13
0
livetrax/libs/audiographer/audiographer/flag_field.h
2010-03-15 19:11:48 +00:00

106 lines
3.2 KiB
C++

#ifndef AUDIOGRAPHER_FLAG_FIELD_H
#define AUDIOGRAPHER_FLAG_FIELD_H
#include <stdint.h>
#include <iterator>
#include <climits>
#include <boost/operators.hpp>
namespace AudioGrapher {
/** Flag field capable of holding 32 flags.
* Easily grown in size to 64 flags by changing storage_type.
*/
class FlagField
: public boost::less_than_comparable<FlagField>
, boost::equivalent<FlagField>
, boost::equality_comparable<FlagField>
{
public:
typedef uint8_t Flag;
typedef uint32_t storage_type;
/// Bi-directional iterator for flag set. Iterates over flags that are set in this field.
class iterator
: public std::iterator<std::bidirectional_iterator_tag, Flag>
, public boost::less_than_comparable<iterator>
, boost::equivalent<iterator>
, boost::equality_comparable<iterator>
{
public:
iterator (FlagField const & parent, Flag position) : parent (parent), position (position) {}
iterator (iterator const & other) : parent (other.parent), position (other.position) {}
value_type operator*() const { return position; }
value_type const * operator->() const { return &position; }
iterator & operator++()
{
do {
++position;
} while (!parent.has (position) && position != max());
return *this;
}
iterator operator++(int) { iterator copy (*this); ++(*this); return copy; }
iterator & operator--()
{
do {
--position;
} while (!parent.has (position) && position != max());
return *this;
}
iterator operator--(int) { iterator copy (*this); --(*this); return copy; }
bool operator< (iterator const & other) const { return position < other.position; }
private:
FlagField const & parent;
Flag position;
};
public:
FlagField() : _flags (0) {}
FlagField(FlagField const & other) : _flags (other._flags) {}
inline bool has (Flag flag) const { return _flags & (1 << flag); }
inline storage_type flags () const { return _flags; }
inline operator bool() const { return _flags; }
inline void set (Flag flag) { _flags |= (1 << flag); }
inline void remove (Flag flag) { _flags &= ~(1 << flag); }
inline void reset () { _flags = 0; }
/// Returns the flags in \a other that are not set in this field
inline FlagField unsupported_flags_of (FlagField const & other) const { return ~(_flags | ~other._flags); }
/// Set all flags that are set in \a other
inline FlagField & operator+= (FlagField const & other) { _flags |= other._flags; return *this; }
/** Checks whether this field has all the flags set that are set in \a other
* NOTE: Can NOT be used for strict weak ordering!
* \return \a true if \a other has flags set that this field does not
*/
inline bool operator< (FlagField const & other) const { return unsupported_flags_of (other); }
iterator begin() const
{
iterator it (*this, 0);
if (!*this) { return end(); }
if (!has (0)) { ++it; }
return it;
}
iterator end() const { iterator it (*this, max()); return it; }
private:
FlagField(storage_type flags) : _flags (flags) {}
static Flag max() { return CHAR_BIT * sizeof (storage_type) + 1; }
storage_type _flags;
};
} // namespace
#endif // AUDIOGRAPHER_FLAG_FIELD_H