Std::rbegin,std::crbegin (3) Linux Manual Page

std::rbegin,std::crbegin – std::rbegin,std::crbegin

Synopsis

Defined in header<iterator>

    template <class C>
    (since C++ 14)

        auto rbegin(C &c) -> decltype(c.rbegin());
(until C++ 17)

    template <class C>
    (since C++ 17)

        constexpr auto rbegin(C &c) -> decltype(c.rbegin());

template <class C>
(since C++ 14)

    auto rbegin(const C &c) -> decltype(c.rbegin());
(until C++ 17)

    template <class C>
    (since C++ 17)

        constexpr auto rbegin(const C &c) -> decltype(c.rbegin());
(1)

    template <class T, size_t N>
    (since C++ 14)

        reverse_iterator<T *> rbegin(T (&array)[N]);
(1)(until C++ 17)

    template <class T, size_t N>
    (since C++ 17)

        constexpr reverse_iterator<T *> rbegin(T (&array)[N]);
(2)

    template <class C>
    (since C++ 14)

        auto crbegin(const C &c) -> decltype(std::rbegin(c));
(3)(until C++ 17)

    template <class C>
    (since C++ 17)

        constexpr auto crbegin(const C &c) -> decltype(std::rbegin(c));

Returns an iterator to the reverse-beginning of the given container c or array array.
1) Returns a possibly const-qualified iterator to the reverse-beginning of the container c.
2) Returns std::reverse_iterator<T*> to the reverse-beginning of the array array.
3) Returns a const-qualified iterator to the reverse-beginning of the container c.
range-rbegin-rend.svg

Parameters

c – a container with a rbegin method
array – an array of arbitrary type

Return value

An iterator to the reverse-beginning of c or array

Notes

In addition to being included in <iterator>, std::rbegin and std::crbegin are guaranteed to become available if any of the following headers are included: <array>, <deque>, <forward_list>, <list>, <map>, <regex>, <set>
, <span>
(since C++20), <string>
, <string_view>
(since C++17), <unordered_map>, <unordered_set>, and <vector>.
Overloads
Custom overloads of rbegin may be provided for classes that do not expose a suitable rbegin() member function, yet can be iterated. The following overload is already provided by the standard library:
rbegin(std::initializer_list) specializes std::rbegin
(function)
(C++14)

Example

// Run this code

#include <iostream>

#include <vector>

#include <iterator>
int main()

{
    std::vector<int> v = {3, 1, 4};
    auto vi = std::rbegin(v);
    std::cout << *vi << '\n';
    int a[] = {-5, 10, 15};
    auto ai = std::rbegin(a);
    std::cout << *ai << '\n';
}

Output:

4
15

std::rbegin,std::crbegin (3) Linux Manual Page