<type_traits>

class template
<type_traits>

std::is_nothrow_copy_assignable

template <class T> struct is_nothrow_copy_assignable;
Is copy assignable throwing no exceptions

Trait class that identifies whether T is a copy assignable type, and such operation is known not to throw any exception.

This class inherits from integral_constant as being either true_type or false_type.

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_nothrow_copy_assignable example
#include <iostream>
#include <type_traits>

struct A { };
struct B { B& operator= (const B&) {return *this;} };
struct C { C& operator= (const C&) noexcept {return *this;} };

int main() {
  std::cout << std::boolalpha;
  std::cout << "is_nothrow_copy_assignable:" << std::endl;
  std::cout << "int: " << std::is_nothrow_copy_assignable<int>::value << std::endl;
  std::cout << "A: " << std::is_nothrow_copy_assignable<A>::value << std::endl;
  std::cout << "B: " << std::is_nothrow_copy_assignable<B>::value << std::endl;
  std::cout << "C: " << std::is_nothrow_copy_assignable<C>::value << std::endl;
  return 0;
}

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


See also