Bug#478734: g++-4.2: refuses to compile valid C++ syntax

[Jason Kraftcheck <kraftche@cae.wisc.edu>]

Daniel Jacobowitz wrote:
> severity 478734 normal
> thanks
>
> On Wed, Apr 30, 2008 at 11:55:19AM -0500, Jason Kraftcheck wrote:
> > Severity: grave
>
> This is not grave, g++ is perfectly usable for other code.
>
> > I emmits the following  error message:
> >
> > bug.cc: In function 'int main()':
> > bug.cc:6: error: no matching function for call to 'std::vector<int, 
> >   std::allocator<int> >::swap(std::vector<int, std::allocator<int> >)'
> > /usr/include/c++/4.2/bits/stl_vector.h:728: note: candidates are: void 
> >   std::vector<_Tp, _Alloc>::swap(std::vector<_Tp, _Alloc>&) [with _Tp = 
> >   int, _Alloc = std::allocator<int>]
>
> I'm pretty sure GCC is correct to refuse this.  The result of a cast
> is an rvalue, so you can not take a reference to it.

Why can't I take a reference to an rvalue?  The temporary is guaranteed 
to exist until the completion of the function it is passed to.  Further, 
the error message doesn't indicate that g++ interpreted the argument as 
const.