On 28 January 2013 16:07, Graziano Servizi wrote: > Thanks for your kind and quick answer. > > Indeed now the output from sample_code agrees (except minor changes) with > the one given. > > I had to give, however, the noexcept specifier not only to the "move" > functions, but to the copy constructor and copy assignment operator as well. That should not be necessary, and is wrong because the copy constructor allocates memory and so can throw exceptions. > > Trying the same on my own class was unsuccessful: I have a simple, ordinary, > class, say "class my_class", with several constructors, > the copy and move constructors and the move and copy = operators. > > ALL of them are NOW noexcept specified. > > Nevertheless when I write > > my_class my_object(MY_FUNCTION()); > > where MY_FUNCTION() is a function returning a my_class object, > neither the copy constructor nor the move constructor is called: is this due > to RETURN VALUE OPTIMIZATION? Doesn't MY_FUNCTION() is an rvalue? Yes, this is the return value optimisation. To disable it you can compile with -fno-elide-constructors and you will see every copy/move happen, without them being elided. > Must I "noexcept" EVERY method of my_class? No.
