How does this code work?

Question

Why there is no output?
#include <iostream>
using namespace std;
class A {
public:
A() {
cout << "Class A!";
}
A(int a = 0) {
cout << "A";
}
};

int main()
{
A a();
}

https://code.sololearn.com/ctnrvYPt2n6D/#cpp

Answer 1

I think A a() does not even call the constructor at all and should've failed the compilation step. So a() in this case is removed from the final executable.