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
