std::is_copy_constructible in C++ with Examples

The std::is_copy_constructible template of C++ STL is present in the <type_traits> header file. The std::is_copy_constructible template of C++ STL is used to check whether the T is copy constructible or not. 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_copy_constructible;

Syntax:

std::is_copy_constructible <int> ::value
std::is_copy_constructible>class T> ::value

Parameters: This template accepts a single parameter T(Trait class) to check if T is copy constructible or not.

Return Value: This template returns a boolean variable as shown below:

• True: If the type T is copy constructible.
• False: If the type T is not a copy constructible./li>

Below programs illustrates the std::is_copy_constructiblev template in C/C++:

Program:

// C++ program to illustrate
// std::is_copy_constructible example
#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

// Declare structures
struct B {
};
struct A {
    A& operator=(A&) = delete;
};

// Driver Code
int main()
{
    cout << boolalpha;

    // Check that if char is copy
    // constructible or not
    cout << "char: "
         << is_copy_constructible<char>::value
         << endl;

    // Check that if int is copy
    // constructible or not
    cout << "int: "
         << is_copy_constructible<int>::value
         << endl;

    // Check that if int[2] is copy
    // constructible or not
    cout << "int[2]: "
         << is_copy_constructible<int[2]>::value
         << endl;

    // Check that if struct A is copy
    // constructible or not
    cout << "struct A: "
         << is_copy_constructible<A>::value
         << endl;

    // Check that if struct B is copy
    // constructible or not
    cout << "struct B: "
         << is_copy_constructible<B>::value
         << endl;

    return 0;
}

Output:

char: true
int: true
int[2]: false
struct A: true
struct B: true

Reference: http://www.cplusplus.com/reference/type_traits/is_copy_constructible/