Something

njl36a-7001:/home/yzaytsev/src $ cat ./copy.cpp
#include <iostream>
class X { public:X(){} X (const X&) { std::cout << "X\n"; } X& operator=(const X&) {std::cout << "X\n"; } };
class C {public: int i; X x; };
int main()
{
C a, b;
a.i =10;
b = a;
std::cout << "b.i: "<< b.i << '\n';
}
njl36a-7001:/home/yzaytsev/src $ CC=g++ CXX=g++ make copy
make: `copy' is up to date.
njl36a-7001:/home/yzaytsev/src $ ./copy
X
b.i: 10
njl36a-7001:/home/yzaytsev/src $