std::ranges::transform, std::ranges::unary_transform_result, std::ranges::binary_transform_result

struct transform_fn
{
    // 最初のバージョン
    template<std::input_iterator I, std::sentinel_for<I> S, std::weakly_incrementable O,
             std::copy_constructible

（注：指定された条件により、HTMLタグ・属性は翻訳せず、C++固有用語も翻訳していません。テキスト部分が既に英語の専門用語のみであるため、翻訳対象となる自然言語テキストが存在しません） F, class Proj = std::identity>
    requires std::indirectly_writable<O, std::indirect_result_t<F&,
                                                                std::projected<I, Proj>>>
    constexpr ranges::unary_transform_result<I, O>
        operator()(I first1, S last1, O result, F op, Proj proj = {}) const
    {
        for (; first1 != last1; ++first1, (void)++result)
            *result = std::invoke(op, std::invoke(proj, *first1));
        return {std::move(first1), std::move(result)};
    }
    // 第二バージョン
    template<ranges::input_range R, std::weakly_incrementable O,
             std::copy_constructible

（注：元のテキストはC++の概念名「std::copy_constructible」であり、HTMLタグとC++固有の用語は翻訳対象外のため、出力は入力と同一となります） F, class Proj = std::identity>
    requires std::indirectly_writable<O,
                 std::indirect_result_t<F&, std::projected<ranges::iterator_t<R>, Proj>>>
    constexpr ranges::unary_transform_result<ranges::borrowed_iterator_t<R>, O>
        operator()(R&& r, O result, F op, Proj proj = {}) const
    {
        return (*this)(ranges::begin(r), ranges::end(r), std::move(result),
                       std::move(op), std::move(proj));
    }
    // 第三バージョン
    template<std::input_iterator I1, std::sentinel_for<I1> S1,
             std::input_iterator I2, std::sentinel_for<I2> S2,
             std::weakly_incrementable O,
             std::copy_constructible F,
             class Proj1 = std::identity, class Proj2 = std::identity>
    requires std::indirectly_writable<O,
                 std::indirect_result_t<F&,
                                        std::projected<I1, Proj1>,
                                        std::projected<I2, Proj2>>>
    constexpr ranges::binary_transform_result<I1, I2, O>
        operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result,
                   F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {}) const
    {
        for (; first1 != last1 && first2 != last2;
             ++first1, (void)++first2, (void)++result)
            *result = std::invoke(binary_op,
                                  std::invoke(proj1, *first1),
                                  std::invoke(proj2, *first2));
        return {std::move(first1), std::move(first2), std::move(result)};
    }
    // 第四バージョン
    template<ranges::input_range R1, ranges::input_range R2,
             std::weakly_incrementable O, std::copy_constructible F,
             class Proj1 = std::identity, class Proj2 = std::identity>
    requires std::indirectly_writable<O,
                 std::indirect_result_t<F&,
                     std::projected<ranges::iterator_t<R1>, Proj1>,
                     std::projected<ranges::iterator_t<R2>, Proj2>>>
    constexpr ranges::binary_transform_result<ranges::borrowed_iterator_t<R1>,
                                              ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result,
                   F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {}) const
    {
        return (*this)(ranges::begin(r1), ranges::end(r1),
                       ranges::begin(r2), ranges::end(r2),
                       std::move(result), std::move(binary_op),
                       std::move(proj1), std::move(proj2));
    }
};
inline constexpr transform_fn transform;