vmap/libs/generic/bitfield.h

/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined( INCLUDED_GENERIC_BITFIELD_H )
#define INCLUDED_GENERIC_BITFIELD_H

/// \file
/// \brief Type safe bitfield.

/// \brief A bit-field value.
///
/// - Can be forward-declared when the definition of Enumeration is unknown.
/// - Can only be constructed from valid enumerated values.
/// - Can only be compared and combined with others of the same type.
///
/// \param Enumeration A type that contains an enum \c Value of the bits that can be set in this field.
template<typename Enumeration>
class BitFieldValue : public Enumeration
{
unsigned m_value;
protected:
explicit BitFieldValue( unsigned value ) : m_value( value ){
}
public:
BitFieldValue() : m_value( 0 ){
}
explicit BitFieldValue( typename Enumeration::Value value ) : m_value( 1 << value ){
}
unsigned get() const {
	return m_value;
}
};

template<typename Enumeration>
class BitFieldValueUnsafe : public BitFieldValue<Enumeration>
{
public:
explicit BitFieldValueUnsafe( unsigned value ) : BitFieldValue<Enumeration>( value ){
}
};

template<typename Enumeration>
inline bool operator==( BitFieldValue<Enumeration> self, BitFieldValue<Enumeration> other ){
	return self.get() == other.get();
}
template<typename Enumeration>
inline bool operator!=( BitFieldValue<Enumeration> self, BitFieldValue<Enumeration> other ){
	return !operator==( self, other );
}

template<typename Enumeration>
inline BitFieldValue<Enumeration> operator|( BitFieldValue<Enumeration> self, BitFieldValue<Enumeration> other ){
	return BitFieldValueUnsafe<Enumeration>( self.get() | other.get() );
}
template<typename Enumeration>
inline BitFieldValue<Enumeration>& operator|=( BitFieldValue<Enumeration>& self, BitFieldValue<Enumeration> other ){
	return self = self | other;
}
template<typename Enumeration>
inline BitFieldValue<Enumeration> operator&( BitFieldValue<Enumeration> self, BitFieldValue<Enumeration> other ){
	return BitFieldValueUnsafe<Enumeration>( self.get() & other.get() );
}
template<typename Enumeration>
inline BitFieldValue<Enumeration>& operator&=( BitFieldValue<Enumeration>& self, BitFieldValue<Enumeration> other ){
	return self = self & other;
}
template<typename Enumeration>
inline BitFieldValue<Enumeration> operator~( BitFieldValue<Enumeration> self ){
	return BitFieldValueUnsafe<Enumeration>( ~self.get() );
}



inline unsigned int bitfield_enable( unsigned int bitfield, unsigned int mask ){
	return bitfield | mask;
}
inline unsigned int bitfield_disable( unsigned int bitfield, unsigned int mask ){
	return bitfield & ~mask;
}
inline bool bitfield_enabled( unsigned int bitfield, unsigned int mask ){
	return ( bitfield & mask ) != 0;
}

template<typename Enumeration>
inline BitFieldValue<Enumeration> bitfield_enable( BitFieldValue<Enumeration> bitfield, BitFieldValue<Enumeration> mask ){
	return bitfield | mask;
}
template<typename Enumeration>
inline BitFieldValue<Enumeration> bitfield_disable( BitFieldValue<Enumeration> bitfield, BitFieldValue<Enumeration> mask ){
	return bitfield & ~mask;
}
template<typename Enumeration>
inline bool bitfield_enabled( BitFieldValue<Enumeration> bitfield, BitFieldValue<Enumeration> mask ){
	return ( bitfield & mask ).get() != 0;
}

#endif