IERC20PermitAllowed
Interface used by DAI/CHAI for permit
Functions#
permit#
  function permit(    address holder,    address spender,    uint256 nonce,    uint256 expiry,    bool allowed,    uint8 v,    bytes32 r,    bytes32 s  ) externalApprove the spender to spend some tokens via the holder signature
This is the permit interface used by DAI and CHAI
Parameters:#
| Name | Type | Description | 
|---|---|---|
| holder | address | The address of the token holder, the token owner | 
| spender | address | The address of the token spender | 
| nonce | uint256 | The holder's nonce, increases at each call to permit | 
| expiry | uint256 | The timestamp at which the permit is no longer valid | 
| allowed | bool | Boolean that sets approval amount, true for type(uint256).max and false for 0 | 
| v | uint8 | Must produce valid secp256k1 signature from the holder along with rands | 
| r | bytes32 | Must produce valid secp256k1 signature from the holder along with vands | 
| s | bytes32 | Must produce valid secp256k1 signature from the holder along with randv |