tuple_transform.h

#pragma once
 
#include <tuple>
 
namespace TuringSim::Utils {
    namespace {
        template<size_t N, typename Src, typename Destination, typename Func>
        [[maybe_unused]]constexpr void tuple_call_assign(Src const& source, Destination& destination, Func f) {
            std::get<N>(destination) = f(std::get<N>(source));
        }
 
        template<typename Src, typename Destination, typename Func, size_t... Is>
        [[maybe_unused]]constexpr void tuple_transform_index(Src const& source, Destination& destination, Func f, std::index_sequence<Is...>) {
            using expander = int[]; /* Useful to ensure sequence point in evaluation of the expansion below */
            (void) expander{0, (tuple_call_assign<Is>(source, destination, f), 0)...};
        }
    }
 
    template<typename... Src, typename... Destination, typename Func>
    constexpr void tuple_transform(std::tuple<Destination...>& destination, Func f, std::tuple<Src...> const& source) {
        static_assert(sizeof...(Src) == sizeof...(Destination), "Tuples must have the same length");
        tuple_transform_index<>(source, destination, f, std::index_sequence_for<Src...>());
    }
}