------- Comment #5 from jwakely dot gcc at gmail dot com 2009-12-11 10:39
-------
(In reply to comment #4)
> > But I'm not convinced that doing this is always a mistake.
>
> Since we don't care about the object, we must care about the constructor side
> effect. I seem to be under the impression that ISO C++ allows the construction
> of temporary objects to be optimized away---even if there are side effects in
> the constructor or destructor! Therefore, it's hard to see a valid use case
> for
> this.
Certain temporaries (such as those created during copying or reference binding)
can be optimised away, I don't think it's true of temporaries created
explicitly like this. e.g. I think this should work:
std::ofstream("lockfile"); // creates ./lockfile if it doesn't exist
(assuming write permission in the directory, and ignoring races and other
reasons it might be a bad idea)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36587
