Note: I'm not taking a position on the language feature, just between your two designs.
-Ekr On Sun, Oct 11, 2015 at 5:34 AM, Eric Rescorla <e...@rtfm.com> wrote: > > On Sun, Oct 11, 2015 at 4:28 AM, Aryeh Gregor <a...@aryeh.name> wrote: > >> On Sun, Oct 11, 2015 at 2:09 PM, Aryeh Gregor <a...@aryeh.name> wrote: >> > A new language feature could be used to solve this: allow conversion >> > operators to behave differently based on how the variable is declared. >> > For instance, it might convert differently if the source or >> > destination is a local variable, global/static variable, member >> > variable, or function parameter. This would allow our problem to be >> > easily solved by defining something in nsCOMPtr like: >> > >> > operator T* [[parameter]]()&&; >> > >> > while leaving the operator deleted for non-parameters. >> >> Actually, you could perhaps do even better than that. Use nsCOMPtr<T> >> for refcounted parameters instead of T*, and then delete the T* >> constructor for [[parameter]] nsCOMPtr<T>, and have the constructor >> and destructor for nsCOMPtr parameters not do addref/release. Then >> you have the effect of bug 1194195 without having to introduce a new >> type. nsCOMPtr(/RefPtr) would be the type to use anywhere you want to >> require a strong reference, and it would magically sort out the >> addrefs/releases for you. (Although I know a lot of people don't like >> such magic either, so this isn't strictly superior. But the option >> would be available.) > > > This seems far superior because it encourages people not to unbox > pointers which seems like a good thing all other things being equal. > (I'd actually go further, and say it's a good thing in general, but not > everyone seems to agree....) > > -Ekr > > > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
