std::map<Key,T,Compare,Allocator>::rbegin, std::map<Key,T,Compare,Allocator>::crbegin
From cppreference.com
reverse_iterator rbegin();
|
(1) | (noexcept since C++11) |
const_reverse_iterator rbegin() const;
|
(2) | (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 map. It corresponds to the last element of the non-reversed map. If the map is empty, the returned iterator is equal to rend().
Return value
Reverse iterator to the first element.
Complexity
Constant.
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.
Example
Run this code
#include <iomanip>
#include <iostream>
#include <string_view>
#include <map>
int main()
{
const std::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 = ¢100
half dollar = ¢50
quarter = ¢25
dime = ¢10
nickel = ¢5
penny = ¢1