<type_traits>

class template
<type_traits>

std::is_nothrow_assignable

template <class T, class U> struct is_nothrow_assignable;
Is assignable throwing no exceptions

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

Template parameters

T, U
Complete types, 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_assignable example
#include <iostream>
#include <type_traits>

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

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

Output:
is_nothrow_assignable:
A=A: true
B=A: true
B=B: false


See also