cpp-descriptive-pointers/include/pointers/ptr_compare.hpp

//
//  ptr_compare.hpp
//  pointers
//
//  Created by Sam Jaffe on 1/5/17.
//

#pragma once

#define POINTER_TEMPLATE_COMPARE(ptr_t)                                        \
  POINTER_TEMPLATE_COMPARE_FULL(ptr_t, (typename T), (T), (typename U), (U))

#define EXPAND(...) __VA_ARGS__

#define POINTER_TEMPLATE_COMPARE_FULL(ptr_t, T_tname, T, U_tname, U)           \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator==(ptr_t<EXPAND T> const & lhs,                                 \
                  ptr_t<EXPAND U> const & rhs) noexcept {                      \
    return lhs.get() == rhs.get();                                             \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator!=(ptr_t<EXPAND T> const & lhs,                                 \
                  ptr_t<EXPAND U> const & rhs) noexcept {                      \
    return !(lhs == rhs);                                                      \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator<(ptr_t<EXPAND T> const & lhs,                                  \
                 ptr_t<EXPAND U> const & rhs) noexcept {                       \
    typedef                                                                    \
        typename std::common_type<typename ptr_t<EXPAND T>::pointer,           \
                                  typename ptr_t<EXPAND U>::pointer>::type V;  \
    return std::less<V>(lhs.get(), rhs.get());                                 \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator>(ptr_t<EXPAND T> const & lhs,                                  \
                 ptr_t<EXPAND U> const & rhs) noexcept {                       \
    return rhs < lhs;                                                          \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator<=(ptr_t<EXPAND T> const & lhs,                                 \
                  ptr_t<EXPAND U> const & rhs) noexcept {                      \
    return !(rhs < lhs);                                                       \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname, EXPAND U_tname>                                    \
  bool operator>=(ptr_t<EXPAND T> const & lhs,                                 \
                  ptr_t<EXPAND U> const & rhs) noexcept {                      \
    return !(lhs < rhs);                                                       \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator==(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {      \
    return !lhs;                                                               \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator==(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {      \
    return !rhs;                                                               \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator!=(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {      \
    return static_cast<bool>(lhs);                                             \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator!=(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {      \
    return static_cast<bool>(rhs);                                             \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator<(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {       \
    typedef typename ptr_t<EXPAND T>::pointer V;                               \
    return std::less<V>(lhs.get(), nullptr);                                   \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator<(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {       \
    typedef typename ptr_t<EXPAND T>::pointer V;                               \
    return std::less<V>(nullptr, rhs.get());                                   \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator>(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {       \
    return nullptr < lhs;                                                      \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator>(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {       \
    return rhs < nullptr;                                                      \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator<=(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {      \
    return !(nullptr < lhs);                                                   \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator<=(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {      \
    return !(rhs < nullptr);                                                   \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator>=(ptr_t<EXPAND T> const & lhs, std::nullptr_t) noexcept {      \
    return !(lhs < nullptr);                                                   \
  }                                                                            \
                                                                               \
  template <EXPAND T_tname>                                                    \
  bool operator>=(std::nullptr_t, ptr_t<EXPAND T> const & rhs) noexcept {      \
    return !(nullptr < rhs);                                                   \
  }