std::rbegin, std::crbegin
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Defined in header
<array>
Defined in header
<deque>
Defined in header
<flat_map>
Defined in header
<flat_set>
Defined in header
<forward_list>
Defined in header
<inplace_vector>
Defined in header
<iterator>
Defined in header
<list>
Defined in header
<map>
Defined in header
<regex>
Defined in header
<set>
Defined in header
<span>
Defined in header
<string>
Defined in header
<string_view>
Defined in header
<unordered_map>
Defined in header
<unordered_set>
Defined in header
<vector>
template< class C >
auto rbegin( C& c ) -> decltype(c.rbegin());
(1)
(since C++14) auto rbegin( C& c ) -> decltype(c.rbegin());
(constexpr since C++17)
template< class C >
auto rbegin( const C& c ) -> decltype(c.rbegin());
(2)
(since C++14) auto rbegin( const C& c ) -> decltype(c.rbegin());
(constexpr since C++17)
template< class T, std::size_t N >
std::reverse_iterator <T*> rbegin( T (&array)[N] );
(3)
(since C++14) std::reverse_iterator <T*> rbegin( T (&array)[N] );
(constexpr since C++17)
template< class T >
std::reverse_iterator <const T*> rbegin( std::initializer_list <T> il );
(4)
(since C++14) std::reverse_iterator <const T*> rbegin( std::initializer_list <T> il );
(constexpr since C++17)
template< class C >
auto crbegin( const C& c ) -> decltype(std::rbegin(c));
(5)
(since C++14) auto crbegin( const C& c ) -> decltype(std::rbegin(c));
(constexpr since C++17)
Returns an iterator to the reverse-beginning of the given range.
1,2) Returns c.rbegin(), which is typically an iterator to the reverse-beginning of the sequence represented by c.
5) Returns std::rbegin(c), with c always treated as const-qualified.
[edit] Parameters
c
-
a container or view with a
rbegin member function
array
-
an array of arbitrary type
il
-
an std::initializer_list
[edit] Return value
1,2) c.rbegin()
3) std::reverse_iterator <T*>(array + N)
4) std::reverse_iterator <const T*>(il.end())
5) c.rbegin()
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] Overloads
Custom overloads of rbegin may be provided for classes and enumerations that do not expose a suitable rbegin() member function, yet can be iterated.
Overloads of rbegin found by argument-dependent lookup can be used to customize the behavior of std::ranges::rbegin and std::ranges::crbegin .
[edit] Notes
The overload for std::initializer_list is necessary because it does not have a member function rbegin.
[edit] Example
Run this code
#include <iostream> #include <iterator> #include <vector> int main() { std::vector <int> v = {3, 1, 4}; auto vi = std::rbegin(v); // the type of "vi" is std::vector<int>::reverse_iterator std::cout << "*vi = " << *vi << '\n'; *std::rbegin(v) = 42; // OK: after assignment v[2] == 42 // *std::crbegin(v) = 13; // error: the location is read-only int a[] = {-5, 10, 15}; auto ai = std::rbegin(a); // the type of "ai" is std::reverse_iterator<int*> std::cout << "*ai = " << *ai << '\n'; auto il = {3, 1, 4}; // the type of "it" below is std::reverse_iterator<int const*>: for (auto it = std::rbegin(il); it != std::rend (il); ++it) std::cout << *it << ' '; std::cout << '\n'; }
Output:
*vi = 4 *ai = 15 4 1 3
[edit] See also
(C++11)(C++14)
(function template) [edit]