std::CopyConstructible

 

C++

Language

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

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Numerics library

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Regular expressions library (C++11)

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Technical Specifications

 

Concepts library

Core language concepts
Same DerivedFrom ConvertibleTo CommonReference Common	Integral SignedIntegral UnsignedIntegral Assignable SwappableSwappableWith	Destructible Constructible DefaultConstructible MoveConstructible CopyConstructible
Comparison concepts
Boolean	EqualityComparableEqualityComparableWith	StrictTotallyOrderedStrictTotallyOrderedWith
Object concepts
Movable Copyable	Semiregular Regular
Callable concepts
InvocableRegularInvocable	Predicate	Relation StrictWeakOrder

 

Defined in header <concepts>
template <class T> concept CopyConstructible =   std::MoveConstructible<T> &&   std::Constructible<T, T&> && std::ConvertibleTo<T&, T> &&   std::Constructible<T, const T&> && std::ConvertibleTo<const T&, T> &&   std::Constructible<T, const T> && std::ConvertibleTo<const T, T>;		(since C++20)

The concept CopyConstructible is satisfied if T is an lvalue reference type, or if it is a MoveConstructible object type where an object of that type can constructed from a (possibly const) lvalue or const rvalue of that type in both direct- and copy-initialization contexts with the usual semantics (a copy is constructed with the source unchanged).

More precisely, if T is an object type, then CopyConstructible<T> is satisfied only if given

• v, a lvalue of type (possibly const) T or an rvalue of type const T,

the following are true:

• After the definition T u = v;, u is equal to v;
• T(v) is equal to v.

See also

is_copy_constructibleis_trivially_copy_constructibleis_nothrow_copy_constructible (C++11)(C++11)(C++11)

checks if a type has a copy constructor (class template)