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

[Larry Evans]

On 02/04/11 15:45, Douglas Gregor wrote:
> 
> On Feb 4, 2011, at 11:54 AM, Larry Evans wrote:
> 
>> 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>
> 
> FWIW, I implemented this extension in Clang shortly after you posted this.
> 
> - Doug

Thanks!  Quick work.

Did `svn update` in the llvm source and then `make` in the llvm build
and now getting:

~/prog_dev/clang $ make HOW=clangxx move
/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:49:
In file included from /usr/include/c++/4.4/bits/allocator.h:48:
In file included from
/usr/include/c++/4.4/x86_64-linux-gnu/bits/c++allocator.h:34:
In file included from /usr/include/c++/4.4/ext/new_allocator.h:33:
In file included from /usr/include/c++/4.4/new:40:
In file included from /usr/include/c++/4.4/exception:148:
/usr/include/c++/4.4/exception_ptr.h:143:13: error: unknown type name
'type_info'
      const type_info*
            ^
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:
/usr/include/c++/4.4/bits/move.h:57:14: error: rvalue reference to type
'typename std::remove_reference<int &>::type'
      (aka 'int') cannot bind to lvalue of type 'int'
    { return __t; }
             ^~~
move.cpp:6:11: note: in instantiation of function template
specialization 'std::move<int &>' requested here
    int j=std::move(i);
          ^
2 errors generated.
make: *** [move] Error 1
~/prog_dev/clang $