Bug in GCC 4.5 c++0x version of std::list<T>::merge(&&)?

Bug in GCC 4.5 c++0x version of std::list<T>::merge(&&)?

[Benjamin Redelings I]

Hi,

It seems that many current uses of list<T>::merge( ) fail to compile 
with -std=c++0x, but I don't see a bug in bugzilla for this.  Itseems to 
result from:

list<_Tp, _Alloc>::
#ifdef __GXX_EXPERIMENTAL_CXX0X__
merge(list&& __x)
#else
merge(list& __x)
#endif

For c++0x, don't we need BOTH versions, since lvalues no longer bind to 
rvalue references, or am I missing something?

-BenRI

Re: Bug in GCC 4.5 c++0x version of std::list<T>::merge(&&)?

[Jonathan Wakely]

2009/12/8 Benjamin Redelings I:
> Hi,

Hi,
I've CC'd the libstdc++ list, please reply there instead of the gcc list.

> It seems that many current uses of list<T>::merge( ) fail to compile with
> -std=c++0x, but I don't see a bug in bugzilla for this.  Itseems to result
> from:
>
> list<_Tp, _Alloc>::
> #ifdef __GXX_EXPERIMENTAL_CXX0X__
> merge(list&& __x)
> #else
> merge(list& __x)
> #endif
>
> For c++0x, don't we need BOTH versions, since lvalues no longer bind to
> rvalue references, or am I missing something?

The WP only has:
void merge(list<T,Allocator>&& x);
template <class Compare> void merge(list<T,Allocator>&& x, Compare comp);

See http://home.roadrunner.com/~hinnant/issue_review/lwg-active.html#1133
which covers a similar issue with splice.

Jonathan

Re: Bug in GCC 4.5 c++0x version of std::list<T>::merge(&&)?

[Piotr Wyderski]

Benjamin Redelings wrote:

> since lvalues no longer bind to rvalue references

When has it changed? Could you please give
a reference to some paper/discussion about it?
I'm asking, because my C++0x-based application
stopped to compile on newer 4.5-s and one of
the problems is mentioned above -- but I thought
that it was a GCC issue, not a change in the Standard.

Best regards
Piotr Wyderski

Re: Bug in GCC 4.5 c++0x version of std::list<T>::merge(&&)?

[Paolo Carlini]

On 12/08/2009 10:54 AM, Piotr Wyderski wrote:
> When has it changed? Could you please give
> a reference to some paper/discussion about it?
>   

   http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2844.html

Just as an example...

Paolo.