Does C++ optimise construction-and-copy into a copy constructor?

Question

Does a C++ compiler automatically convert:

MyObject object2 = object1;

into

MyObject object2( object1 );

?

Or does it treat it like:

MyObject object2;
object2 = object1;

?

Answer 1

Yes, it's the first one. It's not an "optimisation"; they are two different syntaxes for invoking the copy constructor.

If you want to prove it, try defining a private assignment operator for MyObject. The code should still compile, which proves it can't be equivalent to the second mechanism.