Cursor &Cursor::operator++()
{
// Either this is the end cursor, or the current position is valid.
assert(piece == pieceEnd || position != piece->end);
// If we are already the end cursor, don't move.
if(piece == pieceEnd)
return *this;
// Increment the position. If we've reached the end of the piece,
// move to the next piece and reset the position instead. If there
// are no more piece, just reset to being the end cursor instead.
++position;
if(position == piece->end)
{
++piece;
if(piece == pieceEnd)
position = PositionIterator();
else
position = piece->begin;
}
return *this;
}
PositionIterator positions() { return PositionIterator(h, w); }