On Mon, Oct 4, 2010 at 12:41 PM, Hans Wennborg <[email protected]> wrote: > On Mon, Oct 4, 2010 at 12:23 PM, Leandro Graciá Gil > <[email protected]> wrote: >>> In summary, looking at code like this >>> >>> B& b = c->foo(); >>> ... >>> b.m(); >>> >>> If c->foo() returns a temporary ("return B();"), then it is safe. >> >> Maybe I'm wrong, but are you completely sure about this one? I would say >> that the temporary object created in return B() will cease to exist as soon >> as it returns (just after the constructor finishes). > > Actually, the temporary object ceases to exist as soon as *the > expression containing the call completes*, as Peter Kasting pointed > out. So this should be ok: > > B b = c->foo(); // foo() returns a reference to a temporary, and the > temporary is then copied to b, then destroyed > > And this too: > > c->foo().m(); > > But not this: > > B& b = c->foo(); > // the temporary is gone now > b.m(); // trouble > > > Hans >
I take it all back! I read that standards quote a bit too fast :) "A temporary bound to the returned value in a function return statement persists until the function exists". I suppose that says it all. Leandro is right, I think. _______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
