<type_traits>

class template
<type_traits>

std::is_copy_constructible

template <class T> struct is_copy_constructible;
Is copy constructible

Trait class that identifies whether T is a copy constructible type.

A copy constructible type is a type that can be constructed from a value or reference of the same type. This includes scalar types and copy constructible classes.

A copy constructible class is a class that has a copy constructor (either its implicit constructor or a custom defined one).

The is_copy_constructible class inherits from integral_constant as being either true_type or false_type, depending on whether T is copy constructible.

Template parameters

T
A complete type, or void (possible cv-qualified), or an array of unknown bound.

Member types

Inherited from integral_constant:
member typedefinition
value_typebool
typeeither true_type or false_type

Member constants

Inherited from integral_constant:
member constantdefinition
valueeither true or false

Member functions

Inherited from integral_constant:

Example

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// is_copy_constructible example #include <iostream> #include <type_traits> struct A { }; struct B { B(B&&){} }; struct C { C(const C&){} }; int main() { std::cout << std::boolalpha; std::cout << "is_copy_constructible:" << std::endl; std::cout << "int: " << std::is_copy_constructible<int>::value << std::endl; std::cout << "A: " << std::is_copy_constructible<A>::value << std::endl; std::cout << "B: " << std::is_copy_constructible<B>::value << std::endl; std::cout << "C: " << std::is_copy_constructible<C>::value << std::endl; return 0; }

Output:
is_copy_constructible: int: true A: true B: false C: true 


See also