stl_multimap.h File Reference

#include <bits/concept_check.h>

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Functions
namespace std	_GLIBCXX_VISIBILITY (default)

Detailed Description

This is an internal header file, included by other library headers. Do not attempt to use it directly. {map}

Function Documentation

namespace std _GLIBCXX_VISIBILITY

(

default

)

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).

This turns a red-black tree into a [multi]map.

The actual tree structure.

Default constructor creates no elements.

Creates a multimap with no elements.

Parameters

__comp	A comparison object.
__a	An allocator object.

Multimap copy constructor.

Parameters

__x	A multimap of identical element and allocator types.

The newly-created multimap uses a copy of the allocation object used by __x.

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)).

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)).

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.

Multimap assignment operator.

Parameters

__x	A multimap of identical element and allocator types.

All the elements of __x are copied, but unlike the copy constructor, the allocator object is not copied.

Get a copy of the memory allocation object.

Returns a read/write iterator that points to the first pair in the multimap. Iteration is done in ascending order according to the keys.

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.

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.

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.

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.

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.

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.

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.

Returns true if the multimap is empty.

Returns the size of the multimap.

Returns the maximum size of the multimap.

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.

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: http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html

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

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.

Erases an element from a multimap.

Parameters

__position

An iterator pointing to the element to be erased.

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.

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.

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.

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.

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.

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.

Returns the key comparison object out of which the multimap was constructed.

Returns a value comparison object, built from the key comparison object out of which the multimap was constructed.

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.

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.

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.

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.

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().

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().

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().

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).

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).

Multimap equality comparison.

Parameters

__x	A multimap.
__y	A multimap of the same type as __x.

Returns

True iff the size and elements of the maps are equal.

This is an equivalence relation. It is linear in the size of the multimaps. Multimaps are considered equivalent if their sizes are equal, and if corresponding elements compare equal.

Multimap ordering relation.

Parameters

__x	A multimap.
__y	A multimap of the same type as __x.

Returns

True iff x is lexicographically less than y.

This is a total ordering relation. It is linear in the size of the multimaps. The elements must be comparable with <.

See std::lexicographical_compare() for how the determination is made.

Based on operator==

Based on operator<

Based on operator<

Based on operator<

See std::multimap::swap().

{
_GLIBCXX_BEGIN_NAMESPACE_CONTAINER

  template <typename _Key, typename _Tp,
        typename _Compare = std::less<_Key>,
        typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
    class multimap
    {
    public:
      typedef _Key                                          key_type;
      typedef _Tp                                           mapped_type;
      typedef std::pair<const _Key, _Tp>                    value_type;
      typedef _Compare                                      key_compare;
      typedef _Alloc                                        allocator_type;

    private:
      // concept requirements
      typedef typename _Alloc::value_type                   _Alloc_value_type;
      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
      __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
                _BinaryFunctionConcept)
      __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)

    public:
      class value_compare
      : public std::binary_function<value_type, value_type, bool>
      {
    friend class multimap<_Key, _Tp, _Compare, _Alloc>;
      protected:
    _Compare comp;

    value_compare(_Compare __c)
    : comp(__c) { }

      public:
    bool operator()(const value_type& __x, const value_type& __y) const
    { return comp(__x.first, __y.first); }
      };

    private:
      typedef typename _Alloc::template rebind<value_type>::other 
        _Pair_alloc_type;

      typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
               key_compare, _Pair_alloc_type> _Rep_type;
      _Rep_type _M_t;

    public:
      // many of these are specified differently in ISO, but the following are
      // "functionally equivalent"
      typedef typename _Pair_alloc_type::pointer         pointer;
      typedef typename _Pair_alloc_type::const_pointer   const_pointer;
      typedef typename _Pair_alloc_type::reference       reference;
      typedef typename _Pair_alloc_type::const_reference const_reference;
      typedef typename _Rep_type::iterator               iterator;
      typedef typename _Rep_type::const_iterator         const_iterator;
      typedef typename _Rep_type::size_type              size_type;
      typedef typename _Rep_type::difference_type        difference_type;
      typedef typename _Rep_type::reverse_iterator       reverse_iterator;
      typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;

      // [23.3.2] construct/copy/destroy
      // (get_allocator() is also listed in this section)
      multimap()
      : _M_t() { }

      explicit
      multimap(const _Compare& __comp,
           const allocator_type& __a = allocator_type())
      : _M_t(__comp, _Pair_alloc_type(__a)) { }

      multimap(const multimap& __x)
      : _M_t(__x._M_t) { }

#if __cplusplus >= 201103L

      multimap(multimap&& __x)
      noexcept(is_nothrow_copy_constructible<_Compare>::value)
      : _M_t(std::move(__x._M_t)) { }

      multimap(initializer_list<value_type> __l,
           const _Compare& __comp = _Compare(),
           const allocator_type& __a = allocator_type())
      : _M_t(__comp, _Pair_alloc_type(__a))
      { _M_t._M_insert_equal(__l.begin(), __l.end()); }
#endif

      template<typename _InputIterator>
        multimap(_InputIterator __first, _InputIterator __last)
    : _M_t()
        { _M_t._M_insert_equal(__first, __last); }

      template<typename _InputIterator>
        multimap(_InputIterator __first, _InputIterator __last,
         const _Compare& __comp,
         const allocator_type& __a = allocator_type())
    : _M_t(__comp, _Pair_alloc_type(__a))
        { _M_t._M_insert_equal(__first, __last); }

      // FIXME There is no dtor declared, but we should have something generated
      // by Doxygen.  I don't know what tags to add to this paragraph to make
      // that happen:
      multimap&
      operator=(const multimap& __x)
      {
    _M_t = __x._M_t;
    return *this;
      }

#if __cplusplus >= 201103L

      multimap&
      operator=(multimap&& __x)
      {
    // NB: DR 1204.
    // NB: DR 675.
    this->clear();
    this->swap(__x);
    return *this;
      }

      multimap&
      operator=(initializer_list<value_type> __l)
      {
    this->clear();
    this->insert(__l.begin(), __l.end());
    return *this;
      }
#endif

      allocator_type
      get_allocator() const _GLIBCXX_NOEXCEPT 
      { return allocator_type(_M_t.get_allocator()); }

      // iterators
      iterator
      begin() _GLIBCXX_NOEXCEPT
      { return _M_t.begin(); }

      const_iterator
      begin() const _GLIBCXX_NOEXCEPT
      { return _M_t.begin(); }

      iterator
      end() _GLIBCXX_NOEXCEPT
      { return _M_t.end(); }

      const_iterator
      end() const _GLIBCXX_NOEXCEPT
      { return _M_t.end(); }

      reverse_iterator
      rbegin() _GLIBCXX_NOEXCEPT
      { return _M_t.rbegin(); }

      const_reverse_iterator
      rbegin() const _GLIBCXX_NOEXCEPT
      { return _M_t.rbegin(); }

      reverse_iterator
      rend() _GLIBCXX_NOEXCEPT
      { return _M_t.rend(); }

      const_reverse_iterator
      rend() const _GLIBCXX_NOEXCEPT
      { return _M_t.rend(); }

#if __cplusplus >= 201103L

      const_iterator
      cbegin() const noexcept
      { return _M_t.begin(); }

      const_iterator
      cend() const noexcept
      { return _M_t.end(); }

      const_reverse_iterator
      crbegin() const noexcept
      { return _M_t.rbegin(); }

      const_reverse_iterator
      crend() const noexcept
      { return _M_t.rend(); }
#endif

      // capacity
      bool
      empty() const _GLIBCXX_NOEXCEPT
      { return _M_t.empty(); }

      size_type
      size() const _GLIBCXX_NOEXCEPT
      { return _M_t.size(); }

      size_type
      max_size() const _GLIBCXX_NOEXCEPT
      { return _M_t.max_size(); }

      // modifiers
#if __cplusplus >= 201103L

      template<typename... _Args>
    iterator
    emplace(_Args&&... __args)
    { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); }

      template<typename... _Args>
    iterator
    emplace_hint(const_iterator __pos, _Args&&... __args)
    {
      return _M_t._M_emplace_hint_equal(__pos,
                        std::forward<_Args>(__args)...);
    }
#endif

      iterator
      insert(const value_type& __x)
      { return _M_t._M_insert_equal(__x); }

#if __cplusplus >= 201103L
      template<typename _Pair, typename = typename
           std::enable_if<std::is_constructible<value_type,
                            _Pair&&>::value>::type>
        iterator
        insert(_Pair&& __x)
        { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); }
#endif

      iterator
#if __cplusplus >= 201103L
      insert(const_iterator __position, const value_type& __x)
#else
      insert(iterator __position, const value_type& __x)
#endif
      { return _M_t._M_insert_equal_(__position, __x); }

#if __cplusplus >= 201103L
      template<typename _Pair, typename = typename
           std::enable_if<std::is_constructible<value_type,
                            _Pair&&>::value>::type>
        iterator
        insert(const_iterator __position, _Pair&& __x)
        { return _M_t._M_insert_equal_(__position,
                       std::forward<_Pair>(__x)); }
#endif

      template<typename _InputIterator>
        void
        insert(_InputIterator __first, _InputIterator __last)
        { _M_t._M_insert_equal(__first, __last); }

#if __cplusplus >= 201103L

      void
      insert(initializer_list<value_type> __l)
      { this->insert(__l.begin(), __l.end()); }
#endif

#if __cplusplus >= 201103L
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      iterator
      erase(const_iterator __position)
      { return _M_t.erase(__position); }

      // LWG 2059.
      _GLIBCXX_ABI_TAG_CXX11
      iterator
      erase(iterator __position)
      { return _M_t.erase(__position); }
#else

      void
      erase(iterator __position)
      { _M_t.erase(__position); }
#endif

      size_type
      erase(const key_type& __x)
      { return _M_t.erase(__x); }

#if __cplusplus >= 201103L
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      iterator
      erase(const_iterator __first, const_iterator __last)
      { return _M_t.erase(__first, __last); }
#else
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 130. Associative erase should return an iterator.
      void
      erase(iterator __first, iterator __last)
      { _M_t.erase(__first, __last); }
#endif

      void
      swap(multimap& __x)
      { _M_t.swap(__x._M_t); }

      void
      clear() _GLIBCXX_NOEXCEPT
      { _M_t.clear(); }

      // observers
      key_compare
      key_comp() const
      { return _M_t.key_comp(); }

      value_compare
      value_comp() const
      { return value_compare(_M_t.key_comp()); }

      // multimap operations
      iterator
      find(const key_type& __x)
      { return _M_t.find(__x); }

      const_iterator
      find(const key_type& __x) const
      { return _M_t.find(__x); }

      size_type
      count(const key_type& __x) const
      { return _M_t.count(__x); }

      iterator
      lower_bound(const key_type& __x)
      { return _M_t.lower_bound(__x); }

      const_iterator
      lower_bound(const key_type& __x) const
      { return _M_t.lower_bound(__x); }

      iterator
      upper_bound(const key_type& __x)
      { return _M_t.upper_bound(__x); }

      const_iterator
      upper_bound(const key_type& __x) const
      { return _M_t.upper_bound(__x); }

      std::pair<iterator, iterator>
      equal_range(const key_type& __x)
      { return _M_t.equal_range(__x); }

      std::pair<const_iterator, const_iterator>
      equal_range(const key_type& __x) const
      { return _M_t.equal_range(__x); }

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

      template<typename _K1, typename _T1, typename _C1, typename _A1>
        friend bool
        operator<(const multimap<_K1, _T1, _C1, _A1>&,
          const multimap<_K1, _T1, _C1, _A1>&);
  };

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return __x._M_t == __y._M_t; }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
              const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return __x._M_t < __y._M_t; }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return !(__x == __y); }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
              const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return __y < __x; }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return !(__y < __x); }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline bool
    operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
               const multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { return !(__x < __y); }

  template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
    inline void
    swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x,
         multimap<_Key, _Tp, _Compare, _Alloc>& __y)
    { __x.swap(__y); }

_GLIBCXX_END_NAMESPACE_CONTAINER
} // namespace std