OpenZeppelin/openzeppelin-contracts v4.2.0

on GitHub

Read the full announcement in the blog!

• ERC20Votes: add a new extension of the ERC20 token with support for voting snapshots and delegation. (#2632)
• ERC20VotesComp: Variant of ERC20Votes that is compatible with Compound's Comp token interface but restricts supply to uint96. (#2706)
• ERC20Wrapper: add a new extension of the ERC20 token which wraps an underlying token. Deposit and withdraw guarantee that the total supply is backed by a corresponding amount of underlying token. (#2633)
• Enumerables: Improve gas cost of removal in EnumerableSet and EnumerableMap.
• Enumerables: Improve gas cost of lookup in EnumerableSet and EnumerableMap.
• Counter: add a reset method. (#2678)
• Tokens: Wrap definitely safe subtractions in unchecked blocks.
• Math: Add a ceilDiv method for performing ceiling division.
• ERC1155Supply: add a new ERC1155 extension that keeps track of the totalSupply of each tokenId. (#2593)
• BitMaps: add a new BitMaps library that provides a storage efficient datastructure for uint256 to bool mapping with contiguous keys. (#2710)

Breaking Changes

• ERC20FlashMint is no longer a Draft ERC. (#2673))

How to update: Change your import paths by removing the draft- prefix from @openzeppelin/contracts/token/ERC20/extensions/draft-ERC20FlashMint.sol.

See Releases and Stability: Drafts.