Forward list default default and move constructors

[François Dumont]

Hello

     Any feedback regarding this patch ?

Thanks,
François

On 19/06/2017 22:48, François Dumont wrote:
> Hi
>
>     Here is the patch to default the default and move constructors on 
> the std::forward_list. Putting a move constructor on 
> _Fwd_list_node_base helped limiting the code impact of this patch. It 
> doesn't have any side effect as iterator types using this base type 
> are not defining any move semantic.
>
>     I also took the time to optimize the move constructor with 
> allocator when allocator is always equal. It avoids initializing an 
> empty forward list for nothing.
>
>     I think it is fine but could we have an abi issue because of the 
> change in forward_list.tcc ?
>
>     * include/bits/forward_list.h
>     (_Fwd_list_node_base(_Fwd_list_node_base&&)): New.
>     (_Fwd_list_impl()): Add noexcept qualification.
>     (_Fwd_list_impl(_Fwd_list_impl&&)): New, default.
>     (_Fwd_list_impl(_Fwd_list_impl&&, _Node_alloc_type&&)): New.
>     (_Fwd_list_base()): Default.
>     (_Fwd_list_base(_Fwd_list_base&&, _Node_alloc_type&&, true_type)): 
> New.
>     (_Fwd_list_base(_Fwd_list_base&&, _Node_alloc_type&&, 
> false_type)): New.
>     (_Fwd_list_base(_Fwd_list_base&& __lst, _Node_alloc_type&& __a)): Use
>     latter.
>     (_Fwd_list_base(_Fwd_list_base&&)): Default.
>     (forward_list<>()): Default.
>     (forward_list<>(forward_list&&)): Default.
>     * include/bits/forward_list.tcc
>     (_Fwd_list_base(_Fwd_list_base&&, _Node_alloc_type&&, 
> false_type)): New.
>     * testsuite/23_containers/forward_list/allocator/default_init.cc: 
> New.
>
> Tested under Linux x86_64, ok to commit ?
>
> François
>