Kokkos_Pair.hpp

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#ifndef KOKKOS_PAIR_HPP
#define KOKKOS_PAIR_HPP
 
#include <Kokkos_Macros.hpp>
#include <utility>
 
namespace Kokkos {
template <class T1, class T2>
struct pair {
  using first_type = T1;
  using second_type = T2;
 
  first_type first;
  second_type second;
 
  KOKKOS_DEFAULTED_FUNCTION constexpr pair() = default;
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(first_type const& f,
                                             second_type const& s)
      : first(f), second(s) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const pair<U, V>& p)
      : first(p.first), second(p.second) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const volatile pair<U, V>& p)
      : first(p.first), second(p.second) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION pair<T1, T2>& operator=(const pair<U, V>& p) {
    first  = p.first;
    second = p.second;
    return *this;
  }
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION void operator=(
      const volatile pair<U, V>& p) volatile {
    first  = p.first;
    second = p.second;
    // We deliberately do not return anything here.  See explanation
    // in public documentation above.
  }
 
  // from std::pair<U,V>
  template <class U, class V>
  pair(const std::pair<U, V>& p) : first(p.first), second(p.second) {}
 
  std::pair<T1, T2> to_std_pair() const {
    return std::make_pair(first, second);
  }
};
 
template <class T1, class T2>
struct pair<T1&, T2&> {
  using first_type = T1&;
  using second_type = T2&;
 
  first_type first;
  second_type second;
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(first_type f, second_type s)
      : first(f), second(s) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const pair<U, V>& p)
      : first(p.first), second(p.second) {}
 
  // from std::pair<U,V>
  template <class U, class V>
  pair(const std::pair<U, V>& p) : first(p.first), second(p.second) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION pair<first_type, second_type>& operator=(
      const pair<U, V>& p) {
    first  = p.first;
    second = p.second;
    return *this;
  }
 
  std::pair<T1, T2> to_std_pair() const {
    return std::make_pair(first, second);
  }
};
 
template <class T1, class T2>
struct pair<T1, T2&> {
  using first_type = T1;
  using second_type = T2&;
 
  first_type first;
  second_type second;
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(first_type const& f, second_type s)
      : first(f), second(s) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const pair<U, V>& p)
      : first(p.first), second(p.second) {}
 
  // from std::pair<U,V>
  template <class U, class V>
  pair(const std::pair<U, V>& p) : first(p.first), second(p.second) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION pair<first_type, second_type>& operator=(
      const pair<U, V>& p) {
    first  = p.first;
    second = p.second;
    return *this;
  }
 
  std::pair<T1, T2> to_std_pair() const {
    return std::make_pair(first, second);
  }
};
 
template <class T1, class T2>
struct pair<T1&, T2> {
  using first_type = T1&;
  using second_type = T2;
 
  first_type first;
  second_type second;
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(first_type f, second_type const& s)
      : first(f), second(s) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const pair<U, V>& p)
      : first(p.first), second(p.second) {}
 
  // from std::pair<U,V>
  template <class U, class V>
  pair(const std::pair<U, V>& p) : first(p.first), second(p.second) {}
 
  template <class U, class V>
  KOKKOS_FORCEINLINE_FUNCTION pair<first_type, second_type>& operator=(
      const pair<U, V>& p) {
    first  = p.first;
    second = p.second;
    return *this;
  }
 
  std::pair<T1, T2> to_std_pair() const {
    return std::make_pair(first, second);
  }
};
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION bool operator==(const pair<T1, T2>& lhs,
                                            const pair<T1, T2>& rhs) {
  return lhs.first == rhs.first && lhs.second == rhs.second;
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator!=(const pair<T1, T2>& lhs,
                                                      const pair<T1, T2>& rhs) {
  return !(lhs == rhs);
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator<(const pair<T1, T2>& lhs,
                                                     const pair<T1, T2>& rhs) {
  return lhs.first < rhs.first ||
         (!(rhs.first < lhs.first) && lhs.second < rhs.second);
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator<=(const pair<T1, T2>& lhs,
                                                      const pair<T1, T2>& rhs) {
  return !(rhs < lhs);
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator>(const pair<T1, T2>& lhs,
                                                     const pair<T1, T2>& rhs) {
  return rhs < lhs;
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator>=(const pair<T1, T2>& lhs,
                                                      const pair<T1, T2>& rhs) {
  return !(lhs < rhs);
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION constexpr pair<T1, T2> make_pair(T1 x, T2 y) {
  return (pair<T1, T2>(x, y));
}
 
template <class T1, class T2>
KOKKOS_FORCEINLINE_FUNCTION pair<T1&, T2&> tie(T1& x, T2& y) {
  return (pair<T1&, T2&>(x, y));
}
 
//
// Specialization of Kokkos::pair for a \c void second argument.  This
// is not actually a "pair"; it only contains one element, the first.
//
template <class T1>
struct pair<T1, void> {
  using first_type  = T1;
  using second_type = void;
 
  first_type first;
  enum { second = 0 };
 
  KOKKOS_DEFAULTED_FUNCTION constexpr pair() = default;
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const first_type& f) : first(f) {}
 
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const first_type& f, int)
      : first(f) {}
 
  template <class U>
  KOKKOS_FORCEINLINE_FUNCTION constexpr pair(const pair<U, void>& p)
      : first(p.first) {}
 
  template <class U>
  KOKKOS_FORCEINLINE_FUNCTION pair<T1, void>& operator=(
      const pair<U, void>& p) {
    first = p.first;
    return *this;
  }
};
 
//
// Specialization of relational operators for Kokkos::pair<T1,void>.
//
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator==(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return lhs.first == rhs.first;
}
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator!=(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return !(lhs == rhs);
}
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator<(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return lhs.first < rhs.first;
}
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator<=(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return !(rhs < lhs);
}
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator>(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return rhs < lhs;
}
 
template <class T1>
KOKKOS_FORCEINLINE_FUNCTION constexpr bool operator>=(
    const pair<T1, void>& lhs, const pair<T1, void>& rhs) {
  return !(lhs < rhs);
}
 
namespace Impl {
 
template <class T>
struct is_pair_like : std::false_type {};
template <class T, class U>
struct is_pair_like<Kokkos::pair<T, U>> : std::true_type {};
template <class T, class U>
struct is_pair_like<std::pair<T, U>> : std::true_type {};
 
}  // end namespace Impl
 
}  // namespace Kokkos
 
#endif  // KOKKOS_PAIR_HPP