static const int SIZE = 16;

inline uint16_t &operator[] (int y)
{
    return bits[y];
}
void clear()
{
    memset(bits,0,sizeof(bits));
}
void set_all()
{
    memset(bits,0xFF,sizeof(bits));
}
inline bool getassignment( const df::coord2d &xy )
{
    return getassignment(xy.x,xy.y);
}
inline bool getassignment( int x, int y )
{
    return (bits[(y&15)] & (1 << (x&15)));
}
inline void setassignment( const df::coord2d &xy, bool bit )
{
    return setassignment(xy.x,xy.y, bit);
}
inline void setassignment( int x, int y, bool bit )
{
    if(bit)
        bits[(y&15)] |= (1 << (x&15));
    else
        bits[(y&15)] &= ~(1 << (x&15));
}
bool has_assignments()
{
    for (int i = 0; i < 16; i++)
        if (bits[i])
            return true;
    return false;
}
df::tile_bitmask &operator |= (const df::tile_bitmask &b) {
    for (int i = 0; i < 16; i++)
        bits[i] |= b.bits[i];
    return *this;
}
df::tile_bitmask &operator &= (const df::tile_bitmask &b) {
    for (int i = 0; i < 16; i++)
        bits[i] &= b.bits[i];
    return *this;
}
df::tile_bitmask &operator -= (const df::tile_bitmask &b) {
    for (int i = 0; i < 16; i++)
        bits[i] &= ~b.bits[i];
    return *this;
}