There's precedent for this sort of thing in C++, the move semantics are added on...

eliasmacpherson on Nov 5, 2013 | parent | context | favorite | on: Bjarne Stroustrup Discusses C++

There's precedent for this sort of thing in C++, the move semantics are added on top of this: https://en.wikipedia.org/wiki/Return_value_optimization If you are depending on code in the constructor of an object, this optimisation can catch you out.