57 lines
1.8 KiB
Solidity
57 lines
1.8 KiB
Solidity
// SPDX-License-Identifier: MIT
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// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/ERC20Burnable.sol)
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pragma solidity ^0.8.0;
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import "../ERC20Upgradeable.sol";
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import "../../../utils/ContextUpgradeable.sol";
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import "../../../proxy/utils/Initializable.sol";
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/**
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* @dev Extension of {ERC20} that allows token holders to destroy both their own
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* tokens and those that they have an allowance for, in a way that can be
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* recognized off-chain (via event analysis).
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*/
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abstract contract ERC20BurnableUpgradeable is Initializable, ContextUpgradeable, ERC20Upgradeable {
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function __ERC20Burnable_init() internal onlyInitializing {
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}
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function __ERC20Burnable_init_unchained() internal onlyInitializing {
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}
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/**
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* @dev Destroys `amount` tokens from the caller.
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*
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* See {ERC20-_burn}.
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*/
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function burn(uint256 amount) public virtual {
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_burn(_msgSender(), amount);
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}
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/**
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* @dev Destroys `amount` tokens from `account`, deducting from the caller's
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* allowance.
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*
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* See {ERC20-_burn} and {ERC20-allowance}.
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*
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* Requirements:
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*
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* - the caller must have allowance for ``accounts``'s tokens of at least
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* `amount`.
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*/
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function burnFrom(address account, uint256 amount) public virtual {
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uint256 currentAllowance = allowance(account, _msgSender());
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require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
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unchecked {
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_approve(account, _msgSender(), currentAllowance - amount);
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}
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_burn(account, amount);
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}
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/**
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* This empty reserved space is put in place to allow future versions to add new
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* variables without shifting down storage in the inheritance chain.
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* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
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*/
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uint256[50] private __gap;
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}
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