[Project] Add fu2 library to better functions abstractions

CMakeLists.txt

@@ -119,6 +119,7 @@ INCLUDE_DIRECTORIES("${CMAKE_SOURCE_DIR}/"
 		"${CMAKE_SOURCE_DIR}/contrib/frozen/include"
 		"${CMAKE_SOURCE_DIR}/contrib/fmt/include"
 		"${CMAKE_SOURCE_DIR}/contrib/doctest"
+		"${CMAKE_BINARY_DIR}/contrib/fu2/include"
 		"${CMAKE_BINARY_DIR}/src" #Stored in the binary dir
 		"${CMAKE_BINARY_DIR}/src/libcryptobox")
 

contrib/DEPENDENCY_INFO.md

@@ -33,3 +33,4 @@
 | frozen        | 1.0.1   | Apache 2            | NO      |                    |
 | fmt           | 7.1.3   | MIT                 | NO      |                    |
 | doctest       | 2.4.5   | MIT                 | NO      |                    |
+| function2     | 4.1.0   | Boost               | NO      |                    |

contrib/fu2/LICENSE.txt

@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+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, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.