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std::ranges::adjacent_view<V,N>::iterator<Const>::operator[]

constexpr auto operator[]( difference_type n ) const
    requires ranges::random_access_range<Base>;
 (since C++23)

Returns an element at specified relative location.

Let current_ be an underlying array of iterators.

Equivalent to:

return __tuple_transform([&](auto& i) -> decltype(auto) { return i[n]; }, current_);

Parameters

n - position relative to current location

Return value

the element at displacement n relative to the current location.

Example

A link to test: Compiler Explorer/g++-13.

#include <ranges>
#include <tuple>
 
int main()
{
    constexpr static auto v = {0, 1, 2, 3, 4, 5};
    //                               └──┬──┘  
    //                                  └─────────────────┐
    constexpr auto view = v | std::views::adjacent<3>; // │
    //                 ┌───────────────────┬──────────────┘ 
    //                 │                ┌──┴──┐
    static_assert(view[2] == std::tuple{2, 3, 4});
}

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