ERC20Permit

Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in https://eips.ethereum.org/EIPS/eip-2612[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

Name
Type
Description

_0

bytes32

undefined

allowance

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

See {IERC20-allowance}.

Parameters

Name
Type
Description

owner

address

undefined

spender

address

undefined

Returns

Name
Type
Description

_0

uint256

undefined

approve

See {IERC20-approve}. Requirements: - spender cannot be the zero address.

Parameters

Name
Type
Description

spender

address

undefined

amount

uint256

undefined

Returns

Name
Type
Description

_0

bool

undefined

balanceOf

See {IERC20-balanceOf}.

Parameters

Name
Type
Description

account

address

undefined

Returns

Name
Type
Description

_0

uint256

undefined

decimals

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 {_setupDecimals} is called. 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

Name
Type
Description

_0

uint8

undefined

decreaseAllowance

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

Name
Type
Description

spender

address

undefined

subtractedValue

uint256

undefined

Returns

Name
Type
Description

_0

bool

undefined

increaseAllowance

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

Name
Type
Description

spender

address

undefined

addedValue

uint256

undefined

Returns

Name
Type
Description

_0

bool

undefined

name

Returns the name of the token.

Returns

Name
Type
Description

_0

string

undefined

nonces

See {IERC20Permit-nonces}.

Parameters

Name
Type
Description

owner

address

undefined

Returns

Name
Type
Description

_0

uint256

undefined

permit

See {IERC20Permit-permit}.

Parameters

Name
Type
Description

owner

address

undefined

spender

address

undefined

value

uint256

undefined

deadline

uint256

undefined

v

uint8

undefined

r

bytes32

undefined

s

bytes32

undefined

symbol

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

Returns

Name
Type
Description

_0

string

undefined

totalSupply

See {IERC20-totalSupply}.

Returns

Name
Type
Description

_0

uint256

undefined

transfer

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

Parameters

Name
Type
Description

recipient

address

undefined

amount

uint256

undefined

Returns

Name
Type
Description

_0

bool

undefined

transferFrom

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}. Requirements: - sender and recipient cannot be the zero address. - sender must have a balance of at least amount. - the caller must have allowance for sender's tokens of at least amount.

Parameters

Name
Type
Description

sender

address

undefined

recipient

address

undefined

amount

uint256

undefined

Returns

Name
Type
Description

_0

bool

undefined

Events

Approval

Parameters

Name
Type
Description

owner indexed

address

undefined

spender indexed

address

undefined

value

uint256

undefined

Transfer

Parameters

Name
Type
Description

from indexed

address

undefined

to indexed

address

undefined

value

uint256

undefined

Last updated

Was this helpful?