std::map<Key,T,Compare,Allocator>::rend, std::map<Key,T,Compare,Allocator>::crend
From cppreference.com
(1) | ||
reverse_iterator rend(); |
(until C++11) | |
reverse_iterator rend() noexcept; |
(since C++11) | |
(2) | ||
const_reverse_iterator rend() const; |
(until C++11) | |
const_reverse_iterator rend() const noexcept; |
(since C++11) | |
const_reverse_iterator crend() const noexcept; |
(3) | (since C++11) |
Returns a reverse iterator to the element following the last element of the reversed map
. It corresponds to the element preceding the first element of the non-reversed map
. This element acts as a placeholder, attempting to access it results in undefined behavior.
Contents |
[edit] Parameters
(none)
[edit] Return value
Reverse iterator to the element following the last element.
[edit] Complexity
Constant.
[edit] Example
Run this code
#include <chrono> #include <iomanip> #include <iostream> #include <map> #include <string_view> using namespace std::chrono; // until C++20 chrono operator<< ready std::ostream& operator<<(std::ostream& os, const year_month_day& ymd) { return os << std::setfill('0') << static_cast<int>(ymd.year()) << '/' << std::setw(2) << static_cast<unsigned>(ymd.month()) << '/' << std::setw(2) << static_cast<unsigned>(ymd.day()); } int main() { const std::map<year_month_day, int> messages { {February/17/2023, 10}, {February/17/2023, 20}, {February/16/2022, 30}, {October/22/2022, 40}, {June/14/2022, 50}, {November/23/2021, 60}, {December/10/2022, 55}, {December/12/2021, 45}, {April/1/2020, 42}, {April/1/2020, 24} }; std::cout << "Messages received, reverse date order:\n"; for (auto it = messages.crbegin(); it != messages.crend(); ++it) std::cout << it->first << " : " << it->second << '\n'; }
Possible output:
Messages received, reverse date order: 2023/02/17 : 10 2022/12/10 : 55 2022/10/22 : 40 2022/06/14 : 50 2022/02/16 : 30 2021/12/12 : 45 2021/11/23 : 60 2020/04/01 : 42
[edit] See also
(C++11) |
returns a reverse iterator to the beginning (public member function) |
(C++14) |
returns a reverse end iterator for a container or array (function template) |