Standard Library Concepts Emulation Library
This header-only library provides type traits similar to things defined in C++20 standard library concepts. This library is intended to use for backport C++20 codes to legacy C++ environment.
C++ compiler that supports at least C++11.
Boost Unit Test Framework (Only tests require this)
Since callable concepts depends on std::invoke that was introduced in C++17, corresponding type traits always return false in C++14 or prior.