C++ copy-construct construct-and-assign question

Question

Here is an extract from item 56 of the book \"C++ Gotchas\":

It\'s not uncommon to see a simple initialization of a Y object written any of three

Answer 1

The compiler is permitted to optimize cases b and c to be the same as a. Further, copy construction and assignment operator calls can be wholly eliminated by the compiler anyway, so whatever you see isn't necessarily the same with different compilers or even compiler settings.