//
//  opaque_typedef.hpp
//  opaque-type
//
//  Created by Sam Jaffe on 8/16/16.
//

#pragma once

#define OPAQUE_TYPE_OPERATOR(name, op) \
  template <typename R, typename O1 = R, typename O2 = R> struct name; \
  \
  template <typename R, typename O1, typename O2> \
  struct name { \
    friend R operator op(O1 const & lhs, O2 const & rhs) { \
      return R(lhs.value() op rhs.value()); \
    } \
  }; \
  \
  template <typename R, typename O2> \
  struct name<R, R, O2> { \
    friend R & operator op##=(R & lhs, O2 const & rhs) { \
      return lhs = R(lhs.value() op rhs.value()); \
    } \
    \
    friend R operator op(R const & lhs, O2 const & rhs) { \
      return R(lhs.value() op rhs.value()); \
    } \
  };

OPAQUE_TYPE_OPERATOR(addition, +)
OPAQUE_TYPE_OPERATOR(subtraction, -)
OPAQUE_TYPE_OPERATOR(multiplication, *)
OPAQUE_TYPE_OPERATOR(division, /)

#undef OPAQUE_TYPE_OPERATOR

template <typename T>
class opaque_typedef {
public:
  opaque_typedef() : _value() {}
  explicit opaque_typedef(T val) : _value(val) {}
  explicit operator T() const { return _value; }
  
  T value() const { return _value; }
private:
  T _value;
};