BitMaps

*Library for managing uint256 to bool mapping in a compact and efficient way, provided the keys are sequential. Largely inspired by Uniswap's https://github.com/Uniswap/merkle-distributor/blob/master/contracts/MerkleDistributor.sol[merkle-distributor]. BitMaps pack 256 booleans across each bit of a single 256-bit slot of uint256 type. Hence booleans corresponding to 256 sequential indices would only consume a single slot, unlike the regular bool which would consume an entire slot for a single value. This results in gas savings in two ways:

• Setting a zero value to non-zero only once every 256 times
• Accessing the same warm slot for every 256 sequential indices*

Functions

get

Returns whether the bit at index is set.

function get(BitMap storage bitmap, uint256 index) internal view returns (bool);

setTo

Sets the bit at index to the boolean value.

function setTo(BitMap storage bitmap, uint256 index, bool value) internal;

set

Sets the bit at index.

function set(BitMap storage bitmap, uint256 index) internal;

unset

Unsets the bit at index.

function unset(BitMap storage bitmap, uint256 index) internal;

Structs

BitMap

struct BitMap {
    mapping(uint256 bucket => uint256) _data;
}