下面 C++ 代码的运行结果是（）
#include <iostream>
using std::cout;
using std::endl;
using std::move;
struct Test {
Test() = default;
Test(const Test& that) {
cout << "copy constructor" << endl;
}
Test& operator=(const Test& rhs) {
cout << "copy assignment operator" << endl;
return *this;
}
};
int main() {
Test a, b;
a = b;
Test c = move(b);
return 0;
} 
