std::ranges::forward_range
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
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Ranges library
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Defined in header
<ranges>
template< class T >
(since C++20)
concept forward_range =
The forward_range concept is a refinement of range for which ranges::begin returns a model of forward_iterator.
[edit] Example
Run this code
#include <forward_list> #include <queue> #include <ranges> #include <span> #include <stack> #include <tuple> const char* str{"not a forward range"}; const char str2[] = "a forward range"; static_assert( std::ranges::forward_range<decltype("a forward range")> && !std::ranges::forward_range<decltype(str)> && std::ranges::forward_range<decltype(str2)> && !std::ranges::forward_range<std::stack <char>> && std::ranges::forward_range<std::forward_list <char>> && !std::ranges::forward_range<std::tuple <std::forward_list <char>>> && std::ranges::forward_range<std::span <char>> && !std::ranges::forward_range<std::queue <char>> && ""); int main() {}