The std::is_nothrow_move_assignable template of C++ STL is present in the <type_traits> header file. The std::is_nothrow_move_assignable template of C++ STL is used to check whether the T is a move assignable type or not and this is known for not to throw any exception. It return the boolean value true if T is move assignable type, otherwise return false.
Header File:
#include<type_traits>
Template Class:
template< class T > struct is_move_assignable;
Syntax:
std::is_move_assignable<T>::value
Parameter: The template std::is_nothrow_move_assignable accepts a single parameter T(Trait class) to check whether T is move assignable with no throw exception or not.
Return Value: The template std::is_nothrow_move_assignable returns a boolean variable as shown below:
- True: If the type T is move assignable type.
- False: If the type T is not a move assignable type.
Below is the program to demonstrate std::is_nothrow_move_assignable:
Program:
// C++ program to illustrate // std::is_nothrow_move_assignable #include <bits/stdc++.h> #include <type_traits> using namespace std;
// Declare structures struct A {
}; struct B {
B& operator=(B&) = delete ;
}; struct Ex1 {
Ex1() {}
Ex1(Ex1&&)
{
cout << "Throwing move constructor!" ;
}
Ex1( const Ex1&)
{
cout << "Throwing copy constructor!" ;
}
}; struct Ex2 {
Ex2() {}
Ex2(Ex2&&) noexcept
{
cout << "Non-throwing move constructor!" ;
}
Ex2( const Ex2&) noexcept
{
cout << "Non-throwing copy constructor!" ;
}
}; // Driver Code int main()
{ cout << boolalpha;
// Check if int is a move
// assignable or not
cout << "int: "
<< is_nothrow_move_assignable< int >::value
<< endl;
// Check if struct A is a move
// assignable or not
cout << "struct A: "
<< is_nothrow_move_assignable<A>::value
<< endl;
// Check if struct B is a move
// assignable or not
cout << "struct B: "
<< is_nothrow_move_assignable<B>::value
<< endl;
// Check if struct Ex1 is a move
// assignable or not
cout << "struct Ex1: "
<< is_nothrow_move_assignable<Ex1>::value
<< endl;
// Check if struct Ex2 is a move
// assignable or not
cout << "struct Ex2: "
<< is_nothrow_move_assignable<Ex2>::value
<< endl;
return 0;
} |
int: true struct A: true struct B: false struct Ex1: false struct Ex2: false
Reference: http://www.cplusplus.com/reference/type_traits/is_nothrow_move_assignable/