Re: [boost] clang type traits

Subject: Re: [boost] clang type traits
From: Daniel James (dnljms_at_[hidden])
Date: 2011-06-13 15:47:36

On 13 June 2011 20:33, Doug Gregor <doug.gregor_at_[hidden]> wrote:
> On Sun, Jun 12, 2011 at 4:27 AM, Daniel James <dnljms_at_[hidden]> wrote:
>> On 10 June 2011 18:13, Doug Gregor <doug.gregor_at_[hidden]> wrote:
>>>
>>> For Clang feature tests, please use __has_feature (or the newer
>>> __has_extension) rather than peeking at Clang version numbers.
>>> __has_feature/__has_extension are language-dialect aware and represent
>>> what the compiler actually supports, while Clang version numbers can
>>> vary widely from one vendor to another (e.g., Apple's version numbers
>>> for its Clang-based compilers are distinct from the LLVM project's
>>> version numbers for Clang).
>>
>> Can we distinguish between Apple's versions and LLVM's versions?
>
> __APPLE_CC__ will say whether we're running on Darwin, but otherwise, no.

That will a problem for working around bugs.

Anyway, I think this means the type traits change is incorrect. Since
this is for a version of clang that won't be released for some time,
it's probably best to revert it in the release branch.