Why does this call the default constructor?

Question

struct X
{
    X()    { std::cout << \"X()\\n\";    }
    X(int) { std::cout << \"X(int)\\n\"; }
};

const int answer = 42;

int main()
{
    X(answer);
         


        

Answer 1

The parentheses are optional. What you said is identical to X answer;, and it's a declaration statement.