std::same_as

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

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Ranges library (C++20)

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Numerics library

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Filesystem library (C++17)

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Technical Specifications

 

Concepts library

Core language concepts same_as derived_from convertible_to common_reference_with common_with integral signed_integral unsigned_integral floating_point swappableswappable_with destructible constructible_from default_initializable move_constructible copy_constructible assignable_from

Comparison concepts equality_comparableequality_comparable_with totally_orderedtotally_ordered_with Object concepts movable copyable semiregular regular Callable concepts invocableregular_invocable predicate relation equivalence_relation strict_weak_order

 

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>;

See also

is_same (C++11)

checks if two types are the same (class template)