The std::is_nothrow_copy_constructible template of C++ STL is present in the <type_traits> header file. The std::is_nothrow_copy_constructible template of C++ STL is used to check whether T is copy constructible type or not and this is known for not to throw any exception. It return the boolean value true if T is copy constructible type, otherwise return false.
Header File:
#include<type_traits>
Template Class:
template <class T> struct is_nothrow_copy_constructible
Syntax:
is_nothrow_copy_constructible<T>::value
Parameter: The template std::is_nothrow_copy_constructible accepts a single parameter T(Trait class) to check whether T is copy constructible type or not.
Return Value: The template std::is_nothrow_copy_constructible returns a boolean variable as shown below:
- True: If type T is a copy constructible type.
- False: If type T is not a copy constructible type.
Below is the program to demonstrate std::is_nothrow_copy_constructible in C++:
Program 1:
// C++ program to illustrate // std::is_nothrow_copy_constructible #include <bits/stdc++.h> #include <type_traits> using namespace std;
// Define Classes class X {
}; class Y {
Y( const Y&) {}
}; // Driver Code int main()
{ cout << boolalpha;
// Check if int is no throw copy
// constructible
cout << "int: "
<< is_nothrow_copy_constructible< int >::value
<< endl;
// Check if class X is no throw copy
// constructible
cout << "class X: "
<< is_nothrow_copy_constructible<X>::value
<< endl;
// Check if class Y is no throw copy
// constructible
cout << "class Y: "
<< is_nothrow_copy_constructible<Y>::value
<< endl;
return 0;
} |
int: true class X: true class Y: false
Program 2:
// C++ program to illustrate // std::is_nothrow_copy_constructible #include <iostream> #include <type_traits> using namespace std;
// Declare structures struct A {
}; struct B {
B( const B&) {}
}; struct C {
C( const C&)
noexcept {}
}; // Driver Code int main()
{ cout << boolalpha;
cout << "is_nothrow_copy_constructible:"
<< endl;
cout << "int is_nothrow_copy_constructible? "
<< is_nothrow_copy_constructible< int >::value
<< endl;
cout << "A is_nothrow_copy_constructible? "
<< is_nothrow_copy_constructible<A>::value
<< endl;
cout << "B is_nothrow_copy_constructible? "
<< is_nothrow_copy_constructible<B>::value
<< endl;
cout << "C is_nothrow_copy_constructible? "
<< is_nothrow_copy_constructible<C>::value
<< endl;
return 0;
} |
is_nothrow_copy_constructible: int is_nothrow_copy_constructible? true A is_nothrow_copy_constructible? true B is_nothrow_copy_constructible? false C is_nothrow_copy_constructible? true
Reference: http://www.cplusplus.com/reference/type_traits/is_nothrow_copy_constructible/