Strange behavior of copy-initialization, doesn't call the copy-constructor!

Question

I was reading the difference between direct-initialization and copy-initialization (§8.5/12):

T x(a);  //direct-initialization
T y = a; //copy-initialization         


        

Answer 1

In any compiler, syntax [and semantic] analysis process are done prior to the code optimization process.

The code must be syntactically valid otherwise it won't even compile. Its only in the later phase (i.e code optimization) that the compiler decides to elide the temporary that it creates.

So you need an accessible copy c-tor.