In copy-initialization, is the call to the copy constructor explicit or implicit?

Question

class AAA {
public:
    explicit AAA(const AAA&) {}
    AAA(int) {}
};


int main() {
    AAA a = 1;
    return 0;
}

In the above code, as I unders

Answer 1

Looks like this bug: g++ fails to call explicit constructors in the second step of copy initialization

g++ fails to compile the following code

struct X
{
    X(int) {}
    explicit X(X const &) {}
};

int main()
{
    X x = 1; // error: no matching function for call to 'X::X(X)'
}

The second step of a copy initialization (see 8.5/16/6/2) is a direct-initialization where explicit constructors shall be considered as candidate functions.

Answer 2

Looks like copy constructor is never called . Only constructor is called . The following code may call copy constructor

AAA a = 1;
AAA ab = a;

Not sure why G++ is compiling it .