Provided by: libstdc++-9-doc_9.5.0-1ubuntu1~22.04_all bug

NAME

       std::multimap< _Key, _Tp, _Compare, _Alloc > - A standard container made up of (key,value)
       pairs, which can be retrieved based on a key, in logarithmic time.

SYNOPSIS

   Public Types
       typedef _Alloc allocator_type
       typedef _Rep_type::const_iterator const_iterator
       typedef _Alloc_traits::const_pointer const_pointer
       typedef _Alloc_traits::const_reference const_reference
       typedef _Rep_type::const_reverse_iterator const_reverse_iterator
       typedef _Rep_type::difference_type difference_type
       typedef _Rep_type::iterator iterator
       typedef _Compare key_compare
       typedef _Key key_type
       typedef _Tp mapped_type
       typedef _Alloc_traits::pointer pointer
       typedef _Alloc_traits::reference reference
       typedef _Rep_type::reverse_iterator reverse_iterator
       typedef _Rep_type::size_type size_type
       typedef std::pair< const _Key, _Tp > value_type

   Public Member Functions
       multimap ()=default
           Default constructor creates no elements.
       template<typename _InputIterator > multimap (_InputIterator __first, _InputIterator
           __last)
           Builds a multimap from a range.
       template<typename _InputIterator > multimap (_InputIterator __first, _InputIterator
           __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
           Builds a multimap from a range.
       template<typename _InputIterator > multimap (_InputIterator __first, _InputIterator
           __last, const allocator_type &__a)
           Allocator-extended range constructor.
       multimap (const _Compare &__comp, const allocator_type &__a=allocator_type())
           Creates a multimap with no elements.
       multimap (const allocator_type &__a)
           Allocator-extended default constructor.
       multimap (const multimap &)=default
           Multimap copy constructor.
       multimap (const multimap &__m, const allocator_type &__a)
           Allocator-extended copy constructor.
       multimap (initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const
           allocator_type &__a=allocator_type())
           Builds a multimap from an initializer_list.
       multimap (initializer_list< value_type > __l, const allocator_type &__a)
           Allocator-extended initialier-list constructor.
       multimap (multimap &&)=default
           Multimap move constructor.
       multimap (multimap &&__m, const allocator_type &__a)
           noexcept(is_nothrow_copy_constructible< _Compare >::value
           &&_Alloc_traits::_S_always_equal())
           Allocator-extended move constructor.
       ~multimap ()=default
       const_iterator begin () const noexcept
       iterator begin () noexcept
       const_iterator cbegin () const noexcept
       const_iterator cend () const noexcept
       void clear () noexcept
       const_reverse_iterator crbegin () const noexcept
       const_reverse_iterator crend () const noexcept
       template<typename... _Args> iterator emplace (_Args &&... __args)
           Build and insert a std::pair into the multimap.
       template<typename... _Args> iterator emplace_hint (const_iterator __pos, _Args &&...
           __args)
           Builds and inserts a std::pair into the multimap.
       _GLIBCXX_NODISCARD bool empty () const noexcept
       const_iterator end () const noexcept
       iterator end () noexcept
       size_type erase (const key_type &__x)
           Erases elements according to the provided key.
       iterator erase (const_iterator __first, const_iterator __last)
           Erases a [first,last) range of elements from a multimap.
       allocator_type get_allocator () const noexcept
           Get a copy of the memory allocation object.
       template<typename _InputIterator > void insert (_InputIterator __first, _InputIterator
           __last)
           A template function that attempts to insert a range of elements.
       void insert (initializer_list< value_type > __l)
           Attempts to insert a list of std::pairs into the multimap.
       key_compare key_comp () const
       size_type max_size () const noexcept
       multimap & operator= (const multimap &)=default
           Multimap assignment operator.
       multimap & operator= (initializer_list< value_type > __l)
           Multimap list assignment operator.
       multimap & operator= (multimap &&)=default
           Move assignment operator.
       const_reverse_iterator rbegin () const noexcept
       reverse_iterator rbegin () noexcept
       const_reverse_iterator rend () const noexcept
       reverse_iterator rend () noexcept
       size_type size () const noexcept
       void swap (multimap &__x) noexcept(/*conditional */)
           Swaps data with another multimap.
       value_compare value_comp () const

           iterator insert (const value_type &__x)
               Inserts a std::pair into the multimap.
           iterator insert (value_type &&__x)
               Inserts a std::pair into the multimap.
           template<typename _Pair > __enable_if_t< is_constructible< value_type, _Pair >::value,
               iterator > insert (_Pair &&__x)
               Inserts a std::pair into the multimap.

           iterator insert (const_iterator __position, const value_type &__x)
               Inserts a std::pair into the multimap.
           iterator insert (const_iterator __position, value_type &&__x)
               Inserts a std::pair into the multimap.
           template<typename _Pair > __enable_if_t< is_constructible< value_type, _Pair &&
               >::value, iterator > insert (const_iterator __position, _Pair &&__x)
               Inserts a std::pair into the multimap.

           iterator erase (const_iterator __position)
               Erases an element from a multimap.
           _GLIBCXX_ABI_TAG_CXX11 iterator erase (iterator __position)
               Erases an element from a multimap.

           iterator find (const key_type &__x)
               Tries to locate an element in a multimap.
           template<typename _Kt > auto find (const _Kt &__x) -> decltype(_M_t._M_find_tr(__x))
               Tries to locate an element in a multimap.

           const_iterator find (const key_type &__x) const
               Tries to locate an element in a multimap.
           template<typename _Kt > auto find (const _Kt &__x) const ->
               decltype(_M_t._M_find_tr(__x))
               Tries to locate an element in a multimap.

           size_type count (const key_type &__x) const
               Finds the number of elements with given key.
           template<typename _Kt > auto count (const _Kt &__x) const ->
               decltype(_M_t._M_count_tr(__x))
               Finds the number of elements with given key.

           iterator lower_bound (const key_type &__x)
               Finds the beginning of a subsequence matching given key.
           template<typename _Kt > auto lower_bound (const _Kt &__x) ->
               decltype(iterator(_M_t._M_lower_bound_tr(__x)))
               Finds the beginning of a subsequence matching given key.

           const_iterator lower_bound (const key_type &__x) const
               Finds the beginning of a subsequence matching given key.
           template<typename _Kt > auto lower_bound (const _Kt &__x) const ->
               decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
               Finds the beginning of a subsequence matching given key.

           iterator upper_bound (const key_type &__x)
               Finds the end of a subsequence matching given key.
           template<typename _Kt > auto upper_bound (const _Kt &__x) ->
               decltype(iterator(_M_t._M_upper_bound_tr(__x)))
               Finds the end of a subsequence matching given key.

           const_iterator upper_bound (const key_type &__x) const
               Finds the end of a subsequence matching given key.
           template<typename _Kt > auto upper_bound (const _Kt &__x) const ->
               decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
               Finds the end of a subsequence matching given key.

           std::pair< iterator, iterator > equal_range (const key_type &__x)
               Finds a subsequence matching given key.
           template<typename _Kt > auto equal_range (const _Kt &__x) -> decltype(pair< iterator,
               iterator >(_M_t._M_equal_range_tr(__x)))
               Finds a subsequence matching given key.

           std::pair< const_iterator, const_iterator > equal_range (const key_type &__x) const
               Finds a subsequence matching given key.
           template<typename _Kt > auto equal_range (const _Kt &__x) const -> decltype(pair<
               const_iterator, const_iterator >(_M_t._M_equal_range_tr(__x)))
               Finds a subsequence matching given key.

   Friends
       template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > bool operator< (const
           multimap< _K1, _T1, _C1, _A1 > &, const multimap< _K1, _T1, _C1, _A1 > &)
       template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > bool operator==
           (const multimap< _K1, _T1, _C1, _A1 > &, const multimap< _K1, _T1, _C1, _A1 > &)

Detailed Description

   template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc =
       std::allocator<std::pair<const _Key, _Tp> >>
       class std::multimap< _Key, _Tp, _Compare, _Alloc >" A standard container made up of
       (key,value) pairs, which can be retrieved based on a key, in logarithmic time.

       Template Parameters
           _Key Type of key objects.
           _Tp Type of mapped objects.
           _Compare Comparison function object type, defaults to less<_Key>.
           _Alloc Allocator type, defaults to allocator<pair<const _Key, _Tp>.

       Meets the requirements of a container, a reversible container, and an associative
       container (using equivalent keys). For a multimap<Key,T> the key_type is Key, the
       mapped_type is T, and the value_type is std::pair<const Key,T>.

       Multimaps support bidirectional iterators.

       The private tree data is declared exactly the same way for map and multimap; the
       distinction is made entirely in how the tree functions are called (*_unique versus
       *_equal, same as the standard).

       Definition at line 99 of file stl_multimap.h.

Constructor & Destructor Documentation

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap () [default]
       Default constructor creates no elements.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (const _Compare & __comp, const allocator_type & __a = allocator_type())
       [inline],  [explicit]
       Creates a multimap with no elements.

       Parameters
           __comp A comparison object.
           __a An allocator object.

       Definition at line 189 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (const multimap< _Key, _Tp, _Compare, _Alloc > &) [default]
       Multimap copy constructor. Whether the allocator is copied depends on the allocator
       traits.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (multimap< _Key, _Tp, _Compare, _Alloc > &&) [default]
       Multimap move constructor. The newly-created multimap contains the exact contents of the
       moved instance. The moved instance is a valid, but unspecified multimap.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (initializer_list< value_type > __l, const _Compare & __comp = _Compare(),
       const allocator_type & __a = allocator_type()) [inline]
       Builds a multimap from an initializer_list.

       Parameters
           __l An initializer_list.
           __comp A comparison functor.
           __a An allocator object.

       Create a multimap consisting of copies of the elements from the initializer_list. This is
       linear in N if the list is already sorted, and NlogN otherwise (where N is __l.size()).

       Definition at line 223 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (const allocator_type & __a) [inline],  [explicit]
       Allocator-extended default constructor.

       Definition at line 231 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (const multimap< _Key, _Tp, _Compare, _Alloc > & __m, const allocator_type &
       __a) [inline]
       Allocator-extended copy constructor.

       Definition at line 235 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (multimap< _Key, _Tp, _Compare, _Alloc > && __m, const allocator_type & __a)
       [inline],  [noexcept]
       Allocator-extended move constructor.

       Definition at line 239 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::multimap (initializer_list< value_type > __l, const allocator_type & __a) [inline]
       Allocator-extended initialier-list constructor.

       Definition at line 245 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator >
       std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap (_InputIterator __first,
       _InputIterator __last, const allocator_type & __a) [inline]
       Allocator-extended range constructor.

       Definition at line 251 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator >
       std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap (_InputIterator __first,
       _InputIterator __last) [inline]
       Builds a multimap from a range.

       Parameters
           __first An input iterator.
           __last An input iterator.

       Create a multimap consisting of copies of the elements from [__first,__last). This is
       linear in N if the range is already sorted, and NlogN otherwise (where N is
       distance(__first,__last)).

       Definition at line 267 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator >
       std::multimap< _Key, _Tp, _Compare, _Alloc >::multimap (_InputIterator __first,
       _InputIterator __last, const _Compare & __comp, const allocator_type & __a =
       allocator_type()) [inline]
       Builds a multimap from a range.

       Parameters
           __first An input iterator.
           __last An input iterator.
           __comp A comparison functor.
           __a An allocator object.

       Create a multimap consisting of copies of the elements from [__first,__last). This is
       linear in N if the range is already sorted, and NlogN otherwise (where N is
       distance(__first,__last)).

       Definition at line 283 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::multimap< _Key, _Tp, _Compare, _Alloc
       >::~multimap () [default]
       The dtor only erases the elements, and note that if the elements themselves are pointers,
       the pointed-to memory is not touched in any way. Managing the pointer is the user's
       responsibility.

Member Function Documentation

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::begin () const [inline],  [noexcept]
       Returns a read-only (constant) iterator that points to the first pair in the multimap.
       Iteration is done in ascending order according to the keys.

       Definition at line 358 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::begin () [inline],  [noexcept]
       Returns a read/write iterator that points to the first pair in the multimap. Iteration is
       done in ascending order according to the keys.

       Definition at line 349 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::cbegin () const [inline],  [noexcept]
       Returns a read-only (constant) iterator that points to the first pair in the multimap.
       Iteration is done in ascending order according to the keys.

       Definition at line 422 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::cend () const [inline],  [noexcept]
       Returns a read-only (constant) iterator that points one past the last pair in the
       multimap. Iteration is done in ascending order according to the keys.

       Definition at line 431 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> void std::multimap< _Key, _Tp, _Compare,
       _Alloc >::clear () [inline],  [noexcept]
       Erases all elements in a multimap. Note that this function only erases the elements, and
       that if the elements themselves are pointers, the pointed-to memory is not touched in any
       way. Managing the pointer is the user's responsibility.

       Definition at line 806 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::count (const _Kt & __x) const ->
       decltype(_M_t._M_count_tr(__x))
             [inline]"

       Finds the number of elements with given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Number of elements with specified key.

       Definition at line 889 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> size_type std::multimap< _Key, _Tp,
       _Compare, _Alloc >::count (const key_type & __x) const [inline]
       Finds the number of elements with given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Number of elements with specified key.

       Definition at line 883 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::multimap< _Key,
       _Tp, _Compare, _Alloc >::crbegin () const [inline],  [noexcept]
       Returns a read-only (constant) reverse iterator that points to the last pair in the
       multimap. Iteration is done in descending order according to the keys.

       Definition at line 440 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::multimap< _Key,
       _Tp, _Compare, _Alloc >::crend () const [inline],  [noexcept]
       Returns a read-only (constant) reverse iterator that points to one before the first pair
       in the multimap. Iteration is done in descending order according to the keys.

       Definition at line 449 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> iterator
       std::multimap< _Key, _Tp, _Compare, _Alloc >::emplace (_Args &&... __args) [inline]
       Build and insert a std::pair into the multimap.

       Parameters
           __args Arguments used to generate a new pair instance (see std::piecewise_contruct for
           passing arguments to each part of the pair constructor).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function builds and inserts a (key, value) pair into the multimap. Contrary to a
       std::map the multimap does not rely on unique keys and thus multiple pairs with the same
       key can be inserted.

       Insertion requires logarithmic time.

       Definition at line 489 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> iterator
       std::multimap< _Key, _Tp, _Compare, _Alloc >::emplace_hint (const_iterator __pos, _Args
       &&... __args) [inline]
       Builds and inserts a std::pair into the multimap.

       Parameters
           __pos An iterator that serves as a hint as to where the pair should be inserted.
           __args Arguments used to generate a new pair instance (see std::piecewise_contruct for
           passing arguments to each part of the pair constructor).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted. Note that the first parameter is only a hint and can potentially improve the
       performance of the insertion process. A bad hint would cause no gains in efficiency.

       For more on hinting, see:
       https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

       Insertion requires logarithmic time (if the hint is not taken).

       Definition at line 516 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> _GLIBCXX_NODISCARD bool std::multimap<
       _Key, _Tp, _Compare, _Alloc >::empty () const [inline],  [noexcept]
       Returns true if the multimap is empty.

       Definition at line 456 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::end () const [inline],  [noexcept]
       Returns a read-only (constant) iterator that points one past the last pair in the
       multimap. Iteration is done in ascending order according to the keys.

       Definition at line 376 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::end () [inline],  [noexcept]
       Returns a read/write iterator that points one past the last pair in the multimap.
       Iteration is done in ascending order according to the keys.

       Definition at line 367 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) -> decltype(pair<iterator,
       iterator>(_M_t._M_equal_range_tr(__x)))
             [inline]"

       Finds a subsequence matching given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Pair of iterators that possibly points to the subsequence matching given key.

       This function is equivalent to

       std::make_pair(c.lower_bound(val),
                      c.upper_bound(val))

        (but is faster than making the calls separately).

       Definition at line 1024 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) const ->
       decltype(pair<const_iterator, const_iterator>(
                  _M_t._M_equal_range_tr(__x)))       [inline]"

       Finds a subsequence matching given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Pair of read-only (constant) iterators that possibly points to the subsequence
           matching given key.

       This function is equivalent to

       std::make_pair(c.lower_bound(val),
                      c.upper_bound(val))

        (but is faster than making the calls separately).

       Definition at line 1051 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::pair<iterator, iterator>
       std::multimap< _Key, _Tp, _Compare, _Alloc >::equal_range (const key_type & __x) [inline]
       Finds a subsequence matching given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Pair of iterators that possibly points to the subsequence matching given key.

       This function is equivalent to

       std::make_pair(c.lower_bound(val),
                      c.upper_bound(val))

        (but is faster than making the calls separately).

       Definition at line 1018 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> std::pair<const_iterator, const_iterator>
       std::multimap< _Key, _Tp, _Compare, _Alloc >::equal_range (const key_type & __x) const
       [inline]
       Finds a subsequence matching given key.

       Parameters
           __x Key of (key, value) pairs to be located.

       Returns
           Pair of read-only (constant) iterators that possibly points to the subsequence
           matching given key.

       This function is equivalent to

       std::make_pair(c.lower_bound(val),
                      c.upper_bound(val))

        (but is faster than making the calls separately).

       Definition at line 1045 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> size_type std::multimap< _Key, _Tp,
       _Compare, _Alloc >::erase (const key_type & __x) [inline]
       Erases elements according to the provided key.

       Parameters
           __x Key of element to be erased.

       Returns
           The number of elements erased.

       This function erases all elements located by the given key from a multimap. Note that this
       function only erases the element, and that if the element is itself a pointer, the
       pointed-to memory is not touched in any way. Managing the pointer is the user's
       responsibility.

       Definition at line 737 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::erase (const_iterator __first, const_iterator __last) [inline]
       Erases a [first,last) range of elements from a multimap.

       Parameters
           __first Iterator pointing to the start of the range to be erased.
           __last Iterator pointing to the end of the range to be erased .

       Returns
           The iterator __last.

       This function erases a sequence of elements from a multimap. Note that this function only
       erases the elements, and that if the elements themselves are pointers, the pointed-to
       memory is not touched in any way. Managing the pointer is the user's responsibility.

       Definition at line 758 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::erase (const_iterator __position) [inline]
       Erases an element from a multimap.

       Parameters
           __position An iterator pointing to the element to be erased.

       Returns
           An iterator pointing to the element immediately following position prior to the
           element being erased. If no such element exists, end() is returned.

       This function erases an element, pointed to by the given iterator, from a multimap. Note
       that this function only erases the element, and that if the element is itself a pointer,
       the pointed-to memory is not touched in any way. Managing the pointer is the user's
       responsibility.

       Definition at line 700 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> _GLIBCXX_ABI_TAG_CXX11 iterator
       std::multimap< _Key, _Tp, _Compare, _Alloc >::erase (iterator __position) [inline]
       Erases an element from a multimap.

       Parameters
           __position An iterator pointing to the element to be erased.

       Returns
           An iterator pointing to the element immediately following position prior to the
           element being erased. If no such element exists, end() is returned.

       This function erases an element, pointed to by the given iterator, from a multimap. Note
       that this function only erases the element, and that if the element is itself a pointer,
       the pointed-to memory is not touched in any way. Managing the pointer is the user's
       responsibility.

       Definition at line 706 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) -> decltype(_M_t._M_find_tr(__x))
             [inline]"

       Tries to locate an element in a multimap.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to sought-after element, or end() if not found.

       This function takes a key and tries to locate the element with which the key matches. If
       successful the function returns an iterator pointing to the sought after pair. If
       unsuccessful it returns the past-the-end ( end() ) iterator.

       Definition at line 847 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) const ->
       decltype(_M_t._M_find_tr(__x))
             [inline]"

       Tries to locate an element in a multimap.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to sought-after element, or end() if not found.

       This function takes a key and tries to locate the element with which the key matches. If
       successful the function returns a constant iterator pointing to the sought after pair. If
       unsuccessful it returns the past-the-end ( end() ) iterator.

       Definition at line 871 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::find (const key_type & __x) [inline]
       Tries to locate an element in a multimap.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to sought-after element, or end() if not found.

       This function takes a key and tries to locate the element with which the key matches. If
       successful the function returns an iterator pointing to the sought after pair. If
       unsuccessful it returns the past-the-end ( end() ) iterator.

       Definition at line 841 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::find (const key_type & __x) const [inline]
       Tries to locate an element in a multimap.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to sought-after element, or end() if not found.

       This function takes a key and tries to locate the element with which the key matches. If
       successful the function returns a constant iterator pointing to the sought after pair. If
       unsuccessful it returns the past-the-end ( end() ) iterator.

       Definition at line 865 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> allocator_type std::multimap< _Key, _Tp,
       _Compare, _Alloc >::get_allocator () const [inline],  [noexcept]
       Get a copy of the memory allocation object.

       Definition at line 339 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > void
       std::multimap< _Key, _Tp, _Compare, _Alloc >::insert (_InputIterator __first,
       _InputIterator __last) [inline]
       A template function that attempts to insert a range of elements.

       Parameters
           __first Iterator pointing to the start of the range to be inserted.
           __last Iterator pointing to the end of the range.

       Complexity similar to that of the range constructor.

       Definition at line 611 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Pair >
       __enable_if_t<is_constructible<value_type, _Pair>::value, iterator> std::multimap< _Key,
       _Tp, _Compare, _Alloc >::insert (_Pair && __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted.

       Insertion requires logarithmic time.

       Definition at line 549 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::insert (const value_type & __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted.

       Insertion requires logarithmic time.

       Definition at line 537 of file stl_multimap.h.

       Referenced by std::multimap< _Key, _Tp, _Compare, _Alloc >::insert().

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Pair >
       __enable_if_t<is_constructible<value_type, _Pair&&>::value, iterator> std::multimap< _Key,
       _Tp, _Compare, _Alloc >::insert (const_iterator __position, _Pair && __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __position An iterator that serves as a hint as to where the pair should be inserted.
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted. Note that the first parameter is only a hint and can potentially improve the
       performance of the insertion process. A bad hint would cause no gains in efficiency.

       For more on hinting, see:
       https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

       Insertion requires logarithmic time (if the hint is not taken).

       Definition at line 592 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::insert (const_iterator __position, const value_type & __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __position An iterator that serves as a hint as to where the pair should be inserted.
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted. Note that the first parameter is only a hint and can potentially improve the
       performance of the insertion process. A bad hint would cause no gains in efficiency.

       For more on hinting, see:
       https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

       Insertion requires logarithmic time (if the hint is not taken).

       Definition at line 577 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::insert (const_iterator __position, value_type && __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __position An iterator that serves as a hint as to where the pair should be inserted.
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted. Note that the first parameter is only a hint and can potentially improve the
       performance of the insertion process. A bad hint would cause no gains in efficiency.

       For more on hinting, see:
       https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints

       Insertion requires logarithmic time (if the hint is not taken).

       Definition at line 587 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> void std::multimap< _Key, _Tp, _Compare,
       _Alloc >::insert (initializer_list< value_type > __l) [inline]
       Attempts to insert a list of std::pairs into the multimap.

       Parameters
           __l A std::initializer_list<value_type> of pairs to be inserted.

       Complexity similar to that of the range constructor.

       Definition at line 623 of file stl_multimap.h.

       References std::multimap< _Key, _Tp, _Compare, _Alloc >::insert().

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::insert (value_type && __x) [inline]
       Inserts a std::pair into the multimap.

       Parameters
           __x Pair to be inserted (see std::make_pair for easy creation of pairs).

       Returns
           An iterator that points to the inserted (key,value) pair.

       This function inserts a (key, value) pair into the multimap. Contrary to a std::map the
       multimap does not rely on unique keys and thus multiple pairs with the same key can be
       inserted.

       Insertion requires logarithmic time.

       Definition at line 544 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> key_compare std::multimap< _Key, _Tp,
       _Compare, _Alloc >::key_comp () const [inline]
       Returns the key comparison object out of which the multimap was constructed.

       Definition at line 815 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) ->
       decltype(iterator(_M_t._M_lower_bound_tr(__x)))
             [inline]"

       Finds the beginning of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to first element equal to or greater than key, or end().

       This function returns the first element of a subsequence of elements that matches the
       given key. If unsuccessful it returns an iterator pointing to the first element that has a
       greater value than given key or end() if no such element exists.

       Definition at line 932 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) const ->
       decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
             [inline]"

       Finds the beginning of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to first element equal to or greater than key,
           or end().

       This function returns the first element of a subsequence of elements that matches the
       given key. If unsuccessful the iterator will point to the next greatest element or, if no
       such greater element exists, to end().

       Definition at line 957 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::lower_bound (const key_type & __x) [inline]
       Finds the beginning of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to first element equal to or greater than key, or end().

       This function returns the first element of a subsequence of elements that matches the
       given key. If unsuccessful it returns an iterator pointing to the first element that has a
       greater value than given key or end() if no such element exists.

       Definition at line 926 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::lower_bound (const key_type & __x) const [inline]
       Finds the beginning of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to first element equal to or greater than key,
           or end().

       This function returns the first element of a subsequence of elements that matches the
       given key. If unsuccessful the iterator will point to the next greatest element or, if no
       such greater element exists, to end().

       Definition at line 951 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> size_type std::multimap< _Key, _Tp,
       _Compare, _Alloc >::max_size () const [inline],  [noexcept]
       Returns the maximum size of the multimap.

       Definition at line 466 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> multimap& std::multimap< _Key, _Tp,
       _Compare, _Alloc >::operator= (const multimap< _Key, _Tp, _Compare, _Alloc > &) [default]
       Multimap assignment operator. Whether the allocator is copied depends on the allocator
       traits.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> multimap& std::multimap< _Key, _Tp,
       _Compare, _Alloc >::operator= (initializer_list< value_type > __l) [inline]
       Multimap list assignment operator.

       Parameters
           __l An initializer_list.

       This function fills a multimap with copies of the elements in the initializer list __l.

       Note that the assignment completely changes the multimap and that the resulting multimap's
       size is the same as the number of elements assigned.

       Definition at line 330 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> multimap& std::multimap< _Key, _Tp,
       _Compare, _Alloc >::operator= (multimap< _Key, _Tp, _Compare, _Alloc > &&) [default]
       Move assignment operator.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::multimap< _Key,
       _Tp, _Compare, _Alloc >::rbegin () const [inline],  [noexcept]
       Returns a read-only (constant) reverse iterator that points to the last pair in the
       multimap. Iteration is done in descending order according to the keys.

       Definition at line 394 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::rbegin () [inline],  [noexcept]
       Returns a read/write reverse iterator that points to the last pair in the multimap.
       Iteration is done in descending order according to the keys.

       Definition at line 385 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::multimap< _Key,
       _Tp, _Compare, _Alloc >::rend () const [inline],  [noexcept]
       Returns a read-only (constant) reverse iterator that points to one before the first pair
       in the multimap. Iteration is done in descending order according to the keys.

       Definition at line 412 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::rend () [inline],  [noexcept]
       Returns a read/write reverse iterator that points to one before the first pair in the
       multimap. Iteration is done in descending order according to the keys.

       Definition at line 403 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> size_type std::multimap< _Key, _Tp,
       _Compare, _Alloc >::size () const [inline],  [noexcept]
       Returns the size of the multimap.

       Definition at line 461 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> void std::multimap< _Key, _Tp, _Compare,
       _Alloc >::swap (multimap< _Key, _Tp, _Compare, _Alloc > & __x) [inline],  [noexcept]
       Swaps data with another multimap.

       Parameters
           __x A multimap of the same element and allocator types.

       This exchanges the elements between two multimaps in constant time. (It is only swapping a
       pointer, an integer, and an instance of the Compare type (which itself is often stateless
       and empty), so it should be quite fast.) Note that the global std::swap() function is
       specialized such that std::swap(m1,m2) will feed to this function.

       Whether the allocators are swapped depends on the allocator traits.

       Definition at line 795 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) ->
       decltype(iterator(_M_t._M_upper_bound_tr(__x)))
             [inline]"

       Finds the end of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to the first element greater than key, or end().

       Definition at line 977 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::multimap<
       _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) const ->
       decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
             [inline]"

       Finds the end of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to first iterator greater than key, or end().

       Definition at line 997 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::upper_bound (const key_type & __x) [inline]
       Finds the end of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Iterator pointing to the first element greater than key, or end().

       Definition at line 971 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::multimap< _Key, _Tp,
       _Compare, _Alloc >::upper_bound (const key_type & __x) const [inline]
       Finds the end of a subsequence matching given key.

       Parameters
           __x Key of (key, value) pair to be located.

       Returns
           Read-only (constant) iterator pointing to first iterator greater than key, or end().

       Definition at line 991 of file stl_multimap.h.

   template<typename _Key , typename _Tp , typename _Compare  = std::less<_Key>, typename _Alloc
       = std::allocator<std::pair<const _Key, _Tp> >> value_compare std::multimap< _Key, _Tp,
       _Compare, _Alloc >::value_comp () const [inline]
       Returns a value comparison object, built from the key comparison object out of which the
       multimap was constructed.

       Definition at line 823 of file stl_multimap.h.

Author

       Generated automatically by Doxygen for libstdc++ from the source code.

libstdc++                                Tue Justd::multimap< _Key, _Tp, _Compare, _Alloc >(3cxx)