C++ named requirements: CopyConstructible

Specifies that an instance of the type can be copy-constructed from an lvalue expression.

Requirements

The type T satisfies CopyConstructible if.

• The type T satisfies MoveConstructible, and

Given.

• v, an lvalue expression of type T or const T or an rvalue expression of type const T
• u, an arbitrary identifier

The following expressions must be valid and have their specified effects:

Expression	Post-conditions
T u = v;	The value of u is equivalent to the value of v. The value of v is unchanged.
T(v)	The value of T(v) is equivalent to the value of v. The value of v is unchanged.

The expression v.~T() also must be valid, and, for lvalue v, the expression &v must have the type T* or const T* and must evaluate to the address of v.

(until C++11)

Notes

Until C++11, classes that overloaded operator& were not CopyConstructible and thus were not usable in the standard library containers. This is a design decision in C++98 (instead of a defect, see LWG issue 390).

Since C++11, the standard library uses std::addressof whenever the address of an object is needed.

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)
copy_constructible (C++20)	specifies that an object of a type can be copy constructed and move constructed (concept)