Re: Default std::vector<bool> default and move constructor

[Jonathan Wakely <jwakely at redhat dot com>]

On 01/06/17 22:49 +0200, François Dumont wrote:
> On 01/06/2017 15:34, Jonathan Wakely wrote:
> > On 31/05/17 22:28 +0200, François Dumont wrote:
> > > Unless I made a mistake it revealed that restoring explicit call 
> > > to _Bit_alloc_type() in default constructor was not enough. G++ 
> > > doesn't transform it into a value-init if needed. I don't know if 
> > > it is a compiler bug but I had to do just like presented in the 
> > > Standard to achieve the expected behavior.
> >
> > That really shouldn't be necessary (see blow).
> >
> > > This value-init is specific to post-C++11 right ? Maybe I could 
> > > remove the useless explicit call to _Bit_alloc_type() in pre-C++11 
> > > mode ?
> >
> > No, because C++03 also requires the allocator to be value-initialized.
>
> Ok so I'll try to make the test C++03 compatible.

That would require a much more complicated allocator, so I don't think
it's too important.

If you define the constructor like:

     _Bvector_impl()
     _GLIBCXX_NOEXCEPT_IF( noexcept(_Bit_alloc_type()) )
     : _Bit_alloc_type()
     { }

then it will do the same thing for C++03 as for later versions, so
testing for C++11 only should be good enough.