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ERC20PermitUpgradeable

Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in https://eips.ethereum.org/EIPS/eip-2612. Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't need to send a transaction, and thus is not required to hold Ether at all. Available since v3.4.

Methods​

DOMAIN_SEPARATOR​

function DOMAIN_SEPARATOR() external view returns (bytes32)

See {IERC20Permit-DOMAIN_SEPARATOR}.

Returns​

NameTypeDescription
_0bytes32undefined

allowance​

function allowance(address owner, address spender) external view returns (uint256)

See {IERC20-allowance}.

Parameters​

NameTypeDescription
owneraddressundefined
spenderaddressundefined

Returns​

NameTypeDescription
_0uint256undefined

approve​

function approve(address spender, uint256 amount) external nonpayable returns (bool)

See {IERC20-approve}. NOTE: If amount is the maximum uint256, the allowance is not updated on transferFrom. This is semantically equivalent to an infinite approval. Requirements: - spender cannot be the zero address.

Parameters​

NameTypeDescription
spenderaddressundefined
amountuint256undefined

Returns​

NameTypeDescription
_0boolundefined

balanceOf​

function balanceOf(address account) external view returns (uint256)

See {IERC20-balanceOf}.

Parameters​

NameTypeDescription
accountaddressundefined

Returns​

NameTypeDescription
_0uint256undefined

decimals​

function decimals() external view returns (uint8)

Returns the number of decimals used to get its user representation. For example, if decimals equals 2, a balance of 505 tokens should be displayed to a user as 5.05 (505 / 10 ** 2). Tokens usually opt for a value of 18, imitating the relationship between Ether and Wei. This is the value {ERC20} uses, unless this function is overridden; NOTE: This information is only used for display purposes: it in no way affects any of the arithmetic of the contract, including {IERC20-balanceOf} and {IERC20-transfer}.

Returns​

NameTypeDescription
_0uint8undefined

decreaseAllowance​

function decreaseAllowance(address spender, uint256 subtractedValue) external nonpayable returns (bool)

Atomically decreases the allowance granted to spender by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements: - spender cannot be the zero address. - spender must have allowance for the caller of at least subtractedValue.

Parameters​

NameTypeDescription
spenderaddressundefined
subtractedValueuint256undefined

Returns​

NameTypeDescription
_0boolundefined

increaseAllowance​

function increaseAllowance(address spender, uint256 addedValue) external nonpayable returns (bool)

Atomically increases the allowance granted to spender by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements: - spender cannot be the zero address.

Parameters​

NameTypeDescription
spenderaddressundefined
addedValueuint256undefined

Returns​

NameTypeDescription
_0boolundefined

name​

function name() external view returns (string)

Returns the name of the token.

Returns​

NameTypeDescription
_0stringundefined

nonces​

function nonces(address owner) external view returns (uint256)

See {IERC20Permit-nonces}.

Parameters​

NameTypeDescription
owneraddressundefined

Returns​

NameTypeDescription
_0uint256undefined

permit​

function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external nonpayable

See {IERC20Permit-permit}.

Parameters​

NameTypeDescription
owneraddressundefined
spenderaddressundefined
valueuint256undefined
deadlineuint256undefined
vuint8undefined
rbytes32undefined
sbytes32undefined

symbol​

function symbol() external view returns (string)

Returns the symbol of the token, usually a shorter version of the name.

Returns​

NameTypeDescription
_0stringundefined

totalSupply​

function totalSupply() external view returns (uint256)

See {IERC20-totalSupply}.

Returns​

NameTypeDescription
_0uint256undefined

transfer​

function transfer(address to, uint256 amount) external nonpayable returns (bool)

See {IERC20-transfer}. Requirements: - to cannot be the zero address. - the caller must have a balance of at least amount.

Parameters​

NameTypeDescription
toaddressundefined
amountuint256undefined

Returns​

NameTypeDescription
_0boolundefined

transferFrom​

function transferFrom(address from, address to, uint256 amount) external nonpayable returns (bool)

See {IERC20-transferFrom}. Emits an {Approval} event indicating the updated allowance. This is not required by the EIP. See the note at the beginning of {ERC20}. NOTE: Does not update the allowance if the current allowance is the maximum uint256. Requirements: - from and to cannot be the zero address. - from must have a balance of at least amount. - the caller must have allowance for from's tokens of at least amount.

Parameters​

NameTypeDescription
fromaddressundefined
toaddressundefined
amountuint256undefined

Returns​

NameTypeDescription
_0boolundefined

Events​

Approval​

event Approval(address indexed owner, address indexed spender, uint256 value)

Parameters​

NameTypeDescription
owner indexedaddressundefined
spender indexedaddressundefined
valueuint256undefined

Initialized​

event Initialized(uint8 version)

Parameters​

NameTypeDescription
versionuint8undefined

Transfer​

event Transfer(address indexed from, address indexed to, uint256 value)

Parameters​

NameTypeDescription
from indexedaddressundefined
to indexedaddressundefined
valueuint256undefined