◐ Shell
clean mode source ↗

std::ranges::slide_view<V>::begin - cppreference.com

From cppreference.com

constexpr auto begin()
    requires (!(/*simple-view*/<V> && /*slide-caches-nothing*/<const V>));
(1) (since C++23) 
constexpr auto begin() const
    requires /*slide-caches-nothing*/<const V>;
(2) (since C++23)

Returns an iterator to the first element of the slide_view.

return iterator<false>(ranges::begin(base_),
                       ranges::next(ranges::begin(base_), n_ - 1, ranges::end(base_)),
                       n_);

Otherwise, equivalent to return iterator<false>(ranges::begin(base_), n_);.

If V models slide-caches-first this function caches the result within the cached_begin_ for use on subsequent calls. This is necessary to provide the amortized constant-time complexity required by the

range

.

2) Equivalent to return iterator<true>(ranges::begin(base_), n_);.

Parameters

(none)

Return value

An iterator to the first element of slide_view, which points to the n_-sized subrange of the underlying view type: V for overload (1) or const V for overload (2).

Example

#include <iostream>
#include <ranges>
#include <string_view>
using namespace std::literals;

int main()
{
    static constexpr auto source = {"∀x"sv, "∃y"sv, "ε"sv, "δ"sv};
    auto view{std::ranges::slide_view(source, 2)};
    const auto subrange{*(view.begin())};
    for (std::string_view const s : subrange)
        std::cout << s << ' ';
    std::cout << '\n';
}

Output:

See also