cuda::experimental::stf::make_tuple_indexwise

Defined in include/cuda/experimental/__stf/utility/core.cuh

template<size_t n, typename F, size_t... i> constexpr auto cuda::experimental::stf::make_tuple_indexwise(F &&f, ::std::index_sequence<i...> = ::std::index_sequence<>())

Creates a std::tuple by applying a callable object f to each integral constant within a given range [0, n).

This function template takes a callable object f and applies it to each integral constant in the range [0, n). The results of the calls are collected into a std::tuple and returned. The callable object is expected to take a single argument of type std::integral_constant<size_t, i>, where i is the current index, and return a value of the desired type and value.

If f returns std::ignore for any argument(s), the corresponding value(s) will be skipped in the resulting tuple.

Example usage:

auto make_double = [](auto index) {
    if constexpr (index == 2)
        return std::ignore;
    else
        return static_cast<double>(index);
};
auto result = make_tuple_indexwise<5>(make_double);
// result is std::tuple<double, double, double, double>{0.0, 1.0, 3.0, 4.0}

Note: Since this function is constexpr, it can be used at compile-time if f is a compile-time invocable object.

Template Parameters

n – The number of times the callable object f should be applied.
F – Type of the callable object.
i... – (Internal) Indices for parameter pack expansion.

Parameters

f – The callable object to apply to each integral constant.

Returns

A std::tuple containing the results of applying f to each integral constant in the range [0, n).