Explicit C ++ Constructor and Casting

Question

In the book "Effective C ++", paragraph 27

class Widget {
public:
explicit Widget(int size);
...
};
void doSomeWork(const Widget& w);
doSomeWork(Widget(15)); // create Widget from int
                        // with function-style cast

I'm not sure exactly what happens when doSomeWork is called. I think the w parameter of the doSomeWork function is initialized by another Widget using the copy constructor, but where is the other Widget? Is this a temporary object created by casting as indicated in the comments? Can someone tell me in detail what was caused when the doSomeWork function parameter was initialized?

Answer 1

The wfunction parameter doSomeWorkis the one Widgetyou created as the parameter in the line

doSomeWork(Widget(15));

doSomeWork a Widget, . , , , doSomeWork(const Widget &w) pass .

, , , .