[Bug libstdc++/109022] Low performance of std::map constructor for already sorted data of std::pair

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109022

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-03-06
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
For any type except the container's own type we don't use any hint for
insertion, and so it makes no difference whether the input is sorted or not:

      template<typename _InputIterator>
        __enable_if_t<__same_value_type<_InputIterator>::value>
        _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
        {
          _Alloc_node __an(*this);
          for (; __first != __last; ++__first)
            _M_insert_unique_(end(), *__first, __an);
        }

      template<typename _InputIterator>
        __enable_if_t<!__same_value_type<_InputIterator>::value>
        _M_insert_range_unique(_InputIterator __first, _InputIterator __last)
        {
          for (; __first != __last; ++__first)
            _M_emplace_unique(*__first);
        }