ERC20Votes

Git Source

Inherits: IERC20Votes

Title: ERC20Votes

Author: Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/extensions/ERC20Votes.sol)

Stateless Diamond facet combining ERC-20 with checkpoint-based voting power.

Hook model (D25, #234): replacing transfer/transferFrom makes this facet mutually exclusive with every other facet that replaces them (ERC20Pausable; GovernedVault, which supersedes it in DeployGovernedVault). A direct mover beside it (ERC20Burnable, ERC20FlashMint, ERC20Crosschain, ERC20Wrapper, ERC7802, ERC4626, VaultCore, or a mint facet over ERC20Capped's _mint) mints and burns without moving voting units, so delegated votes drift from the supply. The sanctioned mint/burn path is a facet that calls ERC20VotesLib._mint/ERC20VotesLib._burn, which checkpoint votes and enforce the uint208 supply bound. See docs/guides/selector-compatibility.md#token-extension-hook-model.

Callers must initialize the following modules in their initializer:

• ERC20Lib.__ERC20_init(name, symbol)
• EIP712Lib.__EIP712_init(name, version)
• NoncesLib.__Nonces_init()
• VotesLib.__Votes_init()

Differences from OpenZeppelin v5.6.1:

• OpenZeppelin moves voting units in _update, so every mint, burn and transfer moves votes. Here only this facet's transfer/transferFrom and ERC20VotesLib._mint/ERC20VotesLib._burn do. Movement through ERC20Lib from another facet (ERC20Burnable, ERC20FlashMint, ERC20Wrapper, ERC20Crosschain, ERC7802, ERC1363, ERC4626 outside GovernedVault) does not, so those are mutually exclusive with this facet (decision D25 on #234).
• The type(uint208).max supply check runs only in ERC20VotesLib._mint.
• The clock is block.timestamp (Votes), not the block number.
• numCheckpoints narrows the length with a plain uint32 cast rather than SafeCast.toUint32; 2^32 checkpoints are unreachable.
• ERC20VotesInit registers IVotes for ERC-165 (through VotesLib.__Votes_init); OpenZeppelin's extension has no ERC-165.

Notes:

• lattice-version: 0.1.0
• lattice-source: OpenZeppelin v5.6.1

Functions

transfer

Transfers, updating vote checkpoints alongside balances (replaces the base transfer).

function transfer(address to, uint256 value) public virtual returns (bool);

Parameters

Returns

transferFrom

Transfers from, updating vote checkpoints alongside balances (replaces the base transferFrom).

function transferFrom(address from, address to, uint256 value) public virtual returns (bool);

Parameters

Returns

delegate

Delegates votes from the caller to delegatee (replaces the base Votes variant).

function delegate(address delegatee) public virtual;

Parameters

delegateBySig

Delegates votes from the signer to delegatee via EIP-712 (replaces the base Votes variant).

function delegateBySig(address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s)
        public
        virtual;

Parameters

numCheckpoints

Returns the number of checkpoints for account.

function numCheckpoints(address account) public view virtual returns (uint32);

Parameters

Returns

checkpoints

Returns the checkpoint at position pos for account (0-indexed).

function checkpoints(address account, uint32 pos) public view virtual returns (Checkpoints.Checkpoint208 memory);

Parameters

Returns

exportSelectors

ERC-8153 selector export: this facet's cuttable selectors, tightly packed (4 bytes each).

function exportSelectors() external pure virtual returns (bytes memory selectors);

Returns