_no_cast_align_warning<T**>(head + (numElements - 1) * ALIGNED_SIZE) =
-            mHead;
-        mHead = headT;
-    }
-
-    // Called when no memory is available (mHead == 0).
-    // Don't inline this slow path.
-    ROBIN_HOOD(NOINLINE) T* performAllocation() {
-        size_t const numElementsToAlloc = calcNumElementsToAlloc();
-
-        // alloc new memory: [prev |T, T, ... T]
-        size_t const bytes = ALIGNMENT + ALIGNED_SIZE * numElementsToAlloc;
-        ROBIN_HOOD_LOG("std::malloc " << bytes << " = " << ALIGNMENT << " + " << ALIGNED_SIZE
-                                      << " * " << numElementsToAlloc)
-        add(assertNotNull<std::bad_alloc>(std::malloc(bytes)), bytes);
-        return mHead;
-    }
-
-    // enforce byte alignment of the T's
-#if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX14)
-    static constexpr size_t ALIGNMENT =
-        (std::max)(std::alignment_of<T>::value, std::alignment_of<T*>::value);
-#else
-    static const size_t ALIGNMENT =
-        (ROBIN_HOOD_STD::alignment_of<T>::value > ROBIN_HOOD_STD::alignment_of<T*>::value)
-            ? ROBIN_HOOD_STD::alignment_of<T>::value
-            : +ROBIN_HOOD_STD::alignment_of<T*>::value; // the + is for walkarround
-#endif
-
-    static constexpr size_t ALIGNED_SIZE = ((sizeof(T) - 1) / ALIGNMENT + 1) * ALIGNMENT;
-
-    static_assert(MinNumAllocs >= 1, "MinNumAllocs");
-    static_assert(MaxNumAllocs >= MinNumAllocs, "MaxNumAllocs");
-    static_assert(ALIGNED_SIZE >= sizeof(T*), "ALIGNED_SIZE");
-    static_assert(0 == (ALIGNED_SIZE % sizeof(T*)), "ALIGNED_SIZE mod");
-    static_assert(ALIGNMENT >= sizeof(T*), "ALIGNMENT");
-
-    T* mHead{nullptr};
-    T** mListForFree{nullptr};
-};
-
-template <typename T, size_t MinSize, size_t MaxSize, bool IsFlat>
-struct NodeAllocator;
-
-// dummy allocator that does nothing
-template <typename T, size_t MinSize, size_t MaxSize>
-struct NodeAllocator<T, MinSize, MaxSize, true> {
-
-    // we are not using the data, so just free it.
-    void addOrFree(void* ptr, size_t ROBIN_HOOD_UNUSED(numBytes) /*unused*/) noexcept {
-        ROBIN_HOOD_LOG("std::free")
-        std::free(ptr);
-    }
-};
-
-template <typename T, size_t MinSize, size_t MaxSize>
-struct NodeAllocator<T, MinSize, MaxSize, false> : public BulkPoolAllocator<T, MinSize, MaxSize> {};
-
-// dummy hash, unsed as mixer when robin_hood::hash is already used
-template <typename T>
-struct identity_hash {
-    constexpr size_t operator()(T const& obj) const noexcept {
-        return static_cast<size_t>(obj);
-    }
-};
-
-// c++14 doesn't have is_nothrow_swappable, and clang++ 6.0.1 doesn't like it either, so I'm making
-// my own here.
-namespace swappable {
-#if ROBIN_HOOD(CXX) < ROBIN_HOOD(CXX17)
-using std::swap;
-template <typename T>
-struct nothrow {
-    static const bool value = noexcept(swap(std::declval<T&>(), std::declval<T&>()));
-};
-#else
-template <typename T>
-struct nothrow {
-    static const bool value = std::is_nothrow_swappable<T>::value;
-};
-#endif
-} // namespace swappable
-
-} // namespace detail
-
-struct is_transparent_tag {};
-
-// A custom pair implementation is used in the map because std::pair is not is_trivially_copyable,
-// which means it would  not be allowed to be used in std::memcpy. This struct is copyable, which is
-// also tested.
-template <typename T1, typename T2>
-struct pair {
-    using first_type = T1;
-    using second_type = T2;
-
-    template <typename U1 = T1, typename U2 = T2,
-              typename = typename std::enable_if<std::is_default_constructible<U1>::value &&
-                                                 std::is_default_constructible<U2>::value>::type>
-    constexpr pair() noexcept(noexcept(U1()) && noexcept(U2()))
-        : first()
-        , second() {}
-
-    // pair constructors are explicit so we don't accidentally call this ctor when we don't have to.
-    explicit constexpr pair(std::pair<T1, T2> const& o) noexcept(
-        noexcept(T1(std::declval<T1 const&>())) && noexcept(T2(std::declval<T2 const&>())))
-        : first(o.first)
-        , second(o.second) {}
-
-    // pair constructors are explicit so we don't accidentally call this ctor when we don't have to.
-    explicit constexpr pair(std::pair<T1, T2>&& o) noexcept(noexcept(
-        T1(std::move(std::declval<T1&&>()))) && noexcept(T2(std::move(std::declval<T2&&>()))))
-        : first(std::move(o.first))
-        , second(std::move(o.second)) {}
-
-    constexpr pair(T1&& a, T2&& b) noexcept(noexcept(
-        T1(std::move(std::declval<T1&&>()))) && noexcept(T2(std::move(std::declval<T2&&>()))))
-        : first(std::move(a))
-        , second(std::move(b)) {}
-
-    template <typename U1, typename U2>
-    constexpr pair(U1&& a, U2&& b) noexcept(noexcept(T1(std::forward<U1>(
-        std::declval<U1&&>()))) && noexcept(T2(std::forward<U2>(std::declval<U2&&>()))))
-        : first(std::forward<U1>(a))
-        , second(std::forward<U2>(b)) {}
-
-    template <typename... U1, typename... U2>
-    constexpr pair(
-        std::piecewise_construct_t /*unused*/, std::tuple<U1...> a,
-        std::tuple<U2...> b) noexcept(noexcept(pair(std::declval<std::tuple<U1...>&>(),
-                                                    std::declval<std::tuple<U2...>&>(),
-                                                    ROBIN_HOOD_STD::index_sequence_for<U1...>(),
-                                                    ROBIN_HOOD_STD::index_sequence_for<U2...>())))
-        : pair(a, b, ROBIN_HOOD_STD::index_sequence_for<U1...>(),
-               ROBIN_HOOD_STD::index_sequence_for<U2...>()) {}
-
-    // constructor called from the std::piecewise_construct_t ctor
-    template <typename... U1, size_t... I1, typename... U2, size_t... I2>
-    pair(std::tuple<U1...>& a, std::tuple<U2...>& b, ROBIN_HOOD_STD::index_sequence<I1...> /*unused*/, ROBIN_HOOD_STD::index_sequence<I2...> /*unused*/) noexcept(
-        noexcept(T1(std::forward<U1>(std::get<I1>(
-            std::declval<std::tuple<
-                U1...>&>()))...)) && noexcept(T2(std::
-                                                     forward<U2>(std::get<I2>(
-                                                         std::declval<std::tuple<U2...>&>()))...)))
-        : first(std::forward<U1>(std::get<I1>(a))...)
-        , second(std::forward<U2>(std::get<I2>(b))...) {
-        // make visual studio compiler happy about warning about unused a & b.
-        // Visual studio's pair implementation disables warning 4100.
-        (void)a;
-        (void)b;
-    }
-
-    void swap(pair<T1, T2>& o) noexcept((detail::swappable::nothrow<T1>::value) &&
-                                        (detail::swappable::nothrow<T2>::value)) {
-        using std::swap;
-        swap(first, o.first);
-        swap(second, o.second);
-    }
-
-    T1 first;  // NOLINT(misc-non-private-member-variables-in-classes)
-    T2 second; // NOLINT(misc-non-private-member-variables-in-classes)
-};
-
-template <typename A, typename B>
-inline void swap(pair<A, B>& a, pair<A, B>& b) noexcept(
-    noexcept(std::declval<pair<A, B>&>().swap(std::declval<pair<A, B>&>()))) {
-    a.swap(b);
-}
-
-template <typename A, typename B>
-inline constexpr bool operator==(pair<A, B> const& x, pair<A, B> const& y) {
-    return (x.first == y.first) && (x.second == y.second);
-}
-template <typename A, typename B>
-inline constexpr bool operator!=(pair<A, B> const& x, pair<A, B> const& y) {
-    return !(x == y);
-}
-template <typename A, typename B>
-inline constexpr bool operator<(pair<A, B> const& x, pair<A, B> const& y) noexcept(noexcept(
-    std::declval<A const&>() < std::declval<A const&>()) && noexcept(std::declval<B const&>() <
-                                                                     std::declval<B const&>())) {
-    return x.first < y.first || (!(y.first < x.first) && x.second < y.second);
-}
-template <typename A, typename B>
-inline constexpr bool operator>(pair<A, B> const& x, pair<A, B> const& y) {
-    return y < x;
-}
-template <typename A, typename B>
-inline constexpr bool operator<=(pair<A, B> const& x, pair<A, B> const& y) {
-    return !(x > y);
-}
-template <typename A, typename B>
-inline constexpr bool operator>=(pair<A, B> const& x, pair<A, B> const& y) {
-    return !(x < y);
-}
-
-inline size_t hash_bytes(void const* ptr, size_t len) noexcept {
-    static constexpr uint64_t m = UINT64_C(0xc6a4a7935bd1e995);
-    static constexpr uint64_t seed = UINT64_C(0xe17a1465);
-    static constexpr unsigned int r = 47;
-
-    auto const* const data64 = static_cast<uint64_t const*>(ptr);
-    uint64_t h = seed ^ (len * m);
-
-    size_t const n_blocks = len / 8;
-    for (size_t i = 0; i < n_blocks; ++i) {
-        auto k = detail::unaligned_load<uint64_t>(data64 + i);
-
-        k *= m;
-        k ^= k >> r;
-        k *= m;
-
-        h ^= k;
-        h *= m;
-    }
-
-    auto const* const data8 = reinterpret_cast<uint8_t const*>(data64 + n_blocks);
-    switch (len & 7U) {
-    case 7:
-        h ^= static_cast<uint64_t>(data8[6]) << 48U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 6:
-        h ^= static_cast<uint64_t>(data8[5]) << 40U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 5:
-        h ^= static_cast<uint64_t>(data8[4]) << 32U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 4:
-        h ^= static_cast<uint64_t>(data8[3]) << 24U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 3:
-        h ^= static_cast<uint64_t>(data8[2]) << 16U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 2:
-        h ^= static_cast<uint64_t>(data8[1]) << 8U;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    case 1:
-        h ^= static_cast<uint64_t>(data8[0]);
-        h *= m;
-        ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH
-    default:
-        break;
-    }
-
-    h ^= h >> r;
-    h *= m;
-    h ^= h >> r;
-    return static_cast<size_t>(h);
-}
-
-inline size_t hash_int(uint64_t x) noexcept {
-    // inspired by lemire's strongly universal hashing
-    // https://lemire.me/blog/2018/08/15/fast-strongly-universal-64-bit-hashing-everywhere/
-    //
-    // Instead of shifts, we use rotations so we don't lose any bits.
-    //
-    // Added a final multiplcation with a constant for more mixing. It is most important that
-    // the lower bits are well mixed.
-    auto h1 = x * UINT64_C(0xA24BAED4963EE407);
-    auto h2 = detail::rotr(x, 32U) * UINT64_C(0x9FB21C651E98DF25);
-    auto h = detail::rotr(h1 + h2, 32U);
-    return static_cast<size_t>(h);
-}
-
-// A thin wrapper around std::hash, performing an additional simple mixing step of the result.
-template <typename T, typename Enable = void>
-struct hash : public std::hash<T> {
-    size_t operator()(T const& obj) const
-        noexcept(noexcept(std::declval<std::hash<T>>().operator()(std::declval<T const&>()))) {
-        // call base hash
-        auto result = std::hash<T>::operator()(obj);
-        // return mixed of that, to be save against identity has
-        return hash_int(static_cast<detail::SizeT>(result));
-    }
-};
-
-template <typename CharT>
-struct hash<std::basic_string<CharT>> {
-    size_t operator()(std::basic_string<CharT> const& str) const noexcept {
-        return hash_bytes(str.data(), sizeof(CharT) * str.size());
-    }
-};
-
-#if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX17)
-template <typename CharT>
-struct hash<std::basic_string_view<CharT>> {
-    size_t operator()(std::basic_string_view<CharT> const& sv) const noexcept {
-        return hash_bytes(sv.data(), sizeof(CharT) * sv.size());
-    }
-};
-#endif
-
-template <class T>
-struct hash<T*> {
-    size_t operator()(T* ptr) const noexcept {
-        return hash_int(reinterpret_cast<detail::SizeT>(ptr));
-    }
-};
-
-template <class T>
-struct hash<std::unique_ptr<T>> {
-    size_t operator()(std::unique_ptr<T> const& ptr) const noexcept {
-        return hash_int(reinterpret_cast<detail::SizeT>(ptr.get()));
-    }
-};
-
-template <class T>
-struct hash<std::shared_ptr<T>> {
-    size_t operator()(std::shared_ptr<T> const& ptr) const noexcept {
-        return hash_int(reinterpret_cast<detail::SizeT>(ptr.get()));
-    }
-};
-
-template <typename Enum>
-struct hash<Enum, typename std::enable_if<std::is_enum<Enum>::value>::type> {
-    size_t operator()(Enum e) const noexcept {
-        using Underlying = typename std::underlying_type<Enum>::type;
-        return hash<Underlying>{}(static_cast<Underlying>(e));
-    }
-};
-
-#define ROBIN_HOOD_HASH_INT(T)                           \
-    template <>                                          \
-    struct hash<T> {                                     \
-        size_t operator()(T const& obj) const noexcept { \
-            return hash_int(static_cast<uint64_t>(obj)); \
-        }                                                \
-    }
-
-#if defined(__GNUC__) && !defined(__clang__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wuseless-cast"
-#endif
-// see https://en.cppreference.com/w/cpp/utility/hash
-ROBIN_HOOD_HASH_INT(bool);
-ROBIN_HOOD_HASH_INT(char);
-ROBIN_HOOD_HASH_INT(signed char);
-ROBIN_HOOD_HASH_INT(unsigned char);
-ROBIN_HOOD_HASH_INT(char16_t);
-ROBIN_HOOD_HASH_INT(char32_t);
-#if ROBIN_HOOD(HAS_NATIVE_WCHART)
-ROBIN_HOOD_HASH_INT(wchar_t);
-#endif
-ROBIN_HOOD_HASH_INT(short);
-ROBIN_HOOD_HASH_INT(unsigned short);
-ROBIN_HOOD_HASH_INT(int);
-ROBIN_HOOD_HASH_INT(unsigned int);
-ROBIN_HOOD_HASH_INT(long);
-ROBIN_HOOD_HASH_INT(long long);
-ROBIN_HOOD_HASH_INT(unsigned long);
-ROBIN_HOOD_HASH_INT(unsigned long long);
-#if defined(__GNUC__) && !defined(__clang__)
-#    pragma GCC diagnostic pop
-#endif
-namespace detail {
-
-template <typename T>
-struct void_type {
-    using type = void;
-};
-
-template <typename T, typename = void>
-struct has_is_transparent : public std::false_type {};
-
-template <typename T>
-struct has_is_transparent<T, typename void_type<typename T::is_transparent>::type>
-    : public std::true_type {};
-
-// using wrapper classes for hash and key_equal prevents the diamond problem when the same type
-// is used. see https://stackoverflow.com/a/28771920/48181
-template <typename T>
-struct WrapHash : public T {
-    WrapHash() = default;
-    explicit WrapHash(T const& o) noexcept(noexcept(T(std::declval<T const&>())))
-        : T(o) {}
-};
-
-template <typename T>
-struct WrapKeyEqual : public T {
-    WrapKeyEqual() = default;
-    explicit WrapKeyEqual(T const& o) noexcept(noexcept(T(std::declval<T const&>())))
-        : T(o) {}
-};
-
-// A highly optimized hashmap implementation, using the Robin Hood algorithm.
-//
-// In most cases, this map should be usable as a drop-in replacement for std::unordered_map, but
-// be about 2x faster in most cases and require much less allocations.
-//
-// This implementation uses the following memory layout:
-//
-// [Node, Node, ... Node | info, info, ... infoSentinel ]
-//
-// * Node: either a DataNode that directly has the std::pair<key, val> as member,
-//   or a DataNode with a pointer to std::pair<key,val>. Which DataNode representation to use
-//   depends on how fast the swap() operation is. Heuristically, this is automatically choosen
-//   based on sizeof(). there are always 2^n Nodes.
-//
-// * info: Each Node in the map has a corresponding info byte, so there are 2^n info bytes.
-//   Each byte is initialized to 0, meaning the corresponding Node is empty. Set to 1 means the
-//   corresponding node contains data. Set to 2 means the corresponding Node is filled, but it
-//   actually belongs to the previous position and was pushed out because that place is already
-//   taken.
-//
-// * infoSentinel: Sentinel byte set to 1, so that iterator's ++ can stop at end() without the
-//   need for a idx variable.
-//
-// According to STL, order of templates has effect on throughput. That's why I've moved the
-// boolean to the front.
-// https://www.reddit.com/r/cpp/comments/ahp6iu/compile_time_binary_size_reductions_and_cs_future/eeguck4/
-template <bool IsFlat, size_t MaxLoadFactor100, typename Key, typename T, typename Hash,
-          typename KeyEqual>
-class Table
-    : public WrapHash<Hash>,
-      public WrapKeyEqual<KeyEqual>,
-      detail::NodeAllocator<
-          typename std::conditional<
-              std::is_void<T>::value, Key,
-              robin_hood::pair<typename std::conditional<IsFlat, Key, Key const>::type, T>>::type,
-          4, 16384, IsFlat> {
-public:
-    static constexpr bool is_flat = IsFlat;
-    static constexpr bool is_map = !std::is_void<T>::value;
-    static constexpr bool is_set = !is_map;
-    static constexpr bool is_transparent =
-        has_is_transparent<Hash>::value && has_is_transparent<KeyEqual>::value;
-
-    using key_type = Key;
-    using mapped_type = T;
-    using value_type = typename std::conditional<
-        is_set, Key,
-        robin_hood::pair<typename std::conditional<is_flat, Key, Key const>::type, T>>::type;
-    using size_type = size_t;
-    using hasher = Hash;
-    using key_equal = KeyEqual;
-    using Self = Table<IsFlat, MaxLoadFactor100, key_type, mapped_type, hasher, key_equal>;
-
-private:
-    static_assert(MaxLoadFactor100 > 10 && MaxLoadFactor100 < 100,
-                  "MaxLoadFactor100 needs to be >10 && < 100");
-
-    using WHash = WrapHash<Hash>;
-    using WKeyEqual = WrapKeyEqual<KeyEqual>;
-
-    // configuration defaults
-
-    // make sure we have 8 elements, needed to quickly rehash mInfo
-    static constexpr size_t InitialNumElements = sizeof(uint64_t);
-    static constexpr uint32_t InitialInfoNumBits = 5;
-    static constexpr uint8_t InitialInfoInc = 1U << InitialInfoNumBits;
-    static constexpr size_t InfoMask = InitialInfoInc - 1U;
-    static constexpr uint8_t InitialInfoHashShift = 0;
-    using DataPool = detail::NodeAllocator<value_type, 4, 16384, IsFlat>;
-
-    // type needs to be wider than uint8_t.
-    using InfoType = uint32_t;
-
-    // DataNode ////////////////////////////////////////////////////////
-
-    // Primary template for the data node. We have special implementations for small and big
-    // objects. For large objects it is assumed that swap() is fairly slow, so we allocate these
-    // on the heap so swap merely swaps a pointer.
-    template <typename M, bool>
-    class DataNode {};
-
-    // Small: just allocate on the stack.
-    template <typename M>
-    class DataNode<M, true> final {
-    public:
-        template <typename... Args>
-        explicit DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, Args&&... args) noexcept(
-            noexcept(value_type(std::forward<Args>(args)...)))
-            : mData(std::forward<Args>(args)...) {}
-
-        DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, DataNode<M, true>&& n) noexcept(
-            std::is_nothrow_move_constructible<value_type>::value)
-            : mData(std::move(n.mData)) {}
-
-        // doesn't do anything
-        void destroy(M& ROBIN_HOOD_UNUSED(map) /*unused*/) noexcept {}
-        void destroyDoNotDeallocate() noexcept {}
-
-        value_type const* operator->() const noexcept {
-            return &mData;
-        }
-        value_type* operator->() noexcept {
-            return &mData;
-        }
-
-        const value_type& operator*() const noexcept {
-            return mData;
-        }
-
-        value_type& operator*() noexcept {
-            return mData;
-        }
-
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, typename VT::first_type&>::type getFirst() noexcept {
-            return mData.first;
-        }
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_set, VT&>::type getFirst() noexcept {
-            return mData;
-        }
-
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, typename VT::first_type const&>::type
-            getFirst() const noexcept {
-            return mData.first;
-        }
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_set, VT const&>::type getFirst() const noexcept {
-            return mData;
-        }
-
-        template <typename MT = mapped_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, MT&>::type getSecond() noexcept {
-            return mData.second;
-        }
-
-        template <typename MT = mapped_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_set, MT const&>::type getSecond() const noexcept {
-            return mData.second;
-        }
-
-        void swap(DataNode<M, true>& o) noexcept(
-            noexcept(std::declval<value_type>().swap(std::declval<value_type>()))) {
-            mData.swap(o.mData);
-        }
-
-    private:
-        value_type mData;
-    };
-
-    // big object: allocate on heap.
-    template <typename M>
-    class DataNode<M, false> {
-    public:
-        template <typename... Args>
-        explicit DataNode(M& map, Args&&... args)
-            : mData(map.allocate()) {
-            ::new (static_cast<void*>(mData)) value_type(std::forward<Args>(args)...);
-        }
-
-        DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, DataNode<M, false>&& n) noexcept
-            : mData(std::move(n.mData)) {}
-
-        void destroy(M& map) noexcept {
-            // don't deallocate, just put it into list of datapool.
-            mData->~value_type();
-            map.deallocate(mData);
-        }
-
-        void destroyDoNotDeallocate() noexcept {
-            mData->~value_type();
-        }
-
-        value_type const* operator->() const noexcept {
-            return mData;
-        }
-
-        value_type* operator->() noexcept {
-            return mData;
-        }
-
-        const value_type& operator*() const {
-            return *mData;
-        }
-
-        value_type& operator*() {
-            return *mData;
-        }
-
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, typename VT::first_type&>::type getFirst() noexcept {
-            return mData->first;
-        }
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_set, VT&>::type getFirst() noexcept {
-            return *mData;
-        }
-
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, typename VT::first_type const&>::type
-            getFirst() const noexcept {
-            return mData->first;
-        }
-        template <typename VT = value_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_set, VT const&>::type getFirst() const noexcept {
-            return *mData;
-        }
-
-        template <typename MT = mapped_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, MT&>::type getSecond() noexcept {
-            return mData->second;
-        }
-
-        template <typename MT = mapped_type>
-        ROBIN_HOOD(NODISCARD)
-        typename std::enable_if<is_map, MT const&>::type getSecond() const noexcept {
-            return mData->second;
-        }
-
-        void swap(DataNode<M, false>& o) noexcept {
-            using std::swap;
-            swap(mData, o.mData);
-        }
-
-    private:
-        value_type* mData;
-    };
-
-    using Node = DataNode<Self, IsFlat>;
-
-    // helpers for doInsert: extract first entry (only const required)
-    ROBIN_HOOD(NODISCARD) key_type const& getFirstConst(Node const& n) const noexcept {
-        return n.getFirst();
-    }
-
-    // in case we have void mapped_type, we are not using a pair, thus we just route k through.
-    // No need to disable this because it's just not used if not applicable.
-    ROBIN_HOOD(NODISCARD) key_type const& getFirstConst(key_type const& k) const noexcept {
-        return k;
-    }
-
-    // in case we have non-void mapped_type, we have a standard robin_hood::pair
-    template <typename Q = mapped_type>
-    ROBIN_HOOD(NODISCARD)
-    typename std::enable_if<!std::is_void<Q>::value, key_type const&>::type
-        getFirstConst(value_type const& vt) const noexcept {
-        return vt.first;
-    }
-
-    // Cloner //////////////////////////////////////////////////////////
-
-    template <typename M, bool UseMemcpy>
-    struct Cloner;
-
-    // fast path: Just copy data, without allocating anything.
-    template <typename M>
-    struct Cloner<M, true> {
-        void operator()(M const& source, M& target) const {
-            auto const* const src = reinterpret_cast<char const*>(source.mKeyVals);
-            auto* tgt = reinterpret_cast<char*>(target.mKeyVals);
-            auto const numElementsWithBuffer = target.calcNumElementsWithBuffer(target.mMask + 1);
-            std::copy(src, src + target.calcNumBytesTotal(numElementsWithBuffer), tgt);
-        }
-    };
-
-    template <typename M>
-    struct Cloner<M, false> {
-        void operator()(M const& s, M& t) const {
-            auto const numElementsWithBuffer = t.calcNumElementsWithBuffer(t.mMask + 1);
-            std::copy(s.mInfo, s.mInfo + t.calcNumBytesInfo(numElementsWithBuffer), t.mInfo);
-
-            for (size_t i = 0; i < numElementsWithBuffer; ++i) {
-                if (t.mInfo[i]) {
-                    ::new (static_cast<void*>(t.mKeyVals + i)) Node(t, *s.mKeyVals[i]);
-                }
-            }
-        }
-    };
-
-    // Destroyer ///////////////////////////////////////////////////////
-
-    template <typename M, bool IsFlatAndTrivial>
-    struct Destroyer {};
-
-    template <typename M>
-    struct Destroyer<M, true> {
-        void nodes(M& m) const noexcept {
-            m.mNumElements = 0;
-        }
-
-        void nodesDoNotDeallocate(M& m) const noexcept {
-            m.mNumElements = 0;
-        }
-    };
-
-    template <typename M>
-    struct Destroyer<M, false> {
-        void nodes(M& m) const noexcept {
-            m.mNumElements = 0;
-            // clear also resets mInfo to 0, that's sometimes not necessary.
-            auto const numElementsWithBuffer = m.calcNumElementsWithBuffer(m.mMask + 1);
-
-            for (size_t idx = 0; idx < numElementsWithBuffer; ++idx) {
-                if (0 != m.mInfo[idx]) {
-                    Node& n = m.mKeyVals[idx];
-                    n.destroy(m);
-                    n.~Node();
-                }
-            }
-        }
-
-        void nodesDoNotDeallocate(M& m) const noexcept {
-            m.mNumElements = 0;
-            // clear also resets mInfo to 0, that's sometimes not necessary.
-            auto const numElementsWithBuffer = m.calcNumElementsWithBuffer(m.mMask + 1);
-            for (size_t idx = 0; idx < numElementsWithBuffer; ++idx) {
-                if (0 != m.mInfo[idx]) {
-                    Node& n = m.mKeyVals[idx];
-                    n.destroyDoNotDeallocate();
-                    n.~Node();
-                }
-            }
-        }
-    };
-
-    // Iter ////////////////////////////////////////////////////////////
-
-    struct fast_forward_tag {};
-
-    // generic iterator for both const_iterator and iterator.
-    template <bool IsConst>
-    // NOLINTNEXTLINE(hicpp-special-member-functions,cppcoreguidelines-special-member-functions)
-    class Iter {
-    private:
-        using NodePtr = typename std::conditional<IsConst, Node const*, Node*>::type;
-
-    public:
-        using difference_type = std::ptrdiff_t;
-        using value_type = typename Self::value_type;
-        using reference = typename std::conditional<IsConst, value_type const&, value_type&>::type;
-        using pointer = typename std::conditional<IsConst, value_type const*, value_type*>::type;
-        using iterator_category = std::forward_iterator_tag;
-
-        // default constructed iterator can be compared to itself, but WON'T return true when
-        // compared to end().
-        Iter() = default;
-
-        // Rule of zero: nothing specified. The conversion constructor is only enabled for
-        // iterator to const_iterator, so it doesn't accidentally work as a copy ctor.
-
-        // Conversion constructor from iterator to const_iterator.
-        template <bool OtherIsConst,
-                  typename = typename std::enable_if<IsConst && !OtherIsConst>::type>
-        // NOLINTNEXTLINE(hicpp-explicit-conversions)
-        Iter(Iter<OtherIsConst> const& other) noexcept
-            : mKeyVals(other.mKeyVals)
-            , mInfo(other.mInfo) {}
-
-        Iter(NodePtr valPtr, uint8_t const* infoPtr) noexcept
-            : mKeyVals(valPtr)
-            , mInfo(infoPtr) {}
-
-        Iter(NodePtr valPtr, uint8_t const* infoPtr,
-             fast_forward_tag ROBIN_HOOD_UNUSED(tag) /*unused*/) noexcept
-            : mKeyVals(valPtr)
-            , mInfo(infoPtr) {
-            fastForward();
-        }
-
-        template <bool OtherIsConst,
-                  typename = typename std::enable_if<IsConst && !OtherIsConst>::type>
-        Iter& operator=(Iter<OtherIsConst> const& other) noexcept {
-            mKeyVals = other.mKeyVals;
-            mInfo = other.mInfo;
-            return *this;
-        }
-
-        // prefix increment. Undefined behavior if we are at end()!
-        Iter& operator++() noexcept {
-            mInfo++;
-            mKeyVals++;
-            fastForward();
-            return *this;
-        }
-
-        Iter operator++(int) noexcept {
-            Iter tmp = *this;
-            ++(*this);
-            return tmp;
-        }
-
-        reference operator*() const {
-            return **mKeyVals;
-        }
-
-        pointer operator->() const {
-            return &**mKeyVals;
-        }
-
-        template <bool O>
-        bool operator==(Iter<O> const& o) const noexcept {
-            return mKeyVals == o.mKeyVals;
-        }
-
-        template <bool O>
-        bool operator!=(Iter<O> const& o) const noexcept {
-            return mKeyVals != o.mKeyVals;
-        }
-
-    private:
-        // fast forward to the next non-free info byte
-        // I've tried a few variants that don't depend on intrinsics, but unfortunately they are
-        // quite a bit slower than this one. So I've reverted that change again. See map_benchmark.
-        void fastForward() noexcept {
-            size_t n = 0;
-            while (0U == (n = detail::unaligned_load<size_t>(mInfo))) {
-                mInfo += sizeof(size_t);
-                mKeyVals += sizeof(size_t);
-            }
-#if defined(ROBIN_HOOD_DISABLE_INTRINSICS)
-            // we know for certain that within the next 8 bytes we'll find a non-zero one.
-            if (ROBIN_HOOD_UNLIKELY(0U == detail::unaligned_load<uint32_t>(mInfo))) {
-                mInfo += 4;
-                mKeyVals += 4;
-            }
-            if (ROBIN_HOOD_UNLIKELY(0U == detail::unaligned_load<uint16_t>(mInfo))) {
-                mInfo += 2;
-                mKeyVals += 2;
-            }
-            if (ROBIN_HOOD_UNLIKELY(0U == *mInfo)) {
-                mInfo += 1;
-                mKeyVals += 1;
-            }
-#else
-#    if ROBIN_HOOD(LITTLE_ENDIAN)
-            auto inc = ROBIN_HOOD_COUNT_TRAILING_ZEROES(n) / 8;
-#    else
-            auto inc = ROBIN_HOOD_COUNT_LEADING_ZEROES(n) / 8;
-#    endif
-            mInfo += inc;
-            mKeyVals += inc;
-#endif
-        }
-
-        friend class Table<IsFlat, MaxLoadFactor100, key_type, mapped_type, hasher, key_equal>;
-        NodePtr mKeyVals{nullptr};
-        uint8_t const* mInfo{nullptr};
-    };
-
-    ////////////////////////////////////////////////////////////////////
-
-    // highly performance relevant code.
-    // Lower bits are used for indexing into the array (2^n size)
-    // The upper 1-5 bits need to be a reasonable good hash, to save comparisons.
-    template <typename HashKey>
-    void keyToIdx(HashKey&& key, size_t* idx, InfoType* info) const {
-        // for a user-specified hash that is *not* robin_hood::hash, apply robin_hood::hash as
-        // an additional mixing step. This serves as a bad hash prevention, if the given data is
-        // badly mixed.
-        using Mix =
-            typename std::conditional<std::is_same<::robin_hood::hash<key_type>, hasher>::value,
-                                      ::robin_hood::detail::identity_hash<size_t>,
-                                      ::robin_hood::hash<size_t>>::type;
-
-        // the lower InitialInfoNumBits are reserved for info.
-        auto h = Mix{}(WHash::operator()(key));
-        *info = mInfoInc + static_cast<InfoType>((h & InfoMask) >> mInfoHashShift);
-        *idx = (h >> InitialInfoNumBits) & mMask;
-    }
-
-    // forwards the index by one, wrapping around at the end
-    void next(InfoType* info, size_t* idx) const noexcept {
-        *idx = *idx + 1;
-        *info += mInfoInc;
-    }
-
-    void nextWhileLess(InfoType* info, size_t* idx) const noexcept {
-        // unrolling this by hand did not bring any speedups.
-        while (*info < mInfo[*idx]) {
-            next(info, idx);
-        }
-    }
-
-    // Shift everything up by one element. Tries to move stuff around.
-    void
-    shiftUp(size_t startIdx,
-            size_t const insertion_idx) noexcept(std::is_nothrow_move_assignable<Node>::value) {
-        auto idx = startIdx;
-        ::new (static_cast<void*>(mKeyVals + idx)) Node(std::move(mKeyVals[idx - 1]));
-        while (--idx != insertion_idx) {
-            mKeyVals[idx] = std::move(mKeyVals[idx - 1]);
-        }
-
-        idx = startIdx;
-        while (idx != insertion_idx) {
-            ROBIN_HOOD_COUNT(shiftUp)
-            mInfo[idx] = static_cast<uint8_t>(mInfo[idx - 1] + mInfoInc);
-            if (ROBIN_HOOD_UNLIKELY(mInfo[idx] + mInfoInc > 0xFF)) {
-                mMaxNumElementsAllowed = 0;
-            }
-            --idx;
-        }
-    }
-
-    void shiftDown(size_t idx) noexcept(std::is_nothrow_move_assignable<Node>::value) {
-        // until we find one that is either empty or has zero offset.
-        // TODO(martinus) we don't need to move everything, just the last one for the same
-        // bucket.
-        mKeyVals[idx].destroy(*this);
-
-        // until we find one that is either empty or has zero offset.
-        while (mInfo[idx + 1] >= 2 * mInfoInc) {
-            ROBIN_HOOD_COUNT(shiftDown)
-            mInfo[idx] = static_cast<uint8_t>(mInfo[idx + 1] - mInfoInc);
-            mKeyVals[idx] = std::move(mKeyVals[idx + 1]);
-            ++idx;
-        }
-
-        mInfo[idx] = 0;
-        // don't destroy, we've moved it
-        // mKeyVals[idx].destroy(*this);
-        mKeyVals[idx].~Node();
-    }
-
-    // copy of find(), except that it returns iterator instead of const_iterator.
-    template <typename Other>
-    ROBIN_HOOD(NODISCARD)
-    size_t findIdx(Other const& key) const {
-        size_t idx{};
-        InfoType info{};
-        keyToIdx(key, &idx, &info);
-
-        do {
-            // unrolling this twice gives a bit of a speedup. More unrolling did not help.
-            if (info == mInfo[idx] &&
-                ROBIN_HOOD_LIKELY(WKeyEqual::operator()(key, mKeyVals[idx].getFirst()))) {
-                return idx;
-            }
-            next(&info, &idx);
-            if (info == mInfo[idx] &&
-                ROBIN_HOOD_LIKELY(WKeyEqual::operator()(key, mKeyVals[idx].getFirst()))) {
-                return idx;
-            }
-            next(&info, &idx);
-        } while (info <= mInfo[idx]);
-
-        // nothing found!
-        return mMask == 0 ? 0
-                          : static_cast<size_t>(std::distance(
-                                mKeyVals, reinterpret_cast_no_cast_align_warning<Node*>(mInfo)));
-    }
-
-    void cloneData(const Table& o) {
-        Cloner<Table, IsFlat && ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(Node)>()(o, *this);
-    }
-
-    // inserts a keyval that is guaranteed to be new, e.g. when the hashmap is resized.
-    // @return index where the element was created
-    size_t insert_move(Node&& keyval) {
-        // we don't retry, fail if overflowing
-        // don't need to check max num elements
-        if (0 == mMaxNumElementsAllowed && !try_increase_info()) {
-            throwOverflowError(); // impossible to reach LCOV_EXCL_LINE
-        }
-
-        size_t idx{};
-        InfoType info{};
-        keyToIdx(keyval.getFirst(), &idx, &info);
-
-        // skip forward. Use <= because we are certain that the element is not there.
-        while (info <= mInfo[idx]) {
-            idx = idx + 1;
-            info += mInfoInc;
-        }
-
-        // key not found, so we are now exactly where we want to insert it.
-        auto const insertion_idx = idx;
-        auto const insertion_info = static_cast<uint8_t>(info);
-        if (ROBIN_HOOD_UNLIKELY(insertion_info + mInfoInc > 0xFF)) {
-            mMaxNumElementsAllowed = 0;
-        }
-
-        // find an empty spot
-        while (0 != mInfo[idx]) {
-            next(&info, &idx);
-        }
-
-        auto& l = mKeyVals[insertion_idx];
-        if (idx == insertion_idx) {
-            ::new (static_cast<void*>(&l)) Node(std::move(keyval));
-        } else {
-            shiftUp(idx, insertion_idx);
-            l = std::move(keyval);
-        }
-
-        // put at empty spot
-        mInfo[insertion_idx] = insertion_info;
-
-        ++mNumElements;
-        return insertion_idx;
-    }
-
-public:
-    using iterator = Iter<false>;
-    using const_iterator = Iter<true>;
-
-    Table() noexcept(noexcept(Hash()) && noexcept(KeyEqual()))
-        : WHash()
-        , WKeyEqual() {
-        ROBIN_HOOD_TRACE(this)
-    }
-
-    // Creates an empty hash map. Nothing is allocated yet, this happens at the first insert.
-    // This tremendously speeds up ctor & dtor of a map that never receives an element. The
-    // penalty is payed at the first insert, and not before. Lookup of this empty map works
-    // because everybody points to DummyInfoByte::b. parameter bucket_count is dictated by the
-    // standard, but we can ignore it.
-    explicit Table(
-        size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/, const Hash& h = Hash{},
-        const KeyEqual& equal = KeyEqual{}) noexcept(noexcept(Hash(h)) && noexcept(KeyEqual(equal)))
-        : WHash(h)
-        , WKeyEqual(equal) {
-        ROBIN_HOOD_TRACE(this)
-    }
-
-    template <typename Iter>
-    Table(Iter first, Iter last, size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/ = 0,
-          const Hash& h = Hash{}, const KeyEqual& equal = KeyEqual{})
-        : WHash(h)
-        , WKeyEqual(equal) {
-        ROBIN_HOOD_TRACE(this)
-        insert(first, last);
-    }
-
-    Table(std::initializer_list<value_type> initlist,
-          size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/ = 0, const Hash& h = Hash{},
-          const KeyEqual& equal = KeyEqual{})
-        : WHash(h)
-        , WKeyEqual(equal) {
-        ROBIN_HOOD_TRACE(this)
-        insert(initlist.begin(), initlist.end());
-    }
-
-    Table(Table&& o) noexcept
-        : WHash(std::move(static_cast<WHash&>(o)))
-        , WKeyEqual(std::move(static_cast<WKeyEqual&>(o)))
-        , DataPool(std::move(static_cast<DataPool&>(o))) {
-        ROBIN_HOOD_TRACE(this)
-        if (o.mMask) {
-            mKeyVals = std::move(o.mKeyVals);
-            mInfo = std::move(o.mInfo);
-            mNumElements = std::move(o.mNumElements);
-            mMask = std::move(o.mMask);
-            mMaxNumElementsAllowed = std::move(o.mMaxNumElementsAllowed);
-            mInfoInc = std::move(o.mInfoInc);
-            mInfoHashShift = std::move(o.mInfoHashShift);
-            // set other's mask to 0 so its destructor won't do anything
-            o.init();
-        }
-    }
-
-    Table& operator=(Table&& o) noexcept {
-        ROBIN_HOOD_TRACE(this)
-        if (&o != this) {
-            if (o.mMask) {
-                // only move stuff if the other map actually has some data
-                destroy();
-                mKeyVals = std::move(o.mKeyVals);
-                mInfo = std::move(o.mInfo);
-                mNumElements = std::move(o.mNumElements);
-                mMask = std::move(o.mMask);
-                mMaxNumElementsAllowed = std::move(o.mMaxNumElementsAllowed);
-                mInfoInc = std::move(o.mInfoInc);
-                mInfoHashShift = std::move(o.mInfoHashShift);
-                WHash::operator=(std::move(static_cast<WHash&>(o)));
-                WKeyEqual::operator=(std::move(static_cast<WKeyEqual&>(o)));
-                DataPool::operator=(std::move(static_cast<DataPool&>(o)));
-
-                o.init();
-
-            } else {
-                // nothing in the other map => just clear us.
-                clear();
-            }
-        }
-        return *this;
-    }
-
-    Table(const Table& o)
-        : WHash(static_cast<const WHash&>(o))
-        , WKeyEqual(static_cast<const WKeyEqual&>(o))
-        , DataPool(static_cast<const DataPool&>(o)) {
-        ROBIN_HOOD_TRACE(this)
-        if (!o.empty()) {
-            // not empty: create an exact copy. it is also possible to just iterate through all
-            // elements and insert them, but copying is probably faster.
-
-            auto const numElementsWithBuffer = calcNumElementsWithBuffer(o.mMask + 1);
-            auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer);
-
-            ROBIN_HOOD_LOG("std::malloc " << numBytesTotal << " = calcNumBytesTotal("
-                                          << numElementsWithBuffer << ")")
-            mKeyVals = static_cast<Node*>(
-                detail::assertNotNull<std::bad_alloc>(std::malloc(numBytesTotal)));
-            // no need for calloc because clonData does memcpy
-            mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer);
-            mNumElements = o.mNumElements;
-            mMask = o.mMask;
-            mMaxNumElementsAllowed = o.mMaxNumElementsAllowed;
-            mInfoInc = o.mInfoInc;
-            mInfoHashShift = o.mInfoHashShift;
-            cloneData(o);
-        }
-    }
-
-    // Creates a copy of the given map. Copy constructor of each entry is used.
-    // Not sure why clang-tidy thinks this doesn't handle self assignment, it does
-    // NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp)
-    Table& operator=(Table const& o) {
-        ROBIN_HOOD_TRACE(this)
-        if (&o == this) {
-            // prevent assigning of itself
-            return *this;
-        }
-
-        // we keep using the old allocator and not assign the new one, because we want to keep
-        // the memory available. when it is the same size.
-        if (o.empty()) {
-            if (0 == mMask) {
-                // nothing to do, we are empty too
-                return *this;
-            }
-
-            // not empty: destroy what we have there
-            // clear also resets mInfo to 0, that's sometimes not necessary.
-            destroy();
-            init();
-            WHash::operator=(static_cast<const WHash&>(o));
-            WKeyEqual::operator=(static_cast<const WKeyEqual&>(o));
-            DataPool::operator=(static_cast<DataPool const&>(o));
-
-            return *this;
-        }
-
-        // clean up old stuff
-        Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{}.nodes(*this);
-
-        if (mMask != o.mMask) {
-            // no luck: we don't have the same array size allocated, so we need to realloc.
-            if (0 != mMask) {
-                // only deallocate if we actually have data!
-                ROBIN_HOOD_LOG("std::free")
-                std::free(mKeyVals);
-            }
-
-            auto const numElementsWithBuffer = calcNumElementsWithBuffer(o.mMask + 1);
-            auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer);
-            ROBIN_HOOD_LOG("std::malloc " << numBytesTotal << " = calcNumBytesTotal("
-                                          << numElementsWithBuffer << ")")
-            mKeyVals = static_cast<Node*>(
-                detail::assertNotNull<std::bad_alloc>(std::malloc(numBytesTotal)));
-
-            // no need for calloc here because cloneData performs a memcpy.
-            mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer);
-            // sentinel is set in cloneData
-        }
-        WHash::operator=(static_cast<const WHash&>(o));
-        WKeyEqual::operator=(static_cast<const WKeyEqual&>(o));
-        DataPool::operator=(static_cast<DataPool const&>(o));
-        mNumElements = o.mNumElements;
-        mMask = o.mMask;
-        mMaxNumElementsAllowed = o.mMaxNumElementsAllowed;
-        mInfoInc = o.mInfoInc;
-        mInfoHashShift = o.mInfoHashShift;
-        cloneData(o);
-
-        return *this;
-    }
-
-    // Swaps everything between the two maps.
-    void swap(Table& o) {
-        ROBIN_HOOD_TRACE(this)
-        using std::swap;
-        swap(o, *this);
-    }
-
-    // Clears all data, without resizing.
-    void clear() {
-        ROBIN_HOOD_TRACE(this)
-        if (empty()) {
-            // don't do anything! also important because we don't want to write to
-            // DummyInfoByte::b, even though we would just write 0 to it.
-            return;
-        }
-
-        Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{}.nodes(*this);
-
-        auto const numElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1);
-        // clear everything, then set the sentinel again
-        uint8_t const z = 0;
-        std::fill(mInfo, mInfo + calcNumBytesInfo(numElementsWithBuffer), z);
-        mInfo[numElementsWithBuffer] = 1;
-
-        mInfoInc = InitialInfoInc;
-        mInfoHashShift = InitialInfoHashShift;
-    }
-
-    // Destroys the map and all it's contents.
-    ~Table() {
-        ROBIN_HOOD_TRACE(this)
-        destroy();
-    }
-
-    // Checks if both tables contain the same entries. Order is irrelevant.
-    bool operator==(const Table& other) const {
-        ROBIN_HOOD_TRACE(this)
-        if (other.size() != size()) {
-            return false;
-        }
-        for (auto const& otherEntry : other) {
-            if (!has(otherEntry)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-    bool operator!=(const Table& other) const {
-        ROBIN_HOOD_TRACE(this)
-        return !operator==(other);
-    }
-
-    template <typename Q = mapped_type>
-    typename std::enable_if<!std::is_void<Q>::value, Q&>::type operator[](const key_type& key) {
-        ROBIN_HOOD_TRACE(this)
-        return doCreateByKey(key);
-    }
-
-    template <typename Q = mapped_type>
-    typename std::enable_if<!std::is_void<Q>::value, Q&>::type operator[](key_type&& key) {
-        ROBIN_HOOD_TRACE(this)
-        return doCreateByKey(std::move(key));
-    }
-
-    template <typename Iter>
-    void insert(Iter first, Iter last) {
-        for (; first != last; ++first) {
-            // value_type ctor needed because this might be called with std::pair's
-            insert(value_type(*first));
-        }
-    }
-
-    template <typename... Args>
-    std::pair<iterator, bool> emplace(Args&&... args) {
-        ROBIN_HOOD_TRACE(this)
-        Node n{*this, std::forward<Args>(args)...};
-        auto r = doInsert(std::move(n));
-        if (!r.second) {
-            // insertion not possible: destroy node
-            // NOLINTNEXTLINE(bugprone-use-after-move)
-            n.destroy(*this);
-        }
-        return r;
-    }
-
-    template <typename... Args>
-    std::pair<iterator, bool> try_emplace(const key_type& key, Args&&... args) {
-        return try_emplace_impl(key, std::forward<Args>(args)...);
-    }
-
-    template <typename... Args>
-    std::pair<iterator, bool> try_emplace(key_type&& key, Args&&... args) {
-        return try_emplace_impl(std::move(key), std::forward<Args>(args)...);
-    }
-
-    template <typename... Args>
-    std::pair<iterator, bool> try_emplace(const_iterator hint, const key_type& key,
-                                          Args&&... args) {
-        (void)hint;
-        return try_emplace_impl(key, std::forward<Args>(args)...);
-    }
-
-    template <typename... Args>
-    std::pair<iterator, bool> try_emplace(const_iterator hint, key_type&& key, Args&&... args) {
-        (void)hint;
-        return try_emplace_impl(std::move(key), std::forward<Args>(args)...);
-    }
-
-    template <typename Mapped>
-    std::pair<iterator, bool> insert_or_assign(const key_type& key, Mapped&& obj) {
-        return insert_or_assign_impl(key, std::forward<Mapped>(obj));
-    }
-
-    template <typename Mapped>
-    std::pair<iterator, bool> insert_or_assign(key_type&& key, Mapped&& obj) {
-        return insert_or_assign_impl(std::move(key), std::forward<Mapped>(obj));
-    }
-
-    template <typename Mapped>
-    std::pair<iterator, bool> insert_or_assign(const_iterator hint, const key_type& key,
-                                               Mapped&& obj) {
-        (void)hint;
-        return insert_or_assign_impl(key, std::forward<Mapped>(obj));
-    }
-
-    template <typename Mapped>
-    std::pair<iterator, bool> insert_or_assign(const_iterator hint, key_type&& key, Mapped&& obj) {
-        (void)hint;
-        return insert_or_assign_impl(std::move(key), std::forward<Mapped>(obj));
-    }
-
-    std::pair<iterator, bool> insert(const value_type& keyval) {
-        ROBIN_HOOD_TRACE(this)
-        return doInsert(keyval);
-    }
-
-    std::pair<iterator, bool> insert(value_type&& keyval) {
-        return doInsert(std::move(keyval));
-    }
-
-    // Returns 1 if key is found, 0 otherwise.
-    size_t count(const key_type& key) const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        auto kv = mKeyVals + findIdx(key);
-        if (kv != reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) {
-            return 1;
-        }
-        return 0;
-    }
-
-    template <typename OtherKey, typename Self_ = Self>
-    // NOLINTNEXTLINE(modernize-use-nodiscard)
-    typename std::enable_if<Self_::is_transparent, size_t>::type count(const OtherKey& key) const {
-        ROBIN_HOOD_TRACE(this)
-        auto kv = mKeyVals + findIdx(key);
-        if (kv != reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) {
-            return 1;
-        }
-        return 0;
-    }
-
-    bool contains(const key_type& key) const { // NOLINT(modernize-use-nodiscard)
-        return 1U == count(key);
-    }
-
-    template <typename OtherKey, typename Self_ = Self>
-    // NOLINTNEXTLINE(modernize-use-nodiscard)
-    typename std::enable_if<Self_::is_transparent, bool>::type contains(const OtherKey& key) const {
-        return 1U == count(key);
-    }
-
-    // Returns a reference to the value found for key.
-    // Throws std::out_of_range if element cannot be found
-    template <typename Q = mapped_type>
-    // NOLINTNEXTLINE(modernize-use-nodiscard)
-    typename std::enable_if<!std::is_void<Q>::value, Q&>::type at(key_type const& key) {
-        ROBIN_HOOD_TRACE(this)
-        auto kv = mKeyVals + findIdx(key);
-        if (kv == reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) {
-            doThrow<std::out_of_range>("key not found");
-        }
-        return kv->getSecond();
-    }
-
-    // Returns a reference to the value found for key.
-    // Throws std::out_of_range if element cannot be found
-    template <typename Q = mapped_type>
-    // NOLINTNEXTLINE(modernize-use-nodiscard)
-    typename std::enable_if<!std::is_void<Q>::value, Q const&>::type at(key_type const& key) const {
-        ROBIN_HOOD_TRACE(this)
-        auto kv = mKeyVals + findIdx(key);
-        if (kv == reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) {
-            doThrow<std::out_of_range>("key not found");
-        }
-        return kv->getSecond();
-    }
-
-    const_iterator find(const key_type& key) const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return const_iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    template <typename OtherKey>
-    const_iterator find(const OtherKey& key, is_transparent_tag /*unused*/) const {
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return const_iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    template <typename OtherKey, typename Self_ = Self>
-    typename std::enable_if<Self_::is_transparent, // NOLINT(modernize-use-nodiscard)
-                            const_iterator>::type  // NOLINT(modernize-use-nodiscard)
-    find(const OtherKey& key) const {              // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return const_iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    iterator find(const key_type& key) {
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    template <typename OtherKey>
-    iterator find(const OtherKey& key, is_transparent_tag /*unused*/) {
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    template <typename OtherKey, typename Self_ = Self>
-    typename std::enable_if<Self_::is_transparent, iterator>::type find(const OtherKey& key) {
-        ROBIN_HOOD_TRACE(this)
-        const size_t idx = findIdx(key);
-        return iterator{mKeyVals + idx, mInfo + idx};
-    }
-
-    iterator begin() {
-        ROBIN_HOOD_TRACE(this)
-        if (empty()) {
-            return end();
-        }
-        return iterator(mKeyVals, mInfo, fast_forward_tag{});
-    }
-    const_iterator begin() const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return cbegin();
-    }
-    const_iterator cbegin() const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        if (empty()) {
-            return cend();
-        }
-        return const_iterator(mKeyVals, mInfo, fast_forward_tag{});
-    }
-
-    iterator end() {
-        ROBIN_HOOD_TRACE(this)
-        // no need to supply valid info pointer: end() must not be dereferenced, and only node
-        // pointer is compared.
-        return iterator{reinterpret_cast_no_cast_align_warning<Node*>(mInfo), nullptr};
-    }
-    const_iterator end() const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return cend();
-    }
-    const_iterator cend() const { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return const_iterator{reinterpret_cast_no_cast_align_warning<Node*>(mInfo), nullptr};
-    }
-
-    iterator erase(const_iterator pos) {
-        ROBIN_HOOD_TRACE(this)
-        // its safe to perform const cast here
-        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
-        return erase(iterator{const_cast<Node*>(pos.mKeyVals), const_cast<uint8_t*>(pos.mInfo)});
-    }
-
-    // Erases element at pos, returns iterator to the next element.
-    iterator erase(iterator pos) {
-        ROBIN_HOOD_TRACE(this)
-        // we assume that pos always points to a valid entry, and not end().
-        auto const idx = static_cast<size_t>(pos.mKeyVals - mKeyVals);
-
-        shiftDown(idx);
-        --mNumElements;
-
-        if (*pos.mInfo) {
-            // we've backward shifted, return this again
-            return pos;
-        }
-
-        // no backward shift, return next element
-        return ++pos;
-    }
-
-    size_t erase(const key_type& key) {
-        ROBIN_HOOD_TRACE(this)
-        size_t idx{};
-        InfoType info{};
-        keyToIdx(key, &idx, &info);
-
-        // check while info matches with the source idx
-        do {
-            if (info == mInfo[idx] && WKeyEqual::operator()(key, mKeyVals[idx].getFirst())) {
-                shiftDown(idx);
-                --mNumElements;
-                return 1;
-            }
-            next(&info, &idx);
-        } while (info <= mInfo[idx]);
-
-        // nothing found to delete
-        return 0;
-    }
-
-    // reserves space for the specified number of elements. Makes sure the old data fits.
-    // exactly the same as reserve(c).
-    void rehash(size_t c) {
-        // forces a reserve
-        reserve(c, true);
-    }
-
-    // reserves space for the specified number of elements. Makes sure the old data fits.
-    // Exactly the same as rehash(c). Use rehash(0) to shrink to fit.
-    void reserve(size_t c) {
-        // reserve, but don't force rehash
-        reserve(c, false);
-    }
-
-    size_type size() const noexcept { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return mNumElements;
-    }
-
-    size_type max_size() const noexcept { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return static_cast<size_type>(-1);
-    }
-
-    ROBIN_HOOD(NODISCARD) bool empty() const noexcept {
-        ROBIN_HOOD_TRACE(this)
-        return 0 == mNumElements;
-    }
-
-    float max_load_factor() const noexcept { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return MaxLoadFactor100 / 100.0F;
-    }
-
-    // Average number of elements per bucket. Since we allow only 1 per bucket
-    float load_factor() const noexcept { // NOLINT(modernize-use-nodiscard)
-        ROBIN_HOOD_TRACE(this)
-        return static_cast<float>(size()) / static_cast<float>(mMask + 1);
-    }
-
-    ROBIN_HOOD(NODISCARD) size_t mask() const noexcept {
-        ROBIN_HOOD_TRACE(this)
-        return mMask;
-    }
-
-    ROBIN_HOOD(NODISCARD) size_t calcMaxNumElementsAllowed(size_t maxElements) const noexcept {
-        if (ROBIN_HOOD_LIKELY(maxElements <= (std::numeric_limits<size_t>::max)() / 100)) {
-            return maxElements * MaxLoadFactor100 / 100;
-        }
-
-        // we might be a bit inprecise, but since maxElements is quite large that doesn't matter
-        return (maxElements / 100) * MaxLoadFactor100;
-    }
-
-    ROBIN_HOOD(NODISCARD) size_t calcNumBytesInfo(size_t numElements) const noexcept {
-        // we add a uint64_t, which houses the sentinel (first byte) and padding so we can load
-        // 64bit types.
-        return numElements + sizeof(uint64_t);
-    }
-
-    ROBIN_HOOD(NODISCARD)
-    size_t calcNumElementsWithBuffer(size_t numElements) const noexcept {
-        auto maxNumElementsAllowed = calcMaxNumElementsAllowed(numElements);
-        return numElements + (std::min)(maxNumElementsAllowed, (static_cast<size_t>(0xFF)));
-    }
-
-    // calculation only allowed for 2^n values
-    ROBIN_HOOD(NODISCARD) size_t calcNumBytesTotal(size_t numElements) const {
-#if ROBIN_HOOD(BITNESS) == 64
-        return numElements * sizeof(Node) + calcNumBytesInfo(numElements);
-#else
-        // make sure we're doing 64bit operations, so we are at least safe against 32bit overflows.
-        auto const ne = static_cast<uint64_t>(numElements);
-        auto const s = static_cast<uint64_t>(sizeof(Node));
-        auto const infos = static_cast<uint64_t>(calcNumBytesInfo(numElements));
-
-        auto const total64 = ne * s + infos;
-        auto const total = static_cast<size_t>(total64);
-
-        if (ROBIN_HOOD_UNLIKELY(static_cast<uint64_t>(total) != total64)) {
-            throwOverflowError();
-        }
-        return total;
-#endif
-    }
-
-private:
-    template <typename Q = mapped_type>
-    ROBIN_HOOD(NODISCARD)
-    typename std::enable_if<!std::is_void<Q>::value, bool>::type has(const value_type& e) const {
-        ROBIN_HOOD_TRACE(this)
-        auto it = find(e.first);
-        return it != end() && it->second == e.second;
-    }
-
-    template <typename Q = mapped_type>
-    ROBIN_HOOD(NODISCARD)
-    typename std::enable_if<std::is_void<Q>::value, bool>::type has(const value_type& e) const {
-        ROBIN_HOOD_TRACE(this)
-        return find(e) != end();
-    }
-
-    void reserve(size_t c, bool forceRehash) {
-        ROBIN_HOOD_TRACE(this)
-        auto const minElementsAllowed = (std::max)(c, mNumElements);
-        auto newSize = InitialNumElements;
-        while (calcMaxNumElementsAllowed(newSize) < minElementsAllowed && newSize != 0) {
-            newSize *= 2;
-        }
-        if (ROBIN_HOOD_UNLIKELY(newSize == 0)) {
-            throwOverflowError();
-        }
-
-        ROBIN_HOOD_LOG("newSize > mMask + 1: " << newSize << " > " << mMask << " + 1")
-
-        // only actually do anything when the new size is bigger than the old one. This prevents to
-        // continuously allocate for each reserve() call.
-        if (forceRehash || newSize > mMask + 1) {
-            rehashPowerOfTwo(newSize);
-        }
-    }
-
-    // reserves space for at least the specified number of elements.
-    // only works if numBuckets if power of two
-    void rehashPowerOfTwo(size_t numBuckets) {
-        ROBIN_HOOD_TRACE(this)
-
-        Node* const oldKeyVals = mKeyVals;
-        uint8_t const* const oldInfo = mInfo;
-
-        const size_t oldMaxElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1);
-
-        // resize operation: move stuff
-        init_data(numBuckets);
-        if (oldMaxElementsWithBuffer > 1) {
-            for (size_t i = 0; i < oldMaxElementsWithBuffer; ++i) {
-                if (oldInfo[i] != 0) {
-                    insert_move(std::move(oldKeyVals[i]));
-                    // destroy the node but DON'T destroy the data.
-                    oldKeyVals[i].~Node();
-                }
-            }
-
-            // this check is not necessary as it's guarded by the previous if, but it helps silence
-            // g++'s overeager "attempt to free a non-heap object 'map'
-            // [-Werror=free-nonheap-object]" warning.
-            if (oldKeyVals != reinterpret_cast_no_cast_align_warning<Node*>(&mMask)) {
-                // don't destroy old data: put it into the pool instead
-                DataPool::addOrFree(oldKeyVals, calcNumBytesTotal(oldMaxElementsWithBuffer));
-            }
-        }
-    }
-
-    ROBIN_HOOD(NOINLINE) void throwOverflowError() const {
-#if ROBIN_HOOD(HAS_EXCEPTIONS)
-        throw std::overflow_error("robin_hood::map overflow");
-#else
-        abort();
-#endif
-    }
-
-    template <typename OtherKey, typename... Args>
-    std::pair<iterator, bool> try_emplace_impl(OtherKey&& key, Args&&... args) {
-        ROBIN_HOOD_TRACE(this)
-        auto it = find(key);
-        if (it == end()) {
-            return emplace(std::piecewise_construct,
-                           std::forward_as_tuple(std::forward<OtherKey>(key)),
-                           std::forward_as_tuple(std::forward<Args>(args)...));
-        }
-        return {it, false};
-    }
-
-    template <typename OtherKey, typename Mapped>
-    std::pair<iterator, bool> insert_or_assign_impl(OtherKey&& key, Mapped&& obj) {
-        ROBIN_HOOD_TRACE(this)
-        auto it = find(key);
-        if (it == end()) {
-            return emplace(std::forward<OtherKey>(key), std::forward<Mapped>(obj));
-        }
-        it->second = std::forward<Mapped>(obj);
-        return {it, false};
-    }
-
-    void init_data(size_t max_elements) {
-        mNumElements = 0;
-        mMask = max_elements - 1;
-        mMaxNumElementsAllowed = calcMaxNumElementsAllowed(max_elements);
-
-        auto const numElementsWithBuffer = calcNumElementsWithBuffer(max_elements);
-
-        // calloc also zeroes everything
-        auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer);
-        ROBIN_HOOD_LOG("std::calloc " << numBytesTotal << " = calcNumBytesTotal("
-                                      << numElementsWithBuffer << ")")
-        mKeyVals = reinterpret_cast<Node*>(
-            detail::assertNotNull<std::bad_alloc>(std::calloc(1, numBytesTotal)));
-        mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer);
-
-        // set sentinel
-        mInfo[numElementsWithBuffer] = 1;
-
-        mInfoInc = InitialInfoInc;
-        mInfoHashShift = InitialInfoHashShift;
-    }
-
-    template <typename Arg, typename Q = mapped_type>
-    typename std::enable_if<!std::is_void<Q>::value, Q&>::type doCreateByKey(Arg&& key) {
-        while (true) {
-            size_t idx{};
-            InfoType info{};
-            keyToIdx(key, &idx, &info);
-            nextWhileLess(&info, &idx);
-
-            // while we potentially have a match. Can't do a do-while here because when mInfo is
-            // 0 we don't want to skip forward
-            while (info == mInfo[idx]) {
-                if (WKeyEqual::operator()(key, mKeyVals[idx].getFirst())) {
-                    // key already exists, do not insert.
-                    return mKeyVals[idx].getSecond();
-                }
-                next(&info, &idx);
-            }
-
-            // unlikely that this evaluates to true
-            if (ROBIN_HOOD_UNLIKELY(mNumElements >= mMaxNumElementsAllowed)) {
-                increase_size();
-                continue;
-            }
-
-            // key not found, so we are now exactly where we want to insert it.
-            auto const insertion_idx = idx;
-            auto const insertion_info = info;
-            if (ROBIN_HOOD_UNLIKELY(insertion_info + mInfoInc > 0xFF)) {
-                mMaxNumElementsAllowed = 0;
-            }
-
-            // find an empty spot
-            while (0 != mInfo[idx]) {
-                next(&info, &idx);
-            }
-
-            auto& l = mKeyVals[insertion_idx];
-            if (idx == insertion_idx) {
-                // put at empty spot. This forwards all arguments into the node where the object
-                // is constructed exactly where it is needed.
-                ::new (static_cast<void*>(&l))
-                    Node(*this, std::piecewise_construct,
-                         std::forward_as_tuple(std::forward<Arg>(key)), std::forward_as_tuple());
-            } else {
-                shiftUp(idx, insertion_idx);
-                l = Node(*this, std::piecewise_construct,
-                         std::forward_as_tuple(std::forward<Arg>(key)), std::forward_as_tuple());
-            }
-
-            // mKeyVals[idx].getFirst() = std::move(key);
-            mInfo[insertion_idx] = static_cast<uint8_t>(insertion_info);
-
-            ++mNumElements;
-            return mKeyVals[insertion_idx].getSecond();
-        }
-    }
-
-    // This is exactly the same code as operator[], except for the return values
-    template <typename Arg>
-    std::pair<iterator, bool> doInsert(Arg&& keyval) {
-        while (true) {
-            size_t idx{};
-            InfoType info{};
-            keyToIdx(getFirstConst(keyval), &idx, &info);
-            nextWhileLess(&info, &idx);
-
-            // while we potentially have a match
-            while (info == mInfo[idx]) {
-                if (WKeyEqual::operator()(getFirstConst(keyval), mKeyVals[idx].getFirst())) {
-                    // key already exists, do NOT insert.
-                    // see http://en.cppreference.com/w/cpp/container/unordered_map/insert
-                    return std::make_pair<iterator, bool>(iterator(mKeyVals + idx, mInfo + idx),
-                                                          false);
-                }
-                next(&info, &idx);
-            }
-
-            // unlikely that this evaluates to true
-            if (ROBIN_HOOD_UNLIKELY(mNumElements >= mMaxNumElementsAllowed)) {
-                increase_size();
-                continue;
-            }
-
-            // key not found, so we are now exactly where we want to insert it.
-            auto const insertion_idx = idx;
-            auto const insertion_info = info;
-            if (ROBIN_HOOD_UNLIKELY(insertion_info + mInfoInc > 0xFF)) {
-                mMaxNumElementsAllowed = 0;
-            }
-
-            // find an empty spot
-            while (0 != mInfo[idx]) {
-                next(&info, &idx);
-            }
-
-            auto& l = mKeyVals[insertion_idx];
-            if (idx == insertion_idx) {
-                ::new (static_cast<void*>(&l)) Node(*this, std::forward<Arg>(keyval));
-            } else {
-                shiftUp(idx, insertion_idx);
-                l = Node(*this, std::forward<Arg>(keyval));
-            }
-
-            // put at empty spot
-            mInfo[insertion_idx] = static_cast<uint8_t>(insertion_info);
-
-            ++mNumElements;
-            return std::make_pair(iterator(mKeyVals + insertion_idx, mInfo + insertion_idx), true);
-        }
-    }
-
-    bool try_increase_info() {
-        ROBIN_HOOD_LOG("mInfoInc=" << mInfoInc << ", numElements=" << mNumElements
-                                   << ", maxNumElementsAllowed="
-                                   << calcMaxNumElementsAllowed(mMask + 1))
-        if (mInfoInc <= 2) {
-            // need to be > 2 so that shift works (otherwise undefined behavior!)
-            return false;
-        }
-        // we got space left, try to make info smaller
-        mInfoInc = static_cast<uint8_t>(mInfoInc >> 1U);
-
-        // remove one bit of the hash, leaving more space for the distance info.
-        // This is extremely fast because we can operate on 8 bytes at once.
-        ++mInfoHashShift;
-        auto const numElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1);
-
-        for (size_t i = 0; i < numElementsWithBuffer; i += 8) {
-            auto val = unaligned_load<uint64_t>(mInfo + i);
-            val = (val >> 1U) & UINT64_C(0x7f7f7f7f7f7f7f7f);
-            std::memcpy(mInfo + i, &val, sizeof(val));
-        }
-        // update sentinel, which might have been cleared out!
-        mInfo[numElementsWithBuffer] = 1;
-
-        mMaxNumElementsAllowed = calcMaxNumElementsAllowed(mMask + 1);
-        return true;
-    }
-
-    void increase_size() {
-        // nothing allocated yet? just allocate InitialNumElements
-        if (0 == mMask) {
-            init_data(InitialNumElements);
-            return;
-        }
-
-        auto const maxNumElementsAllowed = calcMaxNumElementsAllowed(mMask + 1);
-        if (mNumElements < maxNumElementsAllowed && try_increase_info()) {
-            return;
-        }
-
-        ROBIN_HOOD_LOG("mNumElements=" << mNumElements << ", maxNumElementsAllowed="
-                                       << maxNumElementsAllowed << ", load="
-                                       << (static_cast<double>(mNumElements) * 100.0 /
-                                           (static_cast<double>(mMask) + 1)))
-        // it seems we have a really bad hash function! don't try to resize again
-        if (mNumElements * 2 < calcMaxNumElementsAllowed(mMask + 1)) {
-            throwOverflowError();
-        }
-
-        rehashPowerOfTwo((mMask + 1) * 2);
-    }
-
-    void destroy() {
-        if (0 == mMask) {
-            // don't deallocate!
-            return;
-        }
-
-        Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{}
-            .nodesDoNotDeallocate(*this);
-
-        // This protection against not deleting mMask shouldn't be needed as it's sufficiently
-        // protected with the 0==mMask check, but I have this anyways because g++ 7 otherwise
-        // reports a compile error: attempt to free a non-heap object 'fm'
-        // [-Werror=free-nonheap-object]
-        if (mKeyVals != reinterpret_cast_no_cast_align_warning<Node*>(&mMask)) {
-            ROBIN_HOOD_LOG("std::free")
-            std::free(mKeyVals);
-        }
-    }
-
-    void init() noexcept {
-        mKeyVals = reinterpret_cast_no_cast_align_warning<Node*>(&mMask);
-        mInfo = reinterpret_cast<uint8_t*>(&mMask);
-        mNumElements = 0;
-        mMask = 0;
-        mMaxNumElementsAllowed = 0;
-        mInfoInc = InitialInfoInc;
-        mInfoHashShift = InitialInfoHashShift;
-    }
-
-    // members are sorted so no padding occurs
-    Node* mKeyVals = reinterpret_cast_no_cast_align_warning<Node*>(&mMask); // 8 byte  8
-    uint8_t* mInfo = reinterpret_cast<uint8_t*>(&mMask);                    // 8 byte 16
-    size_t mNumElements = 0;                                                // 8 byte 24
-    size_t mMask = 0;                                                       // 8 byte 32
-    size_t mMaxNumElementsAllowed = 0;                                      // 8 byte 40
-    InfoType mInfoInc = InitialInfoInc;                                     // 4 byte 44
-    InfoType mInfoHashShift = InitialInfoHashShift;                         // 4 byte 48
-                                                    // 16 byte 56 if NodeAllocator
-};
-
-} // namespace detail
-
-// map
-
-template <typename Key, typename T, typename Hash = hash<Key>,
-          typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80>
-using unordered_flat_map = detail::Table<true, MaxLoadFactor100, Key, T, Hash, KeyEqual>;
-
-template <typename Key, typename T, typename Hash = hash<Key>,
-          typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80>
-using unordered_node_map = detail::Table<false, MaxLoadFactor100, Key, T, Hash, KeyEqual>;
-
-template <typename Key, typename T, typename Hash = hash<Key>,
-          typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80>
-using unordered_map =
-    detail::Table<sizeof(robin_hood::pair<Key, T>) <= sizeof(size_t) * 6 &&
-                      std::is_nothrow_move_constructible<robin_hood::pair<Key, T>>::value &&
-                      std::is_nothrow_move_assignable<robin_hood::pair<Key, T>>::value,
-                  MaxLoadFactor100, Key, T, Hash, KeyEqual>;
-
-// set
-
-template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>,
-          size_t MaxLoadFactor100 = 80>
-using unordered_flat_set = detail::Table<true, MaxLoadFactor100, Key, void, Hash, KeyEqual>;
-
-template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>,
-          size_t MaxLoadFactor100 = 80>
-using unordered_node_set = detail::Table<false, MaxLoadFactor100, Key, void, Hash, KeyEqual>;
-
-template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>,
-          size_t MaxLoadFactor100 = 80>
-using unordered_set = detail::Table<sizeof(Key) <= sizeof(size_t) * 6 &&
-                                        std::is_nothrow_move_constructible<Key>::value &&
-                                        std::is_nothrow_move_assignable<Key>::value,
-                                    MaxLoadFactor100, Key, void, Hash, KeyEqual>;
-
-} // namespace robin_hood
-
-#endif
diff --git a/src/libmime/received.cxx b/src/libmime/received.cxx
index 691d7ca04..8e0609f39 100644
--- a/src/libmime/received.cxx
+++ b/src/libmime/received.cxx
@@ -879,7 +879,7 @@ TEST_SUITE("received") {
 TEST_CASE("parse received")
 {
 	using namespace std::string_view_literals;
-	using map_type = robin_hood::unordered_flat_map<std::string_view, std::string_view>;
+	using map_type = ankerl::unordered_dense::map<std::string_view, std::string_view>;
 	std::vector<std::pair<std::string_view, map_type>> cases{
 			// Simple received
 			{"from smtp11.mailtrack.pl (smtp11.mailtrack.pl [185.243.30.90])"sv,
diff --git a/src/libmime/received.hxx b/src/libmime/received.hxx
index 2edf628cc..a5d5e3fe6 100644
--- a/src/libmime/received.hxx
+++ b/src/libmime/received.hxx
@@ -24,7 +24,7 @@
 #include "mime_string.hxx"
 #include "libmime/email_addr.h"
 #include "libserver/task.h"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include <vector>
 #include <string_view>
 #include <utility>
@@ -179,7 +179,7 @@ struct received_header {
 	}
 
 	/* Unit tests helper */
-	static auto from_map(const robin_hood::unordered_flat_map<std::string_view, std::string_view> &map) -> received_header {
+	static auto from_map(const ankerl::unordered_dense::map<std::string_view, std::string_view> &map) -> received_header {
 		using namespace std::string_view_literals;
 		received_header rh;
 
@@ -202,9 +202,9 @@ struct received_header {
 		return rh;
 	}
 
-	auto as_map() const -> robin_hood::unordered_flat_map<std::string_view, std::string_view>
+	auto as_map() const -> ankerl::unordered_dense::map<std::string_view, std::string_view>
 	{
-		robin_hood::unordered_flat_map<std::string_view, std::string_view> map;
+		ankerl::unordered_dense::map<std::string_view, std::string_view> map;
 
 		if (!from_hostname.empty()) {
 			map["from_hostname"] = from_hostname.as_view();
diff --git a/src/libserver/composites/composites.cxx b/src/libserver/composites/composites.cxx
index 3b5b274a7..9779b4678 100644
--- a/src/libserver/composites/composites.cxx
+++ b/src/libserver/composites/composites.cxx
@@ -25,7 +25,7 @@
 #include <vector>
 #include <variant>
 #include "libutil/cxx/util.hxx"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 
 #include "composites_internal.hxx"
 
@@ -82,7 +82,7 @@ struct composites_data {
 	struct rspamd_task *task;
 	struct rspamd_composite *composite;
 	struct rspamd_scan_result *metric_res;
-	robin_hood::unordered_flat_map<std::string_view,
+	ankerl::unordered_dense::map<std::string_view,
 			std::vector<symbol_remove_data>> symbols_to_remove;
 	std::vector<bool> checked;
 
diff --git a/src/libserver/composites/composites_internal.hxx b/src/libserver/composites/composites_internal.hxx
index a12d5f9af..570cb4ea9 100644
--- a/src/libserver/composites/composites_internal.hxx
+++ b/src/libserver/composites/composites_internal.hxx
@@ -93,7 +93,7 @@ private:
 		return composite;
 	}
 
-	robin_hood::unordered_flat_map<std::string,
+	ankerl::unordered_dense::map<std::string,
 			std::shared_ptr<rspamd_composite>, rspamd::smart_str_hash, rspamd::smart_str_equal> composites;
 	/* Store all composites here, even if we have duplicates */
 	std::vector<std::shared_ptr<rspamd_composite>> all_composites;
diff --git a/src/libserver/composites/composites_manager.cxx b/src/libserver/composites/composites_manager.cxx
index bf56fe675..27fb170b9 100644
--- a/src/libserver/composites/composites_manager.cxx
+++ b/src/libserver/composites/composites_manager.cxx
@@ -17,7 +17,7 @@
 #include <memory>
 #include <vector>
 #include <cmath>
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 
 #include "composites.h"
 #include "composites_internal.hxx"
@@ -29,7 +29,7 @@ namespace rspamd::composites {
 static auto
 composite_policy_from_str(const std::string_view &inp) -> enum rspamd_composite_policy
 {
-	const static robin_hood::unordered_flat_map<std::string_view,
+	const static ankerl::unordered_dense::map<std::string_view,
 			enum rspamd_composite_policy> names{
 			{"remove",        rspamd_composite_policy::RSPAMD_COMPOSITE_POLICY_REMOVE_ALL},
 			{"remove_all",    rspamd_composite_policy::RSPAMD_COMPOSITE_POLICY_REMOVE_ALL},
diff --git a/src/libserver/css/css.cxx b/src/libserver/css/css.cxx
index 9e26eb42f..7de4ab307 100644
--- a/src/libserver/css/css.cxx
+++ b/src/libserver/css/css.cxx
@@ -15,7 +15,7 @@
  */
 
 #include "css.hxx"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "css_parser.hxx"
 #include "libserver/html/html_tag.hxx"
 #include "libserver/html/html_block.hxx"
@@ -34,7 +34,7 @@ public:
 	using sel_shared_hash = smart_ptr_hash<css_selector>;
 	using sel_shared_eq = smart_ptr_equal<css_selector>;
 	using selector_ptr = std::unique_ptr<css_selector>;
-	using selectors_hash = robin_hood::unordered_flat_map<selector_ptr, css_declarations_block_ptr,
+	using selectors_hash = ankerl::unordered_dense::map<selector_ptr, css_declarations_block_ptr,
 			sel_shared_hash, sel_shared_eq>;
 	using universal_selector_t = std::pair<selector_ptr, css_declarations_block_ptr>;
 	selectors_hash tags_selector;
diff --git a/src/libserver/css/css_colors_list.hxx b/src/libserver/css/css_colors_list.hxx
index b1fc5d6ee..e880aa24b 100644
--- a/src/libserver/css/css_colors_list.hxx
+++ b/src/libserver/css/css_colors_list.hxx
@@ -20,7 +20,7 @@
 #pragma once
 
 #include <string_view>
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "css_value.hxx"
 
 namespace rspamd::css {
@@ -30,7 +30,7 @@ namespace rspamd::css {
  * TODO: think about frozen structs when we can deal with 700 values without
  * compiler limits...
  */
-static const robin_hood::unordered_flat_map<std::string_view, css_color> css_colors_map{
+static const ankerl::unordered_dense::map<std::string_view, css_color> css_colors_map{
 		{"aliceblue",            {240, 248, 255}},
 		{"antiquewhite",         {250, 235, 215}},
 		{"antiquewhite1",        {255, 239, 219}},
diff --git a/src/libserver/css/css_rule.hxx b/src/libserver/css/css_rule.hxx
index acf44ba86..c942b8795 100644
--- a/src/libserver/css/css_rule.hxx
+++ b/src/libserver/css/css_rule.hxx
@@ -21,7 +21,7 @@
 #include "css_value.hxx"
 #include "css_property.hxx"
 #include "css_parser.hxx"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "libutil/cxx/util.hxx"
 #include "libutil/cxx/hash_util.hxx"
 #include <vector>
@@ -121,7 +121,7 @@ public:
 	auto compile_to_block(rspamd_mempool_t *pool) const -> rspamd::html::html_block *;
 
 private:
-	robin_hood::unordered_flat_set<rule_shared_ptr, rule_shared_hash, rule_shared_eq> rules;
+	ankerl::unordered_dense::set<rule_shared_ptr, rule_shared_hash, rule_shared_eq> rules;
 };
 
 using css_declarations_block_ptr = std::shared_ptr<css_declarations_block>;
diff --git a/src/libserver/css/css_value.cxx b/src/libserver/css/css_value.cxx
index 6982647f4..7a451e1e5 100644
--- a/src/libserver/css/css_value.cxx
+++ b/src/libserver/css/css_value.cxx
@@ -19,7 +19,7 @@
 #include "frozen/unordered_map.h"
 #include "frozen/string.h"
 #include "libutil/util.h"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "fmt/core.h"
 
 #define DOCTEST_CONFIG_IMPLEMENTATION_IN_DLL
diff --git a/src/libserver/html/html_entities.cxx b/src/libserver/html/html_entities.cxx
index 8a3ff61da..f1bc91963 100644
--- a/src/libserver/html/html_entities.cxx
+++ b/src/libserver/html/html_entities.cxx
@@ -20,7 +20,7 @@
 #include <string>
 #include <utility>
 #include <vector>
-#include <contrib/robin-hood/robin_hood.h>
+#include "contrib/ankerl/unordered_dense.h"
 #include <unicode/utf8.h>
 #include <unicode/uchar.h>
 #include "libutil/cxx/util.hxx"
@@ -2168,9 +2168,9 @@ static const html_entity_def html_entities_array[] = {
 };
 
 class html_entities_storage {
-	robin_hood::unordered_flat_map<std::string_view, html_entity_def> entity_by_name;
-	robin_hood::unordered_flat_map<std::string_view, html_entity_def> entity_by_name_heur;
-	robin_hood::unordered_flat_map<unsigned, html_entity_def> entity_by_id;
+	ankerl::unordered_dense::map<std::string_view, html_entity_def> entity_by_name;
+	ankerl::unordered_dense::map<std::string_view, html_entity_def> entity_by_name_heur;
+	ankerl::unordered_dense::map<unsigned, html_entity_def> entity_by_id;
 public:
 	html_entities_storage() {
 		auto nelts = G_N_ELEMENTS(html_entities_array);
diff --git a/src/libserver/html/html_tag_defs.hxx b/src/libserver/html/html_tag_defs.hxx
index 812ec2021..e166e0b7c 100644
--- a/src/libserver/html/html_tag_defs.hxx
+++ b/src/libserver/html/html_tag_defs.hxx
@@ -21,7 +21,7 @@
 #include "libutil/cxx/util.hxx"
 
 #include <string>
-#include <contrib/robin-hood/robin_hood.h>
+#include "contrib/ankerl/unordered_dense.h"
 
 namespace rspamd::html {
 
@@ -139,8 +139,8 @@ static const auto html_tag_defs_array = rspamd::array_of(
 );
 
 class html_tags_storage {
-	robin_hood::unordered_flat_map<std::string_view, html_tag_def> tag_by_name;
-	robin_hood::unordered_flat_map<tag_id_t, html_tag_def> tag_by_id;
+	ankerl::unordered_dense::map<std::string_view, html_tag_def> tag_by_name;
+	ankerl::unordered_dense::map<tag_id_t, html_tag_def> tag_by_id;
 public:
 	html_tags_storage() {
 		tag_by_name.reserve(html_tag_defs_array.size());
diff --git a/src/libserver/redis_pool.cxx b/src/libserver/redis_pool.cxx
index 548551ab9..2ea8b727c 100644
--- a/src/libserver/redis_pool.cxx
+++ b/src/libserver/redis_pool.cxx
@@ -23,9 +23,8 @@
 #include "contrib/hiredis/adapters/libev.h"
 #include "cryptobox.h"
 #include "logger.h"
-
 #include <list>
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 
 namespace rspamd {
 class redis_pool_elt;
@@ -91,6 +90,12 @@ class redis_pool_elt {
 	redis_pool_key_t key;
 	bool is_unix;
 public:
+	/* Disable copy */
+	redis_pool_elt() = delete;
+	redis_pool_elt(const redis_pool_elt &) = delete;
+	/* Enable move */
+	redis_pool_elt(redis_pool_elt &&other) = default;
+
 	explicit redis_pool_elt(redis_pool *_pool,
 							const gchar *_db, const gchar *_password,
 							const char *_ip, int _port)
@@ -194,9 +199,9 @@ class redis_pool final {
 	static constexpr const unsigned default_max_conns = 100;
 
 	/* We want to have references integrity */
-	robin_hood::unordered_flat_map<redisAsyncContext *,
+	ankerl::unordered_dense::map<redisAsyncContext *,
 			redis_pool_connection *> conns_by_ctx;
-	robin_hood::unordered_node_map<redis_pool_key_t, redis_pool_elt> elts_by_key;
+	ankerl::unordered_dense::map<redis_pool_key_t, redis_pool_elt> elts_by_key;
 	bool wanna_die = false; /* Hiredis is 'clever' so we can call ourselves from destructor */
 public:
 	double timeout = default_timeout;
@@ -490,9 +495,9 @@ redis_pool::new_connection(const gchar *db, const gchar *password,
 		}
 		else {
 			/* Need to create a pool */
-			auto nelt = elts_by_key.emplace(std::piecewise_construct,
-					std::forward_as_tuple(key),
-					std::forward_as_tuple(this, db, password, ip, port));
+			auto nconn = redis_pool_elt{this, db, password, ip, port};
+			auto nelt = elts_by_key.try_emplace(key,
+					std::move(nconn));
 
 			return nelt.first->second.new_connection();
 		}
diff --git a/src/libserver/symcache/symcache_internal.hxx b/src/libserver/symcache/symcache_internal.hxx
index 9bce37532..063777a71 100644
--- a/src/libserver/symcache/symcache_internal.hxx
+++ b/src/libserver/symcache/symcache_internal.hxx
@@ -34,7 +34,7 @@
 
 #include "rspamd_symcache.h"
 #include "contrib/libev/ev.h"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "contrib/expected/expected.hpp"
 #include "cfg_file.h"
 
@@ -109,9 +109,9 @@ struct order_generation {
 	/* All items ordered */
 	std::vector<cache_item_ptr> d;
 	/* Mapping from symbol name to the position in the order array */
-	robin_hood::unordered_flat_map<std::string_view, unsigned int> by_symbol;
+	ankerl::unordered_dense::map<std::string_view, unsigned int> by_symbol;
 	/* Mapping from symbol id to the position in the order array */
-	robin_hood::unordered_flat_map<unsigned int, unsigned int> by_cache_id;
+	ankerl::unordered_dense::map<unsigned int, unsigned int> by_cache_id;
 	/* It matches cache->generation_id; if not, a fresh ordering is required */
 	unsigned int generation_id;
 
@@ -147,7 +147,7 @@ class symcache {
 private:
 	using items_ptr_vec = std::vector<cache_item_ptr>;
 	/* Map indexed by symbol name: all symbols must have unique names, so this map holds ownership */
-	robin_hood::unordered_flat_map<std::string_view, cache_item_ptr> items_by_symbol;
+	ankerl::unordered_dense::map<std::string_view, cache_item_ptr> items_by_symbol;
 	items_ptr_vec items_by_id;
 
 	/* Items sorted into some order */
diff --git a/src/libserver/symcache/symcache_item.cxx b/src/libserver/symcache/symcache_item.cxx
index bdc378f32..588d2e93f 100644
--- a/src/libserver/symcache/symcache_item.cxx
+++ b/src/libserver/symcache/symcache_item.cxx
@@ -32,7 +32,7 @@ struct augmentation_info {
 
 /* A list of internal augmentations that are known to Rspamd with their weight */
 static const auto known_augmentations =
-		robin_hood::unordered_flat_map<std::string, augmentation_info, rspamd::smart_str_hash, rspamd::smart_str_equal>{
+		ankerl::unordered_dense::map<std::string, augmentation_info, rspamd::smart_str_hash, rspamd::smart_str_equal>{
 				{"passthrough", {
 										.weight = 10,
 										.implied_flags = SYMBOL_TYPE_IGNORE_PASSTHROUGH
diff --git a/src/libserver/symcache/symcache_item.hxx b/src/libserver/symcache/symcache_item.hxx
index 2c2072fd3..50e321265 100644
--- a/src/libserver/symcache/symcache_item.hxx
+++ b/src/libserver/symcache/symcache_item.hxx
@@ -200,7 +200,7 @@ struct cache_item : std::enable_shared_from_this<cache_item> {
 	id_list forbidden_ids{};
 
 	/* Set of augmentations */
-	robin_hood::unordered_flat_set<std::string, rspamd::smart_str_hash, rspamd::smart_str_equal> augmentations;
+	ankerl::unordered_dense::set<std::string, rspamd::smart_str_hash, rspamd::smart_str_equal> augmentations;
 
 	/* Dependencies */
 	std::vector<cache_dependency> deps;
diff --git a/src/libstat/backends/cdb_backend.cxx b/src/libstat/backends/cdb_backend.cxx
index d0915d2d7..5e188b978 100644
--- a/src/libstat/backends/cdb_backend.cxx
+++ b/src/libstat/backends/cdb_backend.cxx
@@ -27,7 +27,7 @@
 #include <string>
 #include <optional>
 #include "contrib/expected/expected.hpp"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include "fmt/core.h"
 
 namespace rspamd::stat::cdb {
@@ -87,7 +87,7 @@ private:
 	 * We store weak pointers here to allow owning cdb statfiles to free
 	 * expensive cdb before this cache is terminated (e.g. on dynamic cdb reload)
 	 */
-	robin_hood::unordered_flat_map<std::string, std::weak_ptr<struct cdb>> elts;
+	ankerl::unordered_dense::map<std::string, std::weak_ptr<struct cdb>> elts;
 
 	struct cdb_deleter {
 		void operator()(struct cdb *c) const {
diff --git a/src/libstat/backends/http_backend.cxx b/src/libstat/backends/http_backend.cxx
index 3f4f1abd0..69c735a09 100644
--- a/src/libstat/backends/http_backend.cxx
+++ b/src/libstat/backends/http_backend.cxx
@@ -19,7 +19,7 @@
 #include "libserver/http/http_connection.h"
 #include "libserver/mempool_vars_internal.h"
 #include "upstream.h"
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 #include <vector>
 
 namespace rspamd::stat::http {
@@ -91,7 +91,7 @@ public:
 						bool learn) -> bool;
 private:
 	http_backends_collection *all_backends;
-	robin_hood::unordered_flat_map<int, const struct rspamd_statfile_config *> seen_statfiles;
+	ankerl::unordered_dense::map<int, const struct rspamd_statfile_config *> seen_statfiles;
 	struct upstream *selected;
 private:
 	http_backend_runtime(struct rspamd_task *task, bool is_learn) :
diff --git a/src/libutil/cxx/hash_util.hxx b/src/libutil/cxx/hash_util.hxx
index d8529774e..afad29fa5 100644
--- a/src/libutil/cxx/hash_util.hxx
+++ b/src/libutil/cxx/hash_util.hxx
@@ -20,7 +20,7 @@
 
 #include <string_view>
 #include <string>
-#include "contrib/robin-hood/robin_hood.h"
+#include "contrib/ankerl/unordered_dense.h"
 
 
 namespace rspamd {
@@ -81,10 +81,10 @@ struct smart_str_equal {
 struct smart_str_hash {
 	using is_transparent = void;
 	auto operator()(const std::string &a) const {
-		return robin_hood::hash<std::string>()(a);
+		return ankerl::unordered_dense::hash<std::string>()(a);
 	}
 	auto operator()(const std::string_view &a) const {
-		return robin_hood::hash<std::string_view>()(a);
+		return ankerl::unordered_dense::hash<std::string_view>()(a);
 	}
 };
 
diff --git a/src/lua/lua_html.cxx b/src/lua/lua_html.cxx
index 666b08a60..cecf4bb5c 100644
--- a/src/lua/lua_html.cxx
+++ b/src/lua/lua_html.cxx
@@ -21,7 +21,7 @@
 #include "libserver/html/html_block.hxx"
 #include "images.h"
 
-#include <contrib/robin-hood/robin_hood.h>
+#include "contrib/ankerl/unordered_dense.h"
 #include <frozen/string.h>
 #include <frozen/unordered_map.h>
 
@@ -406,7 +406,7 @@ lua_html_foreach_tag (lua_State *L)
 	const gchar *tagname;
 	gint id;
 	auto any = false;
-	robin_hood::unordered_flat_set<int> tags;
+	ankerl::unordered_dense::set<int> tags;
 
 
 	if (lua_type (L, 2) == LUA_TSTRING) {