Question

I’ve often seen that people create objects in C++ using

Thing myThing("asdf");

Instead of this:

Thing myThing = Thing("asdf");

This seems to work (using gcc), at least as long as there are no templates involved. My question now, is the first line correct and if so should I use it?

Answer 1

Both lines are in fact correct but do subtly different things.

The first line creates a new object on the stack by calling a constructor of the format Thing(const char*).

The second one is a bit more complex. It essentially does the following

1. Create an object of type Thing using the constructor Thing(const char*)
2. Create an object of type Thing using the constructor Thing(const Thing&)
3. Call ~Thing() on the object created in step #1