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std::multimap<Key,T,Compare,Allocator>::rbegin, std::multimap<Key,T,Compare,Allocator>::crbegin

From cppreference.com
< cpp‎ | container‎ | multimap
 
 
 
 
(1)
reverse_iterator rbegin();
(until C++11)
reverse_iterator rbegin() noexcept;
(since C++11)
(2)
const_reverse_iterator rbegin() const;
(until C++11)
const_reverse_iterator rbegin() const noexcept;
(since C++11)
const_reverse_iterator crbegin() const noexcept;
(3) (since C++11)

Returns a reverse iterator to the first element of the reversed multimap. It corresponds to the last element of the non-reversed multimap. If the multimap is empty, the returned iterator is equal to rend().

range-rbegin-rend.svg

Contents

[edit] Parameters

(none)

[edit] Return value

Reverse iterator to the first element.

[edit] Complexity

Constant.

[edit] Notes

The underlying iterator of the returned reverse iterator is the end iterator. Hence the returned iterator is invalidated if and when the end iterator is invalidated.

libc++ backports crbegin() to C++98 mode.

[edit] Example

#include <algorithm>
#include <iostream>
#include <string>
#include <map>
 
int main()
{
    std::multimap<std::string, int> map
    {
        {"█", 1},
        {"▒", 5},
        {"░", 3},
        {"▓", 7},
        {"▓", 8},
        {"░", 4},
        {"▒", 6},
        {"█", 2}
    };
 
    std::cout << "Print out in reverse order using const reverse iterators:\n";
    std::for_each(map.crbegin(), map.crend(),
        [](std::pair<const std::string, int> const& e)
        {
            std::cout << "{ \"" << e.first << "\", " << e.second << " };\n";
        });
 
    map.rbegin()->second = 42; // OK: non-const value is modifiable
//  map.crbegin()->second = 42; // Error: cannot modify the const value
}

Possible output:

Print out in reverse order using const reverse iterators:
{ "▓", 8 };
{ "▓", 7 };
{ "▒", 6 };
{ "▒", 5 };
{ "░", 4 };
{ "░", 3 };
{ "█", 2 };
{ "█", 1 };

[edit] See also

(C++11)
returns a reverse iterator to the end
(public member function) [edit]
returns a reverse iterator to the beginning of a container or array
(function template) [edit]