my worst template code is this recursive struct
template<class Truth, class T, typename... Args>
struct conditional_impl {
using type = typename std::enable_if_t<(sizeof...(Args) == 0 && std::is_same_v<Truth, qpl::default_type>) || qpl::is_truth_type<Truth>(),
std::conditional_t<(sizeof...(Args) >= 2), std::conditional_t<qpl::is_true<Truth>(), std::conditional_t<std::is_same_v<T, qpl::error_type>, T, qpl::identity<T>>, qpl::conditional_indirection<Args...>>,
std::conditional_t<(sizeof...(Args) == 0), std::conditional_t<std::is_same_v<Truth, qpl::default_type>, std::conditional_t<std::is_same_v<T, qpl::error_type>, T, qpl::identity<T>>, std::enable_if<qpl::is_true<Truth>(), T>>,
std::conditional_t<qpl::is_true<Truth>(), std::conditional_t<std::is_same_v<T, qpl::error_type>, T, qpl::identity<T>>, qpl::empty_indirection<Args...>>>>>::type;
};
it basically unrolls nested std::conditional_t's
so instead of writing
template<std::size_t N>
using unsigned_type = typename
std::conditional_t < N == std::size_t{ 8 }, std::type_identity<std::uint8_t>,
std::conditional_t < N == std::size_t{ 16 }, std::type_identity<std::uint16_t>,
std::conditional_t < N == std::size_t{ 32 }, std::type_identity<std::uint32_t>,
std::enable_if < N == std::size_t{ 64 }, std::uint64_t>>>>::type;
I can write
template<typename T>
using unsigned_type = qpl::conditional<
qpl::if_true<qpl::is_arithmetic<std::decay_t<T>>()>,
qpl::conditional<
qpl::if_true<qpl::bits_in_type<T>() == std::size_t{ 8 }>, qpl::u8,
qpl::if_true<qpl::bits_in_type<T>() == std::size_t{ 16 }>, qpl::u16,
qpl::if_true<qpl::bits_in_type<T>() == std::size_t{ 32 }>, qpl::u32,
qpl::if_true<qpl::bits_in_type<T>() == std::size_t{ 64 }>, qpl::u64,
qpl::default_error>,
qpl::default_error>;
(not the lack of >>>> closing templates)
xD
1
. Contribute to nektos/act development by creating an account on GitHub.
3
1
