[libcxx-commits] [PATCH] D77519: Fix __is_pointer builtin type trait to work with Objective-C pointer types.

[Louis Dionne via Phabricator via libcxx-commits]

ldionne added inline comments.


================
Comment at: libcxx/include/type_traits:901
+// In clang 10.0.0 and earlier __is_pointer didn't work with Objective-C types.
+#if __has_keyword(__is_pointer) && _LIBCPP_CLANG_VER > 1000
+
----------------
zoecarver wrote:
> ldionne wrote:
> > zoecarver wrote:
> > > ldionne wrote:
> > > > Doesn't `__has_keyword` return a number that can be compared against? `#if __has_keyword(__is_pointer) > some-number` would be better if feasible, because it would handle Clang, AppleClang and any other potential derivative.
> > > I don't think `__has_keyword` returns a comparable number. Libc++ defines `__has_keyword ` using `__is_identifier` [1] and, it seems like all the feature checking macros from clang (including `__is_identifier`) have bool return types [2]. I can add an AppleClang check too if you want. 
> > > 
> > > [1]:
> > > ```
> > > #define __has_keyword(__x) !(__is_identifier(__x))
> > > ```
> > > 
> > > [2]: https://clang.llvm.org/docs/LanguageExtensions.html#feature-checking-macros
> > Ah, you're right. There's no version of AppleClang to put here right now, so I'd say status quo is OK. I can add one later.
> Want me to add a TODO for you?
Sure! Thanks!


Repository:
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  https://reviews.llvm.org/D77519/new/

https://reviews.llvm.org/D77519