CallableTraits 
CallableTraits is a C++11/C++14/C++17 header-only library for the inspection, synthesis, and decomposition of callable types. Whether it's calling conventions, const volatile &&, or container-like manipulation of parameter lists, CallableTraits provides all the tools you need to rid your codebase of function type specializations. While not for everyone, CallableTraits offers a comprehensive, fine-grained assortment of metafunctions and type traits that can rip apart C++'s most obscure types, and put them back together again with ease. CallableTraits fills the gaps where existing library solutions fall short, aiming to be the "complete type manipulation facility for function types" mentioned in the last section of the C++17 proposal p0172. CallableTraits currently supports GCC 4.8 and later, Clang 3.5 and later, AppleClang from XCode 6.3 and later, and MSVC 19. More notes on compatibility here.
Documentation
- Documentation is a work in progress - see the Issues section for information about what's lacking.
Disclaimer - CallableTraits is currently version 0.3, and is not yet ready for production use. Undiscovered bugs may exist. Documentation is incomplete and may not accurately reflect the state of the code in all places. "Breaking changes" will be made before the 1.0 version is released. Development will take place on the Develop branch, and non-documentation commits merged to the Master branch will be accompanied by a version increment.