Namespaces
Variants
Views
Actions

Difference between revisions of "cpp/container/multimap"

From cppreference.com
< cpp‎ | container
m (new member type)
(+extract,merge)
Line 89: Line 89:
 
{{dsc inc | cpp/container/dsc erase | multimap}}
 
{{dsc inc | cpp/container/dsc erase | multimap}}
 
{{dsc inc | cpp/container/dsc swap | multimap}}
 
{{dsc inc | cpp/container/dsc swap | multimap}}
 +
{{dsc inc | cpp/container/dsc extract | multimap}}
 +
{{dsc inc | cpp/container/dsc merge | multimap}}
 +
  
 
{{dsc h2 | Lookup}}
 
{{dsc h2 | Lookup}}

Revision as of 13:21, 19 July 2016

 
 
 
 
Defined in header <map>
(1)
template<

    class Key,
    class T,
    class Compare = std::less<Key>,
    class Allocator = std::allocator<std::pair<const Key, T> >

> class multimap;
(until C++17)
template<

    class Key,
    class T,
    class Compare = std::default_order_t<Key>,
    class Allocator = std::allocator<std::pair<const Key, T> >

> class multimap;
(since C++17)
namespace pmr {

    template <class Key, class T, class Compare = std::default_order_t<Key>>
    using multimap = std::multimap<Key, T, Compare,
                         std::polymorphic_allocator<std::pair<const Key,T>>>

}
(2) (since C++17)

std::multimap is an associative container that contains a sorted list of key-value pairs. Sorting is done according to the comparison function Compare, applied to the keys. Search, insertion, and removal operations have logarithmic complexity.

The order of the key-value pairs whose keys compare equivalent is the order of insertion and does not change. (since C++11)

Everywhere the standard library uses the Template:concept concept, equivalence is determined by using the equivalence relation as described on Template:concept. In imprecise terms, two objects a and b are considered equivalent if neither compares less than the other: !comp(a, b) && !comp(b, a).

std::multimap meets the requirements of Template:concept, Template:concept, Template:concept and Template:concept.

Contents

Member types

Member type Definition
key_type Key[edit]
mapped_type T[edit]
value_type std::pair<const Key, T>[edit]
size_type Unsigned integer type (usually std::size_t)[edit]
difference_type Signed integer type (usually std::ptrdiff_t)[edit]
key_compare Compare[edit]
allocator_type Allocator[edit]
reference value_type&[edit]
const_reference const value_type&[edit]
pointer

Allocator::pointer

(until C++11)

std::allocator_traits<Allocator>::pointer

(since C++11)
[edit]
const_pointer

Allocator::const_pointer

(until C++11)

std::allocator_traits<Allocator>::const_pointer

(since C++11)
[edit]
iterator LegacyBidirectionalIterator to value_type[edit]
const_iterator LegacyBidirectionalIterator to const value_type[edit]
reverse_iterator std::reverse_iterator<iterator>[edit]
const_reverse_iterator std::reverse_iterator<const_iterator>[edit]
node_type (since C++17) a specialization of node handle representing a container node[edit]

Member classes

compares objects of type value_type
(class) [edit]

Member functions

constructs the multimap
(public member function) [edit]
destructs the multimap
(public member function) [edit]
assigns values to the container
(public member function) [edit]
returns the associated allocator
(public member function) [edit]
Iterators
returns an iterator to the beginning
(public member function) [edit]
(C++11)
returns an iterator to the end
(public member function) [edit]
returns a reverse iterator to the beginning
(public member function) [edit]
(C++11)
returns a reverse iterator to the end
(public member function) [edit]
Capacity
checks whether the container is empty
(public member function) [edit]
returns the number of elements
(public member function) [edit]
returns the maximum possible number of elements
(public member function) [edit]
Modifiers
clears the contents
(public member function) [edit]
inserts elements or nodes(since C++17)
(public member function) [edit]
(C++11)
constructs element in-place
(public member function) [edit]
constructs elements in-place using a hint
(public member function) [edit]
erases elements
(public member function) [edit]
swaps the contents
(public member function) [edit]
(C++17)
extracts nodes from the container
(public member function) [edit]
(C++17)
splices nodes from another container
(public member function) [edit]
Lookup
returns the number of elements matching specific key
(public member function) [edit]
finds element with specific key
(public member function) [edit]
returns range of elements matching a specific key
(public member function) [edit]
returns an iterator to the first element not less than the given key
(public member function) [edit]
returns an iterator to the first element greater than the given key
(public member function) [edit]
Observers
returns the function that compares keys
(public member function) [edit]
returns the function that compares keys in objects of type value_type
(public member function) [edit]

Non-member functions

(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(C++20)
lexicographically compares the values of two multimaps
(function template) [edit]
specializes the std::swap algorithm
(function template) [edit]