Copy
91/**
92    @notice Burns the current balance of the contract
93    @dev This function will burn the current balance of the contract
94*/
95function _burnSelf() internal virtual {
96    uint256 selfBalance = balanceOf(address(this));
97    if (selfBalance > 0) {
98        _burn(address(this), selfBalance);
99        emit Burned(msg.sender, selfBalance);
100    }
101}
102
103/**
104    @notice Override of the `_update()` function from the ERC-20 implementation
105    @dev Adds special constraints to ensure that tokens can only be transferred
106      to the allowed recipient or the contract itself:
107        - recipient != address(this): in circulation
108        - recipient == address(this): out of circulation
109*/
110function _update(
111    address from,
112    address to,
113    uint256 amount
114) internal virtual override {
115    if (!(to == address(this) || to == permittedRecipient)) {
116        revert ErrorLib.RecipientNotPermitted(to);
117    }
118    super._update(from, to, amount);
119
120    if (to == address(this))
121        emit TokenDeallocated(msg.sender, from, amount);
122
123    /// Resets `permittedRecipient` to address(0) as a security measure to prevent
124    /// potential reuse of the previously permitted address in subsequent transactions,
125    /// in accordance with EIP-1153 transient storage best practices:
126    /// https://eips.ethereum.org/EIPS/eip-1153#security-considerations
127    permittedRecipient = address(0);
128}