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std::copy_constructible(3) C++ Standard Libary std::copy_constructible(3)


std::copy_constructible - std::copy_constructible


Defined in header <concepts>
template< class T >

concept copy_constructible =
std::move_constructible<T> &&
std::constructible_from<T, T&> && std::convertible_to<T&, T> && (since C++20)
std::constructible_from<T, const T&> && std::convertible_to<const
T&, T> &&

std::constructible_from<T, const T> && std::convertible_to<const
T, T>;

The concept copy_constructible is satisfied if T is an lvalue reference type, or if
it is a move_constructible 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).

Semantic requirements

If T is an object type, then copy_constructible<T> is modeled only if given

* v, an 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 and v is not modified;
* T(v) is equal to v and does not modify v.

See also

is_nothrow_copy_constructible checks if a type has a copy constructor
(C++11) (class template)