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

[Jonathan Wakely]

On 15/05/17 19:57 +0200, François Dumont wrote:
>Hi
>
>    Following what I have started on RbTree here is a patch to default 
>implementation of default and move constructors on std::vector<bool>.
>
>    As in _Rb_tree_impl the default allocator is not value initialized 
>anymore. We could add a small helper type arround the allocator to do 
>this value initialization per default. Should I do so ?

It's required to be value-initialized, so if your patch changes that
then it's a problem.

Did we decide it's OK to do that for RB-trees? Did we actually discuss
that part of the r243379 changes?

N.B. defining these members as defaulted makes diagnostics worse, see
PR 80858, but I think we need to fix that in the compiler anyway.