std::span::rend,std::span::crend(3)

NAME
std::span::rend,std::span::crend - std::span::rend,std::span::crend

Synopsis
   constexpr reverse_iterator rend() const noexcept; (1) (since C++20)
   constexpr const_reverse_iterator crend() const noexcept; (2) (since C++23)
   Returns a reverse iterator to the element following the last element of the reversed
   span. It corresponds to the element preceding the first element of the non-reversed
   span. This element acts as a placeholder, attempting to access it results in
   undefined behavior.
   range-rbegin-rend.svg

Parameters
   (none)

Return value
   Reverse iterator to the element following the last element.

Complexity
   Constant.

Example
// Run this code
 #include <algorithm>
 #include <iostream>
 #include <span>
 #include <string_view>
 void ascending(const std::span<const std::string_view> data,
                const std::string_view term)
 {
     std::for_each(data.begin(), data.end(),
         [](const std::string_view x) { std::cout << x << ' '; });
     std::cout << term;
 }
 void descending(const std::span<const std::string_view> data,
                 const std::string_view term)
 {
     std::for_each(data.rbegin(), data.rend(),
         [](const std::string_view x) { std::cout << x << ' '; });
     std::cout << term;
 }
 int main()
 {
     constexpr std::string_view bars[]{"▁","▂","▃","▄","▅","▆","▇","█"};
     ascending(bars, " ");
     descending(bars, "\n");
 }

Output:
 ▁ ▂ ▃ ▄ ▅ ▆ ▇ █ █ ▇ ▆ ▅ ▄ ▃ ▂ ▁

See also
   rbegin returns a reverse iterator to the beginning
   crbegin (public member function)
   (C++23)
   rend returns a reverse end iterator for a container or array
   crend (function template)
   (C++14)