#include <type_traits>

template <class T>
struct is_copy_assignable;

std::is_copy_assignable >class T> ::value

// C++ program to illustrate
// std::is_copy_assignable example
#include <bits/stdc++.h>
#include <type_traits>
  
using namespace std;
  
// Declare structures
struct A {
};
  
struct B {
    B& operator=(const B&) = delete;
};
  
struct C {
    C(C&&) {}
};
  
// Driver Code
int main()
{
  
    cout << boolalpha;
  
    // Check if char is_copy_assignable?
    cout << "char: "
         << is_copy_assignable<char>::value
         << endl;
  
    // Check if struct A is_copy_assignable?
    cout << "struct A: "
         << is_copy_assignable<A>::value
         << endl;
  
    // Check if struct B is_copy_assignable?
    cout << "struct B: "
         << is_copy_assignable<B>::value
         << endl;
  
    // Check if struct C is_copy_assignable?
    cout << "struct C: "
         << is_copy_assignable<C>::value
         << endl;
  
    // Check if int[2] is_copy_assignable?
    cout << "int[2]: "
         << is_copy_assignable<int[2]>::value
         << endl;
  
    return 0;
}

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