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
See {IERC20Permit-DOMAIN_SEPARATOR}.
Returns
Name | Type | Description |
---|---|---|
_0 | bytes32 | undefined |
allowance
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 | address | undefined |
spender | address | undefined |
value | uint256 | undefined |
Transfer
Parameters
Name | Type | Description |
---|---|---|
from | address | undefined |
to | address | undefined |
value | uint256 | undefined |
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