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d1be154 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | // 2020/08/28 - Created by netcan: https://github.com/netcan
#pragma once
#include <cstddef>
#include <tuple>
namespace tf {
namespace dsl {
namespace detail {
// get tuple element index by f, if not exists then index >= tuple_size
template <typename TUP, template <typename> class F, typename = void>
struct TupleElementByF {
constexpr static size_t Index = 0;
};
template <template <typename> class F, typename H, typename... Ts>
struct TupleElementByF<std::tuple<H, Ts...>, F, std::enable_if_t<F<H>::value>> {
constexpr static size_t Index = 0;
};
template <template <typename> class F, typename H, typename... Ts>
struct TupleElementByF<std::tuple<H, Ts...>, F,
std::enable_if_t<!F<H>::value>> {
constexpr static size_t Index =
1 + TupleElementByF<std::tuple<Ts...>, F>::Index;
};
template <typename T, typename TUP, size_t... Is>
constexpr inline T AggregationByTupImpl(TUP &&tup, std::index_sequence<Is...>) {
return T{std::get<Is>(tup)...};
}
} // namespace detail
template <typename TUP, template <typename> class F>
constexpr size_t TupleElementByF_v = detail::TupleElementByF<TUP, F>::Index;
template <typename T, typename TUP>
constexpr inline T AggregationByTup(TUP &&tup) {
return detail::AggregationByTupImpl<T>(
std::forward<TUP>(tup),
std::make_index_sequence<std::tuple_size<std::decay_t<TUP>>::size>{});
}
} // namespace dsl
} // namespace tf
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