gtkradiant/tools/urt/libs/generic/reference.h

#if !defined(INCLUDED_GENERIC_REFERENCE_H)
#define INCLUDED_GENERIC_REFERENCE_H

/// \file
/// \brief Wrappers to allow storing objects in templated containers using 'reference' semantics. 

/// \brief A reference to a mutable object.
/// Has 'reference' semantics, except for \c 'operator==' and \c 'operator.'.
/// \param Type The type of the referenced object.
template<typename Type>
class Reference
{ 
  Type* m_contained;
public:
  explicit Reference(Type& contained) : m_contained(&contained)
  {
  }
  Type& operator*() const
  {
    return *m_contained;
  }
  Type* operator->() const
  {
    return m_contained;
  }
  operator Type&() const
  {
    return *m_contained;
  }
  Type& get() const
  {
    return *m_contained;
  }
  Type* get_pointer() const
  {
    return m_contained;
  }
};

template<typename Type>
bool operator<(const Reference<Type>& self, const Reference<Type>& other)
{
  return self.get() < other.get();
}
template<typename Type>
bool operator==(const Reference<Type>& self, const Reference<Type>& other)
{
  return self.get() == other.get();
}

/// \brief construct a reference to a mutable object.
template<typename Type>
inline Reference<Type> makeReference(Type& value)
{
  return Reference<Type>(value);
}

/// \brief A reference to a non-mutable object.
/// Has 'reference' semantics, except for \c 'operator==' and \c 'operator.'.
/// \param Type The type of the referenced object.
template<typename Type>
class ConstReference
{
  const Type* m_contained;
public:
  explicit ConstReference(const Type& contained) : m_contained(&contained)
  {
  }
  const Type& operator*() const
  {
    return *m_contained;
  }
  const Type* operator->() const
  {
    return m_contained;
  }
  operator const Type&() const
  {
    return *m_contained;
  }
  const Type& get() const
  {
    return *m_contained;
  }
  const Type* get_pointer() const
  {
    return m_contained;
  }
};

template<typename Type>
bool operator<(const ConstReference<Type>& self, const ConstReference<Type>& other)
{
  return self.get() < other.get();
}
template<typename Type>
bool operator==(const ConstReference<Type>& self, const ConstReference<Type>& other)
{
  return self.get() == other.get();
}

/// \brief construct a reference to a non-mutable object.
template<typename Type>
inline ConstReference<Type> makeReference(const Type& value)
{
  return ConstReference<Type>(value);
}


#endif