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

[François Dumont]

On 31/05/2017 12:34, Jonathan Wakely wrote:
>
> Well in general the is_nothrow_default_constructible trait also tells
> you if the type is default-constructible at all, but the form above
> won't compile if it isn't default-constructible. In this specific case
> it doesn't matter, because that constructor won't compile anyway if
> the allocator isn't default-constructible.
>

Thanks for explanation, for the moment I kept the noexcept calls. You'll 
tell me if it is fine in this new proposal.

>>    I'll complete testing and add a test on this value-initialization 
>> before commit if you agree.

So here is the new proposal with the additional test.

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.

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 ?

Now I wonder if I really introduced a regression in rb_tree...

Tested under Linux x86_64.

     * include/bits/stl_bvector.h
     (__fill_bvector(_Bit_type*, unsigned int, unsigned int, bool)):
     Change signature.
     (std::fill(_Bit_iterator, _Bit_iterator, bool)): Adapt.
     (_Bvector_impl_data): New.
     (_Bvector_impl): Inherits from latter.
     (_Bvector_impl(_Bit_alloc_type&&)): Delete.
     (_Bvector_impl(_Bvector_impl&&)): New, default.
     (_Bvector_base()): Default.
     (_Bvector_base(_Bvector_base&&)): Default.
     (_Bvector_base::_M_move_data(_Bvector_base&&)): New.
     (vector(vector&&, const allocator_type&)): Use latter.
     (vector<bool>::operator=(vector&&)): Likewise.
     (vector<bool>::vector()): Default.
     (vector<bool>::assign(_InputIterator, _InputIterator)): Use
     _M_assign_aux.
     (vector<bool>::assign(initializer_list<bool>)): Likewise.
     (vector<bool>::_M_initialize_value(bool)): New.
     (vector<bool>(size_type, const bool&, const allocator_type&)): Use
     latter.
     (vector<bool>::_M_initialize_dispatch(_Integer, _Integer, 
__true_type)):
     Likewise.
     (vector<bool>::_M_fill_assign(size_t, bool)): Likewise.

Ok to commit ?

François
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bvector.patch
Type: text/x-patch
Size: 13128 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20170531/036725f7/attachment.bin>