std::ranges...:operator[](3)

✨ std::ranges::elements_view::iterator::operator[] ✨

okay bestie, welcome to the C++ Standard Libary page for this iterator’s operator[] — yes, that’s the manual name, and yes, we’re keeping the spelling exactly as it appears up top. this is the C++20 era, so hydrate and let’s go 💅

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🎀 NAME 🎀

std::ranges::elements_view::iterator::operator[] — std::ranges::elements_view::iterator::operator[]

periodt, that’s the name and the one-liner both 🫶

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🦋 Synopsis 🦋

the signature, verbatim, because we do not mess with signatures:

constexpr decltype(auto) operator[]( difference_type n ) const

(since C++20)

requires ranges::random_access_range<Base>;

it 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>>>.

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🌸 Parameters 🌸

• n — position relative to current location

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💖 Return value 💖

The element at displacement n relative to the current location. that’s it, that’s the tea ☕

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🍓 Example 🍓

// Run this code

#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
}

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⭐ Output ⭐

2 B β

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👑 See also 👑

• operator* — accesses the N^th tuple element (C++20) (public member function)

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source/version + date, as promised: http://cppreference.com · 2024.06.10 · std::ranges...:operator[](3) — mwah, go slay those tuple elements 💋✨