Re: Patch ping (Re: [wwwdocs] Add __cpp_* feature macros to C++20 entries + other changes that have those in projects/cxx_status.html)

[Jonathan Wakely <jwakely@redhat.com>]

On 21/01/19 14:40 +0100, Jakub Jelinek wrote:
>Hi!
>
>On Sat, Jan 12, 2019 at 02:08:15PM +0100, Jakub Jelinek wrote:
>> Here is an updated patch, that in addition to that makes 9 URLs as we now
>> have #cxx in gcc-9/changes.html and adds missing P0941R2 entry that clang
>> table has.  For that one I'm not 100% sure what to say, I've copied all the
>> macros from http://wg21.link/p0941r2 into two source files (attached below),
>> one for core language features, another one for library and tested those
>> with -std=c++2a with current trunk.  Compared to what the paper lists, we
>> have __has_cpp_attribute (carries_dependency) 0, __cpp_guaranteed_copy_elision
>> and __cpp_nontype_template_parameter_auto not defined.  Is that what we
>> want?  On the library side, __cpp_lib_any, __cpp_lib_execution,
>> __cpp_lib_hardware_interference_size, __cpp_lib_null_iterators,
>> __cpp_lib_parallel_algorithm, __cpp_lib_raw_memory_algorithms,
>> __cpp_lib_to_chars, __cpp_lib_uncaught_exceptions, __cpp_lib_variant
>> macros aren't defined (at least not in <version>) and
>> __cpp_lib_optional, __cpp_lib_shared_ptr_arrays, __cpp_lib_string_view
>> have smaller values than those in the P0941R2.
>> Is that the desirable state given current C++2A implementation status?
>>
>> Ok for wwwdocs (or do you suggest something different for the P0941R2
>> imlementation status)?
>
>I'd like to ping this patch.

For P0941R2 I think we can just say it's supported. For the library
docs I said we support it since GCC 5.1 because that's when we started
defining feature test macros. The point of the paper is to define
macros for the features that are supported, and we've been doing that
for years. If a macro is missing, it's because we don't support the
feature yet, and that's a correct implementation of the macro!