traits/Tuple.cpp

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Last update: 2023-02-27 10:03:35-03:00

Depends on

bits/stdc++.h

Required by

pbds/TreeUpdater.cpp

Code

#ifndef _LIB_TRAITS_TUPLE
#define _LIB_TRAITS_TUPLE
#include <bits/stdc++.h>

namespace lib {
using namespace std;
namespace traits {
template <class Tuple, class T, std::size_t Index = 0> struct find_first;

template <std::size_t Index, bool Valid>
struct find_first_final_test
    : public std::integral_constant<std::size_t, Index> {};

template <std::size_t Index> struct find_first_final_test<Index, false> {
  static_assert(Index == -1, "Type not found in find_first");
};

template <class Head, class T, std::size_t Index>
struct find_first<std::tuple<Head>, T, Index>
    : public find_first_final_test<Index, std::is_same<Head, T>::value> {};

template <class Head, class... Rest, class T, std::size_t Index>
struct find_first<std::tuple<Head, Rest...>, T, Index>
    : public std::conditional<
          std::is_same<Head, T>::value,
          std::integral_constant<std::size_t, Index>,
          find_first<std::tuple<Rest...>, T, Index + 1>>::type {};
} // namespace traits
} // namespace lib

#endif

#line 1 "traits/Tuple.cpp"


#include <bits/stdc++.h>

namespace lib {
using namespace std;
namespace traits {
template <class Tuple, class T, std::size_t Index = 0> struct find_first;

template <std::size_t Index, bool Valid>
struct find_first_final_test
    : public std::integral_constant<std::size_t, Index> {};

template <std::size_t Index> struct find_first_final_test<Index, false> {
  static_assert(Index == -1, "Type not found in find_first");
};

template <class Head, class T, std::size_t Index>
struct find_first<std::tuple<Head>, T, Index>
    : public find_first_final_test<Index, std::is_same<Head, T>::value> {};

template <class Head, class... Rest, class T, std::size_t Index>
struct find_first<std::tuple<Head, Rest...>, T, Index>
    : public std::conditional<
          std::is_same<Head, T>::value,
          std::integral_constant<std::size_t, Index>,
          find_first<std::tuple<Rest...>, T, Index + 1>>::type {};
} // namespace traits
} // namespace lib