result-of – Make Me Engineer

Difference between std::result_of and decltype

May 21, 2023 by Tarik

result_of was introduced in Boost, and then included in TR1, and finally in C++0x. Therefore result_of has an advantage that is backward-compatible (with a suitable library). decltype is an entirely new thing in C++0x, does not restrict only to return type of a function, and is a language feature. Anyway, on gcc 4.5, result_of is … Read more

Metaprograming: Failure of Function Definition Defines a Separate Function

August 7, 2022 by Tarik

Using Walter Brown’s void_t: template <typename…> using void_t = void; It’s very easy to make such a type trait: template<typename T, typename = void> struct has_to_string : std::false_type { }; template<typename T> struct has_to_string<T, void_t<decltype(std::to_string(std::declval<T>()))> > : std::true_type { };