cpp-mathematic-limit/include/math/dyn_limit.h

//
//  dyn_limit.h
//  pokemon
//
//  Created by Sam Jaffe on 12/1/23.
//  Copyright © 2023 Sam Jaffe. All rights reserved.
//

#pragma once

#include <math/clamp.h>
#include <math/limit.h>

namespace math {
template <typename T, typename B = T> class DynBound final {
public:
  using value_type = T;
  using underlying_type = value_type const &;
  using bound_type = B;

private:
  bound_type lower_bound_{};
  bound_type upper_bound_{};
  value_type value_{};

public:
  DynBound() = default;
  DynBound(value_type value, bound_type lower_bound, bound_type upper_bound)
      : lower_bound_(lower_bound), upper_bound_(upper_bound),
        value_(clamp(value, lower_bound_, upper_bound_)) {}

  template <bound_type MINIMUM_VALUE, bound_type MAXIMUM_VALUE>
  DynBound(Bound<value_type, MINIMUM_VALUE, MAXIMUM_VALUE> const & other)
      : lower_bound_(MINIMUM_VALUE), upper_bound_(MAXIMUM_VALUE),
        value_(other) {}

  explicit operator value_type const &() const { return value_; }
  value_type const &operator*() const { return value_; }
  value_type const *operator->() const { return &value_; }
  
  auto operator<=>(DynBound const &other) const noexcept = default;

  bool is_min() const { return value_ == lower_bound_; }
  bool is_max() const { return value_ == upper_bound_; }

  DynBound & operator+=(value_type by) {
    using std::min;
    value_ = min(static_cast<value_type>(value_ + by), upper_bound_);
    return *this;
  }

  DynBound & operator-=(value_type by) {
    using std::max;
    value_ = max(static_cast<value_type>(value_ - by), lower_bound_);
    return *this;
  }

  DynBound & operator++() { return operator+=(1); }
  DynBound & operator--() { return operator-=(1); }
  DynBound operator+(value_type by) const { return DynBound{*this} += by; }
  DynBound operator-(value_type by) const { return DynBound{*this} -= by; }

  DynBound operator++(int) {
    DynBound tmp{*this};
    operator++();
    return tmp;
  }

  DynBound operator--(int) {
    DynBound tmp{*this};
    operator--();
    return tmp;
  }
};
}