std::forward_list optim for always equal allocator

[Daniel Krügler]

2017-07-17 22:10 GMT+02:00 François Dumont <frs.dumont@gmail.com>:
> Hi
>
>     Here is the patch to implement the always equal alloc optimization for
> forward_list. With this version there is no abi issue.
>
>     I also prefer to implement the _Fwd_list_node_base move operator for
> consistency with the move constructor and used it where applicable.
>
>
>     * include/bits/forward_list.h
>     (_Fwd_list_node_base& operator=(_Fwd_list_node_base&&)): Implement.
>     (_Fwd_list_impl(_Fwd_list_impl&&, _Node_alloc_type&&)): New.
>     (_Fwd_list_base(_Fwd_list_base&&, _Node_alloc_type&&, std::true_type)):
>     New, use latter.
>     (forward_list(forward_list&&, _Node_alloc_type&&, std::false_type)):
>     New.
>     (forward_list(forward_list&&, _Node_alloc_type&&, std::true_type)):
>     New.
>     (forward_list(forward_list&&, const _Alloc&)): Adapt to use latters.
>     * include/bits/forward_list.tcc
>     (_Fwd_list_base(_Fwd_list_base&&, _Node_alloc_type&&)): Adapt to use
>     _M_impl._M_head move assignment.
>     (forward_list<>::merge(forward_list<>&&, _Comp)): Likewise.
>
> Tested under Linux x86_64, ok to commit ?

Out of curiosity: Shouldn't

_Fwd_list_node_base&
operator=(_Fwd_list_node_base&& __x);

be declared noexcept?

Thanks,

- Daniel