constexpr decltype(auto) operator[]( difference_type n ) const
requires ranges::random_access_range<Base>;
| (since C++20) |
Returns an element at specified relative location, as if by /*get-element*/(this->base() + n), where for an expression e, /*get-element*/(e) is.
std::get<N>(*e), if ranges::range_reference_t<Base> is a reference type. Otherwise, static_cast<E>(std::get<N>(*e)), where E is std::remove_cv_t<std::tuple_element_t<N, ranges::range_reference_t<Base>>>. | n | - | position relative to current location |
The element at displacement n relative to the current location.
#include <iostream>
#include <ranges>
#include <string_view>
#include <tuple>
int main()
{
using T = std::tuple<int, char, std::string_view>;
const auto il =
{
T{1, 'A', "α"},
T{2, 'B', "β"},
T{3, 'C', "γ"},
};
std::cout << std::views::elements<0>(il)[1] << ' ' // 2
<< std::views::elements<1>(il)[1] << ' ' // B
<< std::views::elements<2>(il)[1] << '\n'; // β
}Output:
2 B β
|
(C++20) | accesses the Nth tuple element (public member function) |
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