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Defined in header <concepts> | ||
template<class T,class U> concept same_as=/* see below */; | (since C++20) | |
The conceptsame_as<T, U> is satisfied if and only ifT andU denote the same type.
std::same_as<T, U>subsumesstd::same_as<U, T> and vice versa.
Contents |
namespace detail{template<class T,class U> concept SameHelper=std::is_same_v<T, U>;} template<class T,class U>concept same_as= detail::SameHelper<T, U>&& detail::SameHelper<U, T>; |
#include <concepts>#include <iostream> template<typename T,typename ...U>concept either=(std::same_as<T, U>|| ...); template<typename T>concept is_printable=std::integral<T>||std::floating_point<T>|| either<std::remove_cvref_t<std::remove_pointer_t<std::decay_t<T>>>,char,wchar_t>; void println(is_printableautoconst ...arguments){(std::wcout<< ...<< arguments)<<'\n';} int main(){ println("Example: ",3.14," : ",42," : [",'a', L'-', L"Z]");}
Output:
Example: 3.14 : 42 : [a-Z]
same_as [concept.same] same_as [concept.same] (C++11) | checks if two types are the same (class template)[edit] |
