[cfe-dev] New C++0x feature support in Clang

[Larry Evans]

On 02/04/11 13:38, Douglas Gregor wrote:
> 
> On Feb 4, 2011, at 11:33 AM, Larry Evans wrote:
> 
>> On 01/26/11 15:45, Douglas Gregor wrote:
>>> Clang has recently gotten much-improved support for the upcoming
>>> C++0x standard. In particular, top-of-tree Clang now supports a
>>> number of C++0x features:
>>>
>>> - Rvalue references (including rvalue references for *this)
>>> - Variadic templates
>>> - Inline namespaces
>>> - Late-specified return types
>>> - Decltype
>>>
>>> You can turn on C++0x support with the -std=gnu++0x (or, if you want
>>> to be more pedantic, -std=c++0x).
>>>
>>> Give it a spin, write some tests, try it out with libc++, and tell us
>>> how it went! And if you get the itch to hack on Clang, there are a
>>> ton of other little C++0x features that you could implement.
>>>
>>> Cheers,
>>> Doug
>>
>> How do I get the attached to compile without the
>> following error about no std::move?
>>
>> /home/evansl/download/llvm/svn/build/Debug+Asserts/bin/clang++ -c
>> -std=c++0x -U__GXX_EXPERIMENTAL_CXX0X__ -c -std=c++0x move.cpp
>> move.cpp:6:16: error: no member named 'move' in namespace 'std'
>>    int j=std::move(i);
>>          ~~~~~^
> 
> I suggest following the preprocessor logic to see what std::move isn't
> getting defined. That -U__GXX_EXPERIMENTAL_CXX0X__ looks really, really
> suspicious, though.

The -U is there because, without it, the errors begin with:

/home/evansl/download/llvm/svn/build/Debug+Asserts/bin/clang++ -c
-std=c++0x -c -std=c++0x move.cpp
In file included from move.cpp:1:
In file included from /usr/include/c++/4.4/memory:48:
In file included from /usr/include/c++/4.4/bits/stl_algobase.h:66:
In file included from /usr/include/c++/4.4/bits/stl_pair.h:60:
In file included from /usr/include/c++/4.4/bits/move.h:38:
In file included from /usr/include/c++/4.4/type_traits:50:
/usr/include/c++/4.4/tr1_impl/type_traits:233:29: error: type qualifier
is not allowed on this function
    struct is_function<_Res(_ArgTypes...) const>

I did read your earlier post with the remark:

  We *should* have enough C++0x support to handle GCC 4.3 and 4.4's
  headers. >= 4.5 headers will still cause problems due to their use of
  generalized initializer lists.

My default g++ is:

  /home/evansl/prog_dev $ g++ -v
  Using built-in specs.
  Target: x86_64-linux-gnu
  Configured with: ../src/configure -v --with-pkgversion='Ubuntu
    4.4.3-4ubuntu5' --with-bugurl=file:///usr/share/doc/
    gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++
    --prefix=/usr --enable-shared --enable-multiarch
    --enable-linker- build-id --with-system-zlib
    --libexecdir=/usr/lib
    --without-included-gettext --enable-threads=posix
    --with-gxx-include-dir=/usr/include/c++/4.4
    --program-suffix=-4.4 --enable-nls --enable-clocale=gnu
    --enable-libstdcxx-debug -
    ...

So, it should work, but doesn't seem to :(

Thanks for all the effort Doug.

-regards,
Larry