std::ranges::forward_range

Определён в заголовке `<ranges>`
template< class T > concept forward_range = ranges::input_range<T> && std::forward_iterator<ranges::iterator_t<T>>;		(начиная с C++20)

Концепция forward_range является уточнением range, для которой ranges::begin возвращает модель forward_iterator.

Пример

#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() {}

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/cpp/ranges/forward_range