other/min_assign_action.cpp

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• Last update: 2020-02-14 16:53:57+09:00

Depends on

• other/min_semigroup.cpp
• other/right_zero_semigroup.cpp
• other/semigroup_to_monoid.cpp

Code

#include "other/min_semigroup.cpp"
#include "other/right_zero_semigroup.cpp"
#include "other/semigroup_to_monoid.cpp"

#include <optional>

template <class W> class min_assign_action {
  using T = typename W::value_type;
  using U = std::optional<T>;

public:
  using value_structure = semigroup_to_monoid<min_semigroup<W>>;
  using operator_structure = semigroup_to_monoid<right_zero_semigroup<T>>;
  static constexpr U operation(const U &l, const U &r) noexcept {
    return r ? r : l;
  }
};

#line 1 "other/min_semigroup.cpp"
template <class W> class min_semigroup {
  using T = typename W::value_type;

public:
  using value_type = T;
  static constexpr T operation(const T &l, const T &r) noexcept {
    return W::compare(l, r) ? l : r;
  }
};
#line 1 "other/right_zero_semigroup.cpp"
template <class T> class right_zero_semigroup {
public:
  using value_type = T;
  static constexpr T operation(const T &, const T &r) noexcept { return r; }
};
#line 1 "other/semigroup_to_monoid.cpp"
#include <optional>
#include <utility>

template <class S> class semigroup_to_monoid {
  using T = std::optional<typename S::value_type>;

public:
  using value_type = T;
  static constexpr T operation(const T &l, const T &r) noexcept {
    if (!l)
      return r;
    if (!r)
      return l;
    return T(std::in_place, S::operation(*l, *r));
  }
  static constexpr T identity{std::nullopt};
};
#line 4 "other/min_assign_action.cpp"

#line 6 "other/min_assign_action.cpp"

template <class W> class min_assign_action {
  using T = typename W::value_type;
  using U = std::optional<T>;

public:
  using value_structure = semigroup_to_monoid<min_semigroup<W>>;
  using operator_structure = semigroup_to_monoid<right_zero_semigroup<T>>;
  static constexpr U operation(const U &l, const U &r) noexcept {
    return r ? r : l;
  }
};

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