[cmake-developers] C++11 and target_compiler_feature proposal

[Brad King]

On 10/22/2013 11:31 AM, Stephen Kelly wrote:
> Further-on, you responded:
> 
>> Why do you need to check features of a compiler not currently enabled?

That was talking about the platform file tables, not the header.

> I thought the VERSION would be optional and would default to 
> CMAKE_MINIMUM_REQUIRED_VERSION:
> 
>  http://thread.gmane.org/gmane.comp.programming.tools.cmake.devel/6726/focus=7812

Yes, okay.

>> Actually it appears this header will duplicate most of the compiler
>> feature
>> knowledge encoded in the CMake platform modules we discussed before.  I
>> wonder if we can come up with a representation that can be used to
>> generate both.
> 
> Probably. However, that means that we either shouldn't use the clang 
> __has_feature() test that I implemented, or we'll have to duplicate all of 
> that information anyway.

CMAKE_CXX_COMPILER is always set to the proper full path these days,
even in the IDE generators, so I wonder if we could actually run it
against the header file to detect the features available for the
current compiler instead of hard-coding a table in the platform
information files.  Then the checks would all be done in one place
via the preprocessor and __has_feature if available.

-Brad