Size of empty class in C++

The size of empty class is 1 because The standard does not allow objects (and classes thereof) of size 0, since that would make it possible for two distinct objects to have the same memory address. That’s why even empty classes must have a size of (at least) 1.

#include<iostream>
using namespace std;
class class_1 {
      
};

int main()
{
    cout<<sizeof(class_1);
	getchar();
	return 0;
}