Why copy constructor is called?

Asked Nov 13 '16 at 17:36

Active Nov 13 '16 at 18:02

Viewed 62 times

I have the test code:

struct A
{    
    A (){}

    A (const A & a)
    {
        std::cout<<"copy A";
    }
};

int main()
{
    A a;
    const A& a1 = static_cast<A>(a);

    return 0;
}

My question is why copy constructor is called? UPD: added the description of class A. Program output is: "copy A"

edited Nov 13 '16 at 18:02

asked Nov 13 '16 at 17:36

M90

Because the `static_cast` creates a temporary object. – Sam Varshavchik Nov 13 '16 at 17:37
@SamVarshavchik, Provide link, please – M90 Nov 13 '16 at 17:40
1

http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list – Sam Varshavchik Nov 13 '16 at 17:40
1

The most important question is: what's `A`? Where is it defined? I can imagine a bunch of cases where copy constructor is not called. – skypjack Nov 13 '16 at 17:52
@M90 - `static_cast(a)` obviously creates a new `B` from `a`. Now guess what `static_cast(a)` does. – Bo Persson Nov 13 '16 at 19:06

Why copy constructor is called?

0 Answers0