ERC20TemporaryApprovalUpgradeable

Inherits: Initializable, ERC20Upgradeable, IERC7674

Extension of {ERC20} that adds support for temporary allowances following ERC-7674. WARNING: This is a draft contract. The corresponding ERC is still subject to changes. Available since v5.1.

State Variables

ERC20_TEMPORARY_APPROVAL_STORAGE

bytes32 private constant ERC20_TEMPORARY_APPROVAL_STORAGE =
    0xea2d0e77a01400d0111492b1321103eed560d8fe44b9a7c2410407714583c400;

Functions

__ERC20TemporaryApproval_init

function __ERC20TemporaryApproval_init() internal onlyInitializing;

__ERC20TemporaryApproval_init_unchained

function __ERC20TemporaryApproval_init_unchained() internal onlyInitializing;

allowance

allowance override that includes the temporary allowance when looking up the current allowance. If adding up the persistent and the temporary allowances result in an overflow, type(uint256).max is returned.

function allowance(address owner, address spender)
    public
    view
    virtual
    override(IERC20, ERC20Upgradeable)
    returns (uint256);

_temporaryAllowance

Internal getter for the current temporary allowance that spender has over owner tokens.

function _temporaryAllowance(address owner, address spender) internal view virtual returns (uint256);

temporaryApprove

*Alternative to {approve} that sets a value amount of tokens as the temporary allowance of spender over the caller's tokens. Returns a boolean value indicating whether the operation succeeded. Requirements:

• spender cannot be the zero address. Does NOT emit an {Approval} event.*

function temporaryApprove(address spender, uint256 value) public virtual returns (bool);

_temporaryApprove

*Sets value as the temporary allowance of spender over the owner's tokens. This internal function is equivalent to temporaryApprove, and can be used to e.g. set automatic allowances for certain subsystems, etc. Requirements:

• owner cannot be the zero address.
• spender cannot be the zero address. Does NOT emit an {Approval} event.*

function _temporaryApprove(address owner, address spender, uint256 value) internal virtual;

_spendAllowance

_spendAllowance override that consumes the temporary allowance (if any) before eventually falling back to consuming the persistent allowance. NOTE: This function skips calling super._spendAllowance if the temporary allowance is enough to cover the spending.

function _spendAllowance(address owner, address spender, uint256 value) internal virtual override;

_temporaryAllowanceSlot

function _temporaryAllowanceSlot(address owner, address spender) private pure returns (TransientSlot.Uint256Slot);