////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2001 by Andrei Alexandrescu
// This code accompanies the book:
// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
//     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
// Permission to use, copy, modify, distribute and sell this software for any
//     purpose is hereby granted without fee, provided that the above copyright
//     notice appear in all copies and that both that copyright notice and this
//     permission notice appear in supporting documentation.
// The author or Addison-Wesley Longman make no representations about the
//     suitability of this software for any purpose. It is provided "as is"
//     without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////

// Last update: June 20, 2001

#ifndef __TYPE_INFO_H__
#define __TYPE_INFO_H__

#include <typeinfo>
#include <cassert>
////////////////////////////////////////////////////////////////////////////////
// class TypeInfo
// Purpose: offer a first-class, comparable wrapper over std::type_info
////////////////////////////////////////////////////////////////////////////////

class TypeInfo
{
public:
  // Constructors
  TypeInfo(); // needed for containers
  TypeInfo(const std::type_info&); // non-explicit

  bool operator==(const TypeInfo& typeInfo) const;
  bool operator!=(const TypeInfo& typeInfo) const;
  bool operator<(const TypeInfo& typeInfo) const;
  bool operator>(const TypeInfo& typeInfo) const;
  bool operator<=(const TypeInfo& typeInfo) const;
  bool operator>=(const TypeInfo& typeInfo) const;

  // Access for the wrapped std::type_info
  const std::type_info& get() const;
  // Compatibility functions
  bool before(const TypeInfo& rhs) const;
  const char* name() const;

private:
  const std::type_info* pInfo_;
};

// Implementation

inline TypeInfo::TypeInfo()
{
  class Nil {};
  pInfo_ = &typeid(Nil);
  assert(pInfo_);
}

inline TypeInfo::TypeInfo(const std::type_info& ti)
    : pInfo_(&ti)
{
  assert(pInfo_);
}

inline bool TypeInfo::before(const TypeInfo& rhs) const
{
  assert(pInfo_);
  // type_info::before return type is int in some VC libraries
  return pInfo_->before(*rhs.pInfo_) != 0;
}

inline const std::type_info& TypeInfo::get() const
  {
    assert(pInfo_);
    return *pInfo_;
  }

inline const char* TypeInfo::name() const
{
  assert(pInfo_);
  return pInfo_->name();
}

// Comparison operators

inline bool TypeInfo::operator==(const TypeInfo& rhs) const
// type_info::operator== return type is int in some VC libraries
{ return (this->get() == rhs.get()) != 0; }

inline bool TypeInfo::operator<(const TypeInfo& rhs) const
{ return this->before(rhs); }

inline bool TypeInfo::operator!=(const TypeInfo& rhs) const
{ return !(*this == rhs); }

inline bool TypeInfo::operator>(const TypeInfo& rhs) const
{ return rhs < *this; }

inline bool TypeInfo::operator<=(const TypeInfo& rhs) const
{ return !(*this > rhs); }

inline bool TypeInfo::operator>=(const TypeInfo& rhs) const
{ return !(*this < rhs); }

////////////////////////////////////////////////////////////////////////////////
// Change log:
// June 20, 2001: ported by Nick Thurn to gcc 2.95.3. Kudos, Nick!!!
////////////////////////////////////////////////////////////////////////////////

#endif /* __TYPE_INFO_H__ */