map(C++std)

map , multimap , operator== , operator!= , operator< , operator> , operator<= , operator>= , swap - defines template classes that implement associative containers that map keys to values (standard template library)

Synopsis

   namespace std {
   template<class Key, class T, class Pred, class A>
       class map;
   template<class Key, class T, class Pred, class A>
       class multimap;

           // TEMPLATE FUNCTIONS
   template<class Key, class T, class Pred, class A>
       bool operator==(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator==(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator!=(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator!=(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator>(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator>(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<=(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<=(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator>=(
           const map<Key, T, Pred, A>& lhs,
           const map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator>=(
           const multimap<Key, T, Pred, A>& lhs,
           const multimap<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       void swap(
           map<Key, T, Pred, A>& lhs,
           map<Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       void swap(
           multimap<Key, T, Pred, A>& lhs,
           multimap<Key, T, Pred, A>& rhs);
       };

Synopsis

Include the STL standard header <map> to define the container template classes map and multimap, and their supporting templates.

map

allocator_type , begin , clear , const_iterator , const_pointer , const_reference , const_reverse_iterator , count , difference_type , empty , end , equal_range , erase , find , get_allocator , insert , iterator , key_comp , key_compare , key_type , lower_bound , map , mapped_type , max_size , operator[] , pointer , rbegin , reference , rend , reverse_iterator , size , size_type , swap , upper_bound , value_comp , value_compare , value_type

   template<class Key, class T, class Pred = less<Key>,
       class A = allocator<pair<const Key, T> > >
       class map {
   public:
       typedef Key key_type;
       typedef T mapped_type;
       typedef Pred key_compare;
       typedef A allocator_type;
       typedef pair<const Key, T> value_type;
       class value_compare;
       typedef A::pointer pointer;
       typedef A::const_pointer const_pointer;
       typedef A::reference reference;
       typedef A::const_reference const_reference;
       typedef T0 iterator;
       typedef T1 const_iterator;
       typedef T2 size_type;
       typedef T3 difference_type;
       typedef reverse_iterator<const_iterator>
           const_reverse_iterator;
       typedef reverse_iterator<iterator> reverse_iterator;
       map();
       explicit map(const Pred& comp);
       map(const Pred& comp, const A& al);
       map(const map& x);
       template<class InIt>
           map(InIt first, InIt last);
       template<class InIt>
           map(InIt first, InIt last,
               const Pred& comp);
       template<class InIt>
           map(InIt first, InIt last,
               const Pred& comp, const A& al);
       iterator begin();
       const_iterator begin() const;
       iterator end();
       const_iterator end() const;
       reverse_iterator rbegin();
       const_reverse_iterator rbegin() const;
       reverse_iterator rend();
       const_reverse_iterator rend() const;
       size_type size() const;
       size_type max_size() const;
       bool empty() const;
       A get_allocator() const;
       mapped_type operator[](const Key& key);
       pair<iterator, bool> insert(const value_type& x);
       iterator insert(iterator it, const value_type& x);
       template<class InIt>
           void insert(InIt first, InIt last);
       iterator erase(iterator it);
       iterator erase(iterator first, iterator last);
       size_type erase(const Key& key);
       void clear();
       void swap(map& x);
       key_compare key_comp() const;
       value_compare value_comp() const;
       iterator find(const Key& key);
       const_iterator find(const Key& key) const;
       size_type count(const Key& key) const;
       iterator lower_bound(const Key& key);
       const_iterator lower_bound(const Key& key) const;
       iterator upper_bound(const Key& key);
       const_iterator upper_bound(const Key& key) const;
       pair<iterator, iterator> equal_range(const Key& key);
       pair<const_iterator, const_iterator>
           equal_range(const Key& key) const;
       };

The template class describes an object that controls a varying-length sequence of elements of type pair<const Key, T>. The sequence is ordered by the predicate Pred. The first element of each pair is the sort key and the second is its associated value. The sequence is represented in a way that permits lookup, insertion, and removal of an arbitrary element with a number of operations proportional to the logarithm of the number of elements in the sequence (logarithmic time). Moreover, inserting an element invalidates no iterators, and removing an element invalidates only those iterators which point at the removed element.

The object orders the sequence it controls by calling a stored function object of type Pred. You access this stored object by calling the member function key_comp(). Such a function object must impose a total ordering on sort keys of type Key. For any element x that precedes y in the sequence, key_comp()(y.first, x.first) is false. (For the default function object less<Key>, sort keys never decrease in value.) Unlike template class multimap, an object of template class map ensures that key_comp()(x.first, y.first) is true. (Each key is unique.)

The object allocates and frees storage for the sequence it controls through a stored allocator object of class A. Such an allocator object must have the same external interface as an object of template class allocator. Note that the stored allocator object is not copied when the container object is assigned.

map::allocator_type

   typedef A allocator_type;

The type is a synonym for the template parameter A.

map::begin

   const_iterator begin() const;
   iterator begin();

The member function returns a bidirectional iterator that points at the first element of the sequence (or just beyond the end of an empty sequence).

map::clear

   void clear();

The member function calls erase( begin(), end()).

map::const_iterator

   typedef T1 const_iterator;

The type describes an object that can serve as a constant bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T1.

map::const_pointer

   typedef A::const_pointer const_pointer;

The type describes an object that can serve as a constant pointer to an element of the controlled sequence.

map::const_reference

   typedef A::const_reference const_reference;

The type describes an object that can serve as a constant reference to an element of the controlled sequence.

map::const_reverse_iterator

   typedef reverse_iterator<const_iterator>
       const_reverse_iterator;

The type describes an object that can serve as a constant reverse bidirectional iterator for the controlled sequence.

map::count

   size_type count(const Key& key) const;

The member function returns the number of elements x in the range [lower_bound(key), upper_bound(key)).

map::difference_type

   typedef T3 difference_type;

The signed integer type describes an object that can represent the difference between the addresses of any two elements in the controlled sequence. It is described here as a synonym for the implementation-defined type T3.

map::empty

   bool empty() const;

The member function returns true for an empty controlled sequence.

map::end

   const_iterator end() const;
   iterator end();

The member function returns a bidirectional iterator that points just beyond the end of the sequence.

map::equal_range

   pair<iterator, iterator> equal_range(const Key& key);
   pair<const_iterator, const_iterator>
       equal_range(const Key& key) const;

The member function returns a pair of iterators x such that x.first == lower_bound(key) and x.second == upper_bound(key).

map::erase

   iterator erase(iterator it);
   iterator erase(iterator first, iterator last);
   size_type erase(const Key& key);

The first member function removes the element of the controlled sequence pointed to by it. The second member function removes the elements in the interval [first, last). Both return an iterator that designates the first element remaining beyond any elements removed, or end() if no such element exists.

The third member function removes the elements with sort keys in the range [lower_bound(key), upper_bound(key)). It returns the number of elements it removes.

The member functions never throw an exception.

map::find

   iterator find(const Key& key);
   const_iterator find(const Key& key) const;

The member function returns an iterator that designates the earliest element in the controlled sequence whose sort key has equivalent ordering to key. If no such element exists, the function returns end().

map::get_allocator

   A get_allocator() const;

The member function returns the stored allocator object.

map::insert

   pair<iterator, bool> insert(const value_type& x);
   iterator insert(iterator it, const value_type& x);
   template<class InIt>
       void insert(InIt first, InIt last);

The first member function determines whether an element y exists in the sequence whose key has equivalent ordering to that of x. If not, it creates such an element y and initializes it with x. The function then determines the iterator it that designates y. If an insertion occurred, the function returns pair(it, true). Otherwise, it returns pair(it, false).

The second member function returns insert(x).first, using it as a starting place within the controlled sequence to search for the insertion point. (Insertion can occur in amortized constant time, instead of logarithmic time, if the insertion point immediately precedes it.) The third member function inserts the sequence of element values, for each it in the range [first, last), by calling insert(*it).

If an exception is thrown during the insertion of a single element, the container is left unaltered and the exception is rethrown. If an exception is thrown during the insertion of multiple elements, the container is left in a stable but unspecified state and the exception is rethrown.

map::iterator

   typedef T0 iterator;

The type describes an object that can serve as a bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T0.

map::key_comp

   key_compare key_comp() const;

The member function returns the stored function object that determines the order of elements in the controlled sequence. The stored object defines the member function:

   bool operator()(const Key& x, const Key& y);

which returns true if x strictly precedes y in the sort order.

map::key_compare

   typedef Pred key_compare;

The type describes a function object that can compare two sort keys to determine the relative order of two elements in the controlled sequence.

map::key_type

   typedef Key key_type;

The type describes the sort key object stored in each element of the controlled sequence.

map::lower_bound

   iterator lower_bound(const Key& key);
   const_iterator lower_bound(const Key& key) const;

The member function returns an iterator that designates the earliest element x in the controlled sequence for which key_comp()(x. first, key) is false.

If no such element exists, the function returns end().

map::map

   map();
   explicit map(const Pred& comp);
   map(const Pred& comp, const A& al);
   map(const map& x);
   template<class InIt>
       map(InIt first, InIt last);
   template<class InIt>
       map(InIt first, InIt last,
           const Pred& comp);
   template<class InIt>
       map(InIt first, InIt last,
           const Pred& comp, const A& al);

All constructors store an allocator object and initialize the controlled sequence. The allocator object is the argument al, if present. For the copy constructor, it is x.get_allocator(). Otherwise, it is A().

All constructors also store a function object that can later be returned by calling key_comp(). The function object is the argument comp, if present. For the copy constructor, it is x.key_comp()). Otherwise, it is Pred().

The first three constructors specify an empty initial controlled sequence. The fourth constructor specifies a copy of the sequence controlled by x. The last three constructors specify the sequence of element values [first, last).

map::mapped_type

   typedef T mapped_type;

The type is a synonym for the template parameter T.

map::max_size

   size_type max_size() const;

The member function returns the length of the longest sequence that the object can control.

map::operator[]

   T& operator[](const Key& key);

The member function determines the iterator it as the return value of insert( value_type(key, T()). (It inserts an element with the specified key if no such element exists.) It then returns a reference to (*it).second.

map::pointer

   typedef A::pointer pointer;

The type describes an object that can serve as a pointer to an element of the controlled sequence.

map::rbegin

   const_reverse_iterator rbegin() const;
   reverse_iterator rbegin();

The member function returns a reverse bidirectional iterator that points just beyond the end of the controlled sequence. Hence, it designates the beginning of the reverse sequence.

map::reference

   typedef A::reference reference;

The type describes an object that can serve as a reference to an element of the controlled sequence.

map::rend

   const_reverse_iterator rend() const;
   reverse_iterator rend();

The member function returns a reverse bidirectional iterator that points at the first element of the sequence (or just beyond the end of an empty sequence). Hence, it designates the end of the reverse sequence.

map::reverse_iterator

   typedef reverse_iterator<iterator> reverse_iterator;

The type describes an object that can serve as a reverse bidirectional iterator for the controlled sequence.

map::size

   size_type size() const;

The member function returns the length of the controlled sequence.

map::size_type

   typedef T2 size_type;

The unsigned integer type describes an object that can represent the length of any controlled sequence. It is described here as a synonym for the implementation-defined type T2.

map::swap

   void swap(map& x);

The member function swaps the controlled sequences between *this and x. If get_allocator() == x.get_allocator(), it does so in constant time, it throws an exception only as a result of copying the stored function object of type Pred, and it invalidates no references, pointers, or iterators that designate elements in the two controlled sequences. Otherwise, it performs a number of element assignments and constructor calls proportional to the number of elements in the two controlled sequences.

map::upper_bound

   iterator upper_bound(const Key& key);
   const_iterator upper_bound(const Key& key) const;

The member function returns an iterator that designates the earliest element x in the controlled sequence for which key_comp()(key, x.first) is true.

If no such element exists, the function returns end().

map::value_comp

   value_compare value_comp() const;

The member function returns a function object that determines the order of elements in the controlled sequence.

map::value_compare

   class value_compare
       : public binary_function<value_type, value_type,
           bool> {
   public:
       bool operator()(const value_type& x,
           const value_type& y) const
           {return (comp(x.first, y.first)); }
   protected:
       value_compare(key_compare pr)
           : comp(pr) {}
       key_compare comp;
       };

The type describes a function object that can compare the sort keys in two elements to determine their relative order in the controlled sequence. The function object stores an object comp of type key_compare. The member function operator() uses this object to compare the sort-key components of two element.

map::value_type

   typedef pair<const Key, T> value_type;

The type describes an element of the controlled sequence.

multimap

allocator_type , begin , clear , const_iterator , const_pointer , const_reference , const_reverse_iterator , count , difference_type , empty , end , equal_range , erase , find , get_allocator , insert , iterator , key_comp , key_compare , key_type , lower_bound , mapped_type , max_size , multimap , rbegin , reference , rend , reverse_iterator , size , size_type , swap , upper_bound , value_comp , value_compare , value_type

   template<class Key, class T, class Pred = less<Key>,
       class A = allocator<pair<const Key, T> > >
       class multimap {
   public:
       typedef Key key_type;
       typedef T mapped_type;
       typedef Pred key_compare;
       typedef A allocator_type;
       typedef pair<const Key, T> value_type;
       class value_compare;
       typedef A::reference reference;
       typedef A::const_reference const_reference;
       typedef T0 iterator;
       typedef T1 const_iterator;
       typedef T2 size_type;
       typedef T3 difference_type;
       typedef reverse_iterator<const_iterator>
           const_reverse_iterator;
       typedef reverse_iterator<iterator> reverse_iterator;
       multimap();
       explicit multimap(const Pred& comp);
       multimap(const Pred& comp, const A& al);
       multimap(const multimap& x);
       template<class InIt>
           multimap(InIt first, InIt last);
       template<class InIt>
           multimap(InIt first, InIt last,
               const Pred& comp);
       template<class InIt>
           multimap(InIt first, InIt last,
               const Pred& comp, const A& al);
       iterator begin();
       const_iterator begin() const;
       iterator end();
       const_iterator end() const;
       reverse_iterator rbegin();
       const_reverse_iterator rbegin() const;
       reverse_iterator rend();
       const_reverse_iterator rend() const;
       size_type size() const;
       size_type max_size() const;
       bool empty() const;
       A get_allocator() const;
       iterator insert(const value_type& x);
       iterator insert(iterator it, const value_type& x);
       template<class InIt>
           void insert(InIt first, InIt last);
       iterator erase(iterator it);
       iterator erase(iterator first, iterator last);
       size_type erase(const Key& key);
       void clear();
       void swap(multimap& x);
       key_compare key_comp() const;
       value_compare value_comp() const;
       iterator find(const Key& key);
       const_iterator find(const Key& key) const;
       size_type count(const Key& key) const;
       iterator lower_bound(const Key& key);
       const_iterator lower_bound(const Key& key) const;
       iterator upper_bound(const Key& key);
       const_iterator upper_bound(const Key& key) const;
       pair<iterator, iterator> equal_range(const Key& key);
       pair<const_iterator, const_iterator>
           equal_range(const Key& key) const;
       };

The object orders the sequence it controls by calling a stored function object of type Pred. You access this stored object by calling the member function key_comp(). Such a function object must impose a total ordering on sort keys of type Key. For any element x that precedes y in the sequence, key_comp()(y.first, x.first) is false. (For the default function object less<Key>, sort keys never decrease in value.) Unlike template class map, an object of template class multimap does not ensure that key_comp()(x.first, y.first) is true. (Keys need not be unique.)

multimap::allocator_type

   typedef A allocator_type;

The type is a synonym for the template parameter A.

multimap::begin

   const_iterator begin() const;
   iterator begin();

The member function returns a bidirectional iterator that points at the first element of the sequence (or just beyond the end of an empty sequence).

multimap::clear

   void clear();

The member function calls erase( begin(), end()).

multimap::const_iterator

   typedef T1 const_iterator;

The type describes an object that can serve as a constant bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T1.

multimap::const_pointer

   typedef A::const_pointer const_pointer;

The type describes an object that can serve as a constant pointer to an element of the controlled sequence.

multimap::const_reference

   typedef A::const_reference const_reference;

The type describes an object that can serve as a constant reference to an element of the controlled sequence.

multimap::const_reverse_iterator

   typedef reverse_iterator<const_iterator>
       const_reverse_iterator;

The type describes an object that can serve as a constant reverse bidirectional iterator for the controlled sequence.

multimap::count

   size_type count(const Key& key) const;

The member function returns the number of elements x in the range [lower_bound(key), upper_bound(key)).

multimap::difference_type

   typedef T3 difference_type;

multimap::empty

   bool empty() const;

The member function returns true for an empty controlled sequence.

multimap::end

   const_iterator end() const;
   iterator end();

The member function returns a bidirectional iterator that points just beyond the end of the sequence.

multimap::equal_range

   pair<iterator, iterator> equal_range(const Key& key);
   pair<const_iterator, const_iterator>
       equal_range(const Key& key) const;

The member function returns a pair of iterators x such that x.first == lower_bound(key) and x.second == upper_bound(key).

multimap::erase

   iterator erase(iterator it);
   iterator erase(iterator first, iterator last);
   size_type erase(const Key& key);

The first member function removes the element of the controlled sequence pointed to by it. The second member function removes the elements in the range [first, last). Both return an iterator that designates the first element remaining beyond any elements removed, or end() if no such element exists.

The third member removes the elements with sort keys in the range [lower_bound(key), upper_bound(key)). It returns the number of elements it removes.

The member functions never throw an exception.

multimap::find

   iterator find(const Key& key);
   const_iterator find(const Key& key) const;

multimap::get_allocator

   A get_allocator() const;

The member function returns the stored allocator object.

multimap::insert

   iterator insert(const value_type& x);
   iterator insert(iterator it, const value_type& x);
   template<class InIt>
       void insert(InIt first, InIt last);

The first member function inserts the element x in the controlled sequence, then returns the iterator that designates the inserted element. The second member function returns insert(x), using it as a starting place within the controlled sequence to search for the insertion point. (Insertion can occur in amortized constant time, instead of logarithmic time, if the insertion point immediately precedes it.) The third member function inserts the sequence of element values, for each it in the range [first, last), by calling insert(*it).

multimap::iterator

   typedef T0 iterator;

The type describes an object that can serve as a bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T0.

multimap::key_comp

   key_compare key_comp() const;

The member function returns the stored function object that determines the order of elements in the controlled sequence. The stored object defines the member function:

   bool operator()(const Key& x, const Key& y);

which returns true if x strictly precedes y in the sort order.

multimap::key_compare

   typedef Pred key_compare;

The type describes a function object that can compare two sort keys to determine the relative order of two elements in the controlled sequence.

multimap::key_type

   typedef Key key_type;

The type describes the sort key object stored in each element of the controlled sequence.

multimap::lower_bound

   iterator lower_bound(const Key& key);
   const_iterator lower_bound(const Key& key) const;

The member function returns an iterator that designates the earliest element x in the controlled sequence for which key_comp()(x. first, key) is false.

If no such element exists, the function returns end().

multimap::mapped_type

   typedef T mapped_type;

The type is a synonym for the template parameter T.

multimap::max_size

   size_type max_size() const;

The member function returns the length of the longest sequence that the object can control.

multimap::multimap

   multimap();
   explicit multimap(const Pred& comp);
   multimap(const Pred& comp, const A& al);
   multimap(const multimap& x);
   template<class InIt>
       multimap(InIt first, InIt last);
   template<class InIt>
       multimap(InIt first, InIt last,
           const Pred& comp);
   template<class InIt>
       multimap(InIt first, InIt last,
           const Pred& comp, const A& al);

multimap::pointer

   typedef A::pointer pointer;

The type describes an object that can serve as a pointer to an element of the controlled sequence.

multimap::rbegin

   const_reverse_iterator rbegin() const;
   reverse_iterator rbegin();

The member function returns a reverse bidirectional iterator that points just beyond the end of the controlled sequence. Hence, it designates the beginning of the reverse sequence.

multimap::reference

   typedef A::reference reference;

The type describes an object that can serve as a reference to an element of the controlled sequence.

multimap::rend

   const_reverse_iterator rend() const;
   reverse_iterator rend();

multimap::reverse_iterator

   typedef reverse_iterator<iterator> reverse_iterator;

The type describes an object that can serve as a reverse bidirectional iterator for the controlled sequence.

multimap::size

   size_type size() const;

The member function returns the length of the controlled sequence.

multimap::size_type

   typedef T2 size_type;

The unsigned integer type describes an object that can represent the length of any controlled sequence. It is described here as a synonym for the implementation-defined type T2.

multimap::swap

   void swap(multimap& x);

multimap::upper_bound

   iterator upper_bound(const Key& key);
   const_iterator upper_bound(const Key& key) const;

The member function returns an iterator that designates the earliest element x in the controlled sequence for which key_comp()(key, x.first) is true.

If no such element exists, the function returns end().

multimap::value_comp

   value_compare value_comp() const;

The member function returns a function object that determines the order of elements in the controlled sequence.

multimap::value_compare

   class value_compare
       : public binary_function<value_type, value_type,
           bool> {
   public:
       bool operator()(const value_type& x,
           const value_type& y) const
           {return (comp(x.first, x.second)); }
   protected:
       value_compare(key_compare pr)
           : comp(pr) {}
       key_compare comp;
       };

multimap::value_type

   typedef pair<const Key, T> value_type;

The type describes an element of the controlled sequence.

operator!=

   template<class Key, class T, class Pred, class A>
       bool operator!=(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator!=(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The template function returns !(lhs == rhs).

operator==

   template<class Key, class T, class Pred, class A>
       bool operator==(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator==(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The first template function overloads operator== to compare two objects of template class map. The second template function overloads operator== to compare two objects of template class multimap. Both functions return lhs.size() == rhs.size() && equal(lhs. begin(), lhs. end(), rhs.begin()).

operator<

   template<class Key, class T, class Pred, class A>
       bool operator<(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The first template function overloads operator< to compare two objects of template class map. The second template function overloads operator< to compare two objects of template class multimap. Both functions return lexicographical_compare(lhs. begin(), lhs. end(), rhs.begin(), rhs.end(), lhs.value_comp()).

operator<=

   template<class Key, class T, class Pred, class A>
       bool operator<=(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator<=(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The template function returns !(rhs < lhs).

operator>

   template<class Key, class T, class Pred, class A>
       bool operator>(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator>(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The template function returns rhs < lhs.

operator>=

   template<class Key, class T, class Pred, class A>
       bool operator>=(
           const map <Key, T, Pred, A>& lhs,
           const map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       bool operator!=(
           const multimap <Key, T, Pred, A>& lhs,
           const multimap <Key, T, Pred, A>& rhs);

The template function returns !(lhs < rhs).

swap

   template<class Key, class T, class Pred, class A>
       void swap(
           map <Key, T, Pred, A>& lhs,
           map <Key, T, Pred, A>& rhs);
   template<class Key, class T, class Pred, class A>
       void swap(
           multimap <Key, T, Pred, A>& lhs,
           multimap <Key, T, Pred, A>& rhs);

The template function executes lhs.swap(rhs).

References

algorithm() , functional(C++std) , memory(C++std) , utility(C++std)