[C++26] std::execution

Reference:
https://en.cppreference.com/w/cpp/experimen

P3288R3 std::elide
https://www.virjacode.com/papers/p3288.htm

code:

constexpr explicit operation_state(Range&& r, Receiver rcvr)
    : /* ... */
    states_(
        std::from_range,
        std::ranges::views::transform(
            std::forward<Range>(r),
            [&]<typename U> requires
                std::constructible_from<ender, U>(U&& u)
            {
                return elide([&, s = std::forward<U>(u)]() mutable {
                    return state_(*this, std::move(s));
                });
            })),
    /* ... */
{}