std::span<T,Extent>::rbegin, std::span<T,Extent>::crbegin

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

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Input/output library

Filesystem library (C++17)

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Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Containers library

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array (C++11)

vector

vector<bool>

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list

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map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

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flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Iterator invalidation

Member function table

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std::span

Member functions

span::span (C++20)

span::operator= (C++20)

Element access

span::front (C++20)

span::back (C++20)

span::operator[] (C++20)

span::data (C++20)

Iterators

span::beginspan::cbegin (C++20)(C++23)

span::endspan::cend (C++20)(C++23)

span::rbeginspan::crbegin (C++20)(C++23)

span::rendspan::crend (C++20)(C++23)

Observers

span::empty (C++20)

span::size (C++20)

span::size_bytes (C++20)

Subviews

span::first (C++20)

span::last (C++20)

span::subspan (C++20)

Non-member functions

as_bytesas_writable_bytes (C++20)(C++20)

Non-member constant

dynamic_extent (C++20)

Deduction guides(C++20)

 

constexpr reverse_iterator rbegin() const noexcept;	(1)	(since C++20)
constexpr const_reverse_iterator crbegin() const noexcept;	(2)	(since C++23)

Returns a reverse iterator to the first element of the reversed span. It corresponds to the last element of the non-reversed span. If the span is empty, the returned iterator is equal to rend().

Parameters

(none)

Return value

Reverse iterator to the first element.

Complexity

Constant.

Example

Run this code

#include <algorithm>
#include <iostream>
#include <iterator>
#include <span>
 
int main()
{
    constexpr std::span<const char> code{ "@droNE_T0P_w$s@s#_SECRET_a,p^42!" };
 
    auto hack = [](const unsigned O) { return O-0141<120; };
 
    std::copy_if(code.rbegin(), code.rend(),
        std::ostream_iterator<const char>(std::cout), hack);
}

Output:

password

See also

rend crend (C++20)(C++23)	returns a reverse iterator to the end (public member function)
rbegincrbegin (C++14)	returns a reverse iterator to the beginning of a container or array (function template)