<type_traits>

class template
<type_traits>

std::is_trivially_assignable

template <class T, class U> struct is_trivially_assignable;
Is trivially assignable

Trait class that identifies whether U is a type trivially assignable to T.

This class inherits from integral_constant as being either true_type or false_type, depending on whether T support being assigned U trivially.

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_trivially_assignable example
#include <iostream>
#include <type_traits>

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

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

Output:
is_trivially_assignable:
int=short: true
A=A: true
A=B: false
B=A: true
C=A: false


See also