transform_maybe_view

Takes a function from range_reference_t<Range> to optional<U>. Transforms the given range by calling the function on each element, but only returning the value of engaged optionals.

std::vector<int> vec{ 0,1,2,3,4 };
auto f = [](auto i) { return (i % 2 == 0) ? std::optional(i / 2) : std::nullopt; };

for (auto&& e : vec | tl::views::transform_maybe(f)) {
   std::cout << e << ' ';
   //0 1 2
}

template <class V, class F> class tl::transform_maybe_view

Requires: input_range<V> && view<V> && std::invocable<F, range_reference_t<V>>

Reference: range_reference_t<V>::value_type&

Category: At most bidirectional.

Sized: Never.

Common: When V is common.

Const-iterable: Never.

Borrowed: Never.

transform_maybe_view(V range, F func)

constexpr inline auto tl::views::transform_maybe

template<class V, class F>
constexpr auto operator()(V &&range, F f) const

Constructs a tl::transform_maybe_view<std::views::all_t<V>, F>.

template<class V, class F>
constexpr auto operator()(F f) const

Partial application for piping, e.g. ranges | tl::views::transform_maybe(func).