Why doesn't any constructor get called?

Asked Aug 01 '19 at 17:46

Active Aug 01 '19 at 18:02

Viewed 70 times

class X {
public:
    X() {}
    X(const X&) {
        std::cou << "copy constructor";
    }
    X(X&&) {
        std::cout << "move constructor";
    }
};

X func() { return X(); }

int main() {
    X x(func()); // nothing is printed
}

I think that the move constructor must be called, but neither copy constructor nor move constructor gets called. Is this because of copy ellision?

edited Aug 01 '19 at 18:02

asked Aug 01 '19 at 17:46

beginpluses

I _highly_ recommend using more descriptive variable names. – Michael Bianconi Aug 01 '19 at 17:49
Can you put some print statement in constuctors and post a link to the online complied code? – iammilind Aug 01 '19 at 17:54
Added std::cout – beginpluses Aug 01 '19 at 18:03
@beginpluses Put some print in the default constructor. It will be called. There is elision of the move and copy constructors but one of them shall be acceptable. – Vlad from Moscow Aug 01 '19 at 18:07
I'm interested only in copy and move constructors. Default one is called, ofcourse – beginpluses Aug 01 '19 at 18:21
"Why doesn't any constructor get called?" This `X() {}` is a constructor. It gets called. – Eljay Aug 01 '19 at 21:41

Why doesn't any constructor get called?

0 Answers0