std::CopyConstructible (3) - Linux Manuals

std::CopyConstructible: std::CopyConstructible


std::CopyConstructible - std::CopyConstructible


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

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