BitMap

internal function hasBit

function hasBit(uint256 bitmap, uint8 index) internal pure returns (bool)

Input	Type	Description
bitmap	uint256	The uint256 representation of bits.
index	uint8	The index number to check whether 1 or 0 is set.
Output
0	bool	Returns true if the bit is set at index on bitmap.

internal function flipBit

function flipBit(uint256 bitmap, uint8 index) internal pure returns (uint256)

Input	Type	Description
bitmap	uint256	The uint256 representation of bits.
index	uint8	The index number to set the bit.
Output
0	uint256	Returns a new number in which the bit is set at index.