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std::same_as

Defined in header <concepts> 
template< class T, class U >
concept same_as = /* see below */;
 (since C++20)

The concept same_as<T, U> is satisfied if and only if T and U denote the same type.

std::same_as<T, U> subsumes std::same_as<U, T> and vice versa.

Possible implementation

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>;

Example

#include <concepts>
#include <iostream>
 
template<typename T, typename ... U>
concept IsAnyOf = (std::same_as<T, U> || ...);
 
template<typename T>
concept IsPrintable = std::integral<T> || std::floating_point<T> ||
    IsAnyOf<std::remove_cvref_t<std::remove_pointer_t<std::decay_t<T>>>, char, wchar_t>;
 
void println(IsPrintable auto const ... arguments)
{
    (std::wcout << ... << arguments) << '\n';
}
 
int main()
{
    println("Example: ", 3.14, " : ", 42, " : [", 'a', L'-', L"Z]");
}

Output:

Example: 3.14 : 42 : [a-Z]

See also

(C++11)
checks if two types are the same
(class template)

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https://en.cppreference.com/w/cpp/concepts/same_as