std::map<Key,T,Compare,Allocator>::rbegin,std::map<Key,T,Compare,Allocator>::crbegin
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reverse_iterator rbegin(); | (1) | (noexcept since C++11) (constexpr since C++26) |
const_reverse_iterator rbegin()const; | (2) | (noexcept since C++11) (constexpr since C++26) |
const_reverse_iterator crbegin()constnoexcept; | (3) | (since C++11) (constexpr since C++26) |
Returns a reverse iterator to the first element of the reversed*this. It corresponds to the last element of the non-reversed*this.
If*this is empty, the returned iterator is equal torend().
Contents |
[edit]Return value
Reverse iterator to the first element.
[edit]Complexity
Constant.
[edit]Notes
Theunderlying iterator of the returned reverse iterator is theend iterator. Hence the returned iterator is invalidated if and when the end iterator is invalidated.
libc++ backportscrbegin() to C++98 mode.
[edit]Example
Run this code
#include <iomanip>#include <iostream>#include <string_view>#include <map> int main(){conststd::map<int,std::string_view> coins{{10,"dime"},{100,"dollar"},{50,"half dollar"},{5,"nickel"},{1,"penny"},{25,"quarter"}};// initializer entries in name alphabetical order std::cout<<"US coins in circulation, largest to smallest denomination:\n";for(auto it= coins.crbegin(); it!= coins.crend();++it)std::cout<<std::setw(11)<< it->second<<" = ¢"<< it->first<<'\n';}
Output:
US coins in circulation, largest to smallest denomination: dollar = ¢100half dollar = ¢50 quarter = ¢25 dime = ¢10 nickel = ¢5 penny = ¢1
[edit]See also
(C++11) | returns a reverse iterator to the end (public member function)[edit] |
(C++14) | returns a reverse iterator to the beginning of a container or array (function template)[edit] |
