{{
"language": "Solidity",
"sources": {
"contracts/NanoByteToken.sol": {
"content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./libs/BEP20Capped.sol\";\n// NBT with Governance.\ncontract NanoByteToken is BEP20Capped {\n using SafeMath for uint256;\n \n constructor() BEP20('NanoByte Token','NBT') BEP20Capped(10000000000000000000000000000) {}\n\n function mint(uint256 _amount) external onlyOwner override returns (bool) {\n _mint(_msgSender(), _amount);\n _moveDelegates(address(0), _delegates[_msgSender()], _amount);\n return true;\n }\n\n function mint(address _to, uint256 _amount) external onlyOwner {\n _mint(_to, _amount);\n _moveDelegates(address(0), _delegates[_to], _amount);\n }\n\n function burn(uint256 _amount) external {\n _burn(_msgSender(), _amount);\n _moveDelegates(_delegates[_msgSender()], address(0), _amount);\n }\n\n function burnFrom(address _from, uint256 _amount) external{\n _burnFrom(_from, _amount);\n _moveDelegates(_delegates[_from], address(0), _amount);\n }\n\n\n // transfers delegate authority when sending a token.\n // https://medium.com/bulldax-finance/sushiswap-delegation-double-spending-bug-5adcc7b3830f\n function _transfer(address sender, address recipient, uint256 amount) internal override virtual {\n super._transfer(sender, recipient, amount);\n _moveDelegates(_delegates[sender], _delegates[recipient], amount);\n }\n\n\n // Copied and modified from YAM code:\n // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol\n // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol\n // Which is copied and modified from COMPOUND:\n // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol\n\n /// @notice A record of each accounts delegate\n mapping (address => address) internal _delegates;\n\n /// @notice A checkpoint for marking number of votes from a given block\n struct Checkpoint {\n uint32 fromBlock;\n uint256 votes;\n }\n\n /// @notice A record of votes checkpoints for each account, by index\n mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;\n\n /// @notice The number of checkpoints for each account\n mapping (address => uint32) public numCheckpoints;\n\n /// @notice The EIP-712 typehash for the contract's domain\n bytes32 public constant DOMAIN_TYPEHASH = keccak256(\"EIP712Domain(string name,uint256 chainId,address verifyingContract)\");\n\n /// @notice The EIP-712 typehash for the delegation struct used by the contract\n bytes32 public constant DELEGATION_TYPEHASH = keccak256(\"Delegation(address delegatee,uint256 nonce,uint256 expiry)\");\n\n /// @notice A record of states for signing / validating signatures\n mapping (address => uint) public nonces;\n\n /// @notice An event thats emitted when an account changes its delegate\n event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);\n\n /// @notice An event thats emitted when a delegate account's vote balance changes\n event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);\n\n /**\n * @notice Gets associated delegatee given the delegator`\n * @param delegator The address to get delegatee for\n * @return The delegator of the delegate\n */\n function delegates(address delegator)\n external\n view\n returns (address)\n {\n return _delegates[delegator];\n }\n\n /**\n * @notice Delegate votes from `msg.sender` to `delegatee`\n * @param delegatee The address to delegate votes to\n */\n function delegate(address delegatee) external {\n _delegate(msg.sender, delegatee);\n }\n\n /**\n * @notice Delegates votes from signatory to `delegatee`\n * @param delegatee The address to delegate votes to\n * @param nonce The contract state required to match the signature\n * @param expiry The time at which to expire the signature\n * @param v The recovery byte of the signature\n * @param r Half of the ECDSA signature pair\n * @param s Half of the ECDSA signature pair\n */\n function delegateBySig(\n address delegatee,\n uint nonce,\n uint expiry,\n uint8 v,\n bytes32 r,\n bytes32 s\n )\n external\n {\n bytes32 domainSeparator = keccak256(\n abi.encode(\n DOMAIN_TYPEHASH,\n keccak256(bytes(name())),\n getChainId(),\n address(this)\n )\n );\n\n bytes32 structHash = keccak256(\n abi.encode(\n DELEGATION_TYPEHASH,\n delegatee,\n nonce,\n expiry\n )\n );\n\n bytes32 digest = keccak256(\n abi.encodePacked(\n \"\\x19\\x01\",\n domainSeparator,\n structHash\n )\n );\n\n address signatory = ecrecover(digest, v, r, s);\n require(signatory != address(0), \"NBT::delegateBySig: invalid signature\");\n require(nonce == nonces[signatory], \"NBT::delegateBySig: invalid nonce\");\n \n nonces[signatory] ;\n\n require(block.timestamp <= expiry, \"NBT::delegateBySig: signature expired\");\n _delegate(signatory, delegatee);\n }\n\n /**\n * @notice Gets the current votes balance for `account`\n * @param account The address to get votes balance\n * @return The number of current votes for `account`\n */\n function getCurrentVotes(address account)\n external\n view\n returns (uint256)\n {\n uint32 nCheckpoints = numCheckpoints[account];\n return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;\n }\n\n /**\n * @notice Determine the prior number of votes for an account as of a block number\n * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.\n * @param account The address of the account to check\n * @param blockNumber The block number to get the vote balance at\n * @return The number of votes the account had as of the given block\n */\n function getPriorVotes(address account, uint blockNumber)\n external\n view\n returns (uint256)\n {\n require(blockNumber < block.number, \"NBT::getPriorVotes: not yet determined\");\n\n uint32 nCheckpoints = numCheckpoints[account];\n if (nCheckpoints == 0) {\n return 0;\n }\n\n // First check most recent balance\n if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {\n return checkpoints[account][nCheckpoints - 1].votes;\n }\n\n // Next check implicit zero balance\n if (checkpoints[account][0].fromBlock > blockNumber) {\n return 0;\n }\n\n uint32 lower = 0;\n uint32 upper = nCheckpoints - 1;\n while (upper > lower) {\n uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow\n Checkpoint memory cp = checkpoints[account][center];\n if (cp.fromBlock == blockNumber) {\n return cp.votes;\n } else if (cp.fromBlock < blockNumber) {\n lower = center;\n } else {\n upper = center - 1;\n }\n }\n return checkpoints[account][lower].votes;\n }\n\n function _delegate(address delegator, address delegatee)\n internal\n {\n address currentDelegate = _delegates[delegator];\n uint256 delegatorBalance = balanceOf(delegator); // balance of underlying NBTs (not scaled);\n _delegates[delegator] = delegatee;\n\n emit DelegateChanged(delegator, currentDelegate, delegatee);\n\n _moveDelegates(currentDelegate, delegatee, delegatorBalance);\n }\n\n function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal {\n if (srcRep != dstRep && amount > 0) {\n if (srcRep != address(0)) {\n // decrease old representative\n uint32 srcRepNum = numCheckpoints[srcRep];\n uint256 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;\n uint256 srcRepNew = srcRepOld.sub(amount);\n _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);\n }\n\n if (dstRep != address(0)) {\n // increase new representative\n uint32 dstRepNum = numCheckpoints[dstRep];\n uint256 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;\n uint256 dstRepNew = dstRepOld.add(amount);\n _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);\n }\n }\n }\n\n function _writeCheckpoint(\n address delegatee,\n uint32 nCheckpoints,\n uint256 oldVotes,\n uint256 newVotes\n )\n internal\n {\n uint32 blockNumber = safe32(block.number, \"NBT::_writeCheckpoint: block number exceeds 32 bits\");\n\n if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {\n checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;\n } else {\n checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);\n numCheckpoints[delegatee] = nCheckpoints 1;\n }\n\n emit DelegateVotesChanged(delegatee, oldVotes, newVotes);\n }\n\n function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {\n require(n < 2**32, errorMessage);\n return uint32(n);\n }\n\n function getChainId() internal view returns (uint) {\n uint256 chainId;\n assembly { chainId := chainid() }\n return chainId;\n }\n}"
},
"contracts/libs/BEP20Capped.sol": {
"content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.3.2 (token/ERC20/extensions/ERC20Capped.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./BEP20.sol\";\n\n/**\n * @dev Extension of {ERC20} that adds a cap to the supply of tokens.\n */\nabstract contract BEP20Capped is BEP20 {\n uint256 private immutable _cap;\n\n /**\n * @dev Sets the value of the `cap`. This value is immutable, it can only be\n * set once during construction.\n */\n constructor(uint256 cap_) {\n require(cap_ > 0, \"BEP20Capped: cap is 0\");\n _cap = cap_;\n }\n\n /**\n * @dev Returns the cap on the token's total supply.\n */\n function cap() public view virtual returns (uint256) {\n return _cap;\n }\n\n /**\n * @dev See {ERC20-_mint}.\n */\n function _mint(address account, uint256 amount) internal virtual override {\n require(BEP20.totalSupply() amount <= cap(), \"BEP20Capped: cap exceeded\");\n super._mint(account, amount);\n }\n}\n"
},
"contracts/libs/BEP20.sol": {
"content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport '@openzeppelin/contracts/access/Ownable.sol';\nimport '@openzeppelin/contracts/utils/Context.sol';\nimport './IBEP20.sol';\nimport '@openzeppelin/contracts/utils/math/SafeMath.sol';\n\n/**\n * @dev Implementation of the {IBEP20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {BEP20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-BEP20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of BEP20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn't required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IBEP20-approve}.\n */\ncontract BEP20 is Context, IBEP20, Ownable {\n using SafeMath for uint256;\n\n mapping(address => uint256) private _balances;\n\n mapping(address => mapping(address => uint256)) private _allowances;\n\n uint256 private _totalSupply;\n\n string private _name;\n string private _symbol;\n uint8 private _decimals;\n\n /**\n * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n * a default value of 18.\n *\n * To select a different value for {decimals}, use {_setupDecimals}.\n *\n * All three of these values are immutable: they can only be set once during\n * construction.\n */\n constructor(string memory name, string memory symbol) {\n _name = name;\n _symbol = symbol;\n _decimals = 18;\n }\n\n /**\n * @dev Returns the bep token owner.\n */\n function getOwner() external override view returns (address) {\n return owner();\n }\n\n /**\n * @dev Returns the name of the token.\n */\n function name() public override view returns (string memory) {\n return _name;\n }\n\n /**\n * @dev Returns the symbol of the token, usually a shorter version of the\n * name.\n */\n function symbol() public override view returns (string memory) {\n return _symbol;\n }\n\n /**\n * @dev Returns the number of decimals used to get its user representation.\n */\n function decimals() public override view returns (uint8) {\n return _decimals;\n }\n\n /**\n * @dev See {BEP20-totalSupply}.\n */\n function totalSupply() public override view returns (uint256) {\n return _totalSupply;\n }\n\n /**\n * @dev See {BEP20-balanceOf}.\n */\n function balanceOf(address account) public override view returns (uint256) {\n return _balances[account];\n }\n\n /**\n * @dev See {BEP20-transfer}.\n *\n * Requirements:\n *\n * - `recipient` cannot be the zero address.\n * - the caller must have a balance of at least `amount`.\n */\n function transfer(address recipient, uint256 amount) public override returns (bool) {\n _transfer(_msgSender(), recipient, amount);\n return true;\n }\n\n /**\n * @dev See {BEP20-allowance}.\n */\n function allowance(address owner, address spender) public override view returns (uint256) {\n return _allowances[owner][spender];\n }\n\n /**\n * @dev See {BEP20-approve}.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function approve(address spender, uint256 amount) public override returns (bool) {\n _approve(_msgSender(), spender, amount);\n return true;\n }\n\n /**\n * @dev See {BEP20-transferFrom}.\n *\n * Emits an {Approval} event indicating the updated allowance. This is not\n * required by the EIP. See the note at the beginning of {BEP20};\n *\n * Requirements:\n * - `sender` and `recipient` cannot be the zero address.\n * - `sender` must have a balance of at least `amount`.\n * - the caller must have allowance for `sender`'s tokens of at least\n * `amount`.\n */\n function transferFrom (address sender, address recipient, uint256 amount) public override returns (bool) {\n _transfer(sender, recipient, amount);\n _approve(\n sender,\n _msgSender(),\n _allowances[sender][_msgSender()].sub(amount, 'BEP20: transfer amount exceeds allowance')\n );\n return true;\n }\n\n /**\n * @dev Atomically increases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {BEP20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {\n _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n return true;\n }\n\n /**\n * @dev Atomically decreases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {BEP20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n * - `spender` must have allowance for the caller of at least\n * `subtractedValue`.\n */\n function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {\n _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, 'BEP20: decreased allowance below zero'));\n return true;\n }\n\n /**\n * @dev Creates `amount` tokens and assigns them to `msg.sender`, increasing\n * the total supply.\n *\n * Requirements\n *\n * - `msg.sender` must be the token owner\n */\n function mint(uint256 amount) external virtual onlyOwner returns (bool) {\n _mint(_msgSender(), amount);\n return true;\n }\n\n /**\n * @dev Moves tokens `amount` from `sender` to `recipient`.\n *\n * This is internal function is equivalent to {transfer}, and can be used to\n * e.g. implement automatic token fees, slashing mechanisms, etc.\n *\n * Emits a {Transfer} event.\n *\n * Requirements:\n *\n * - `sender` cannot be the zero address.\n * - `recipient` cannot be the zero address.\n * - `sender` must have a balance of at least `amount`.\n */\n function _transfer (address sender, address recipient, uint256 amount) internal virtual {\n require(sender != address(0), 'BEP20: transfer from the zero address');\n require(recipient != address(0), 'BEP20: transfer to the zero address');\n\n _balances[sender] = _balances[sender].sub(amount, 'BEP20: transfer amount exceeds balance');\n _balances[recipient] = _balances[recipient].add(amount);\n emit Transfer(sender, recipient, amount);\n }\n\n /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n * the total supply.\n *\n * Emits a {Transfer} event with `from` set to the zero address.\n *\n * Requirements\n *\n * - `to` cannot be the zero address.\n */\n function _mint(address account, uint256 amount) internal virtual {\n require(account != address(0), 'BEP20: mint to the zero address');\n\n _totalSupply = _totalSupply.add(amount);\n _balances[account] = _balances[account].add(amount);\n emit Transfer(address(0), account, amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`, reducing the\n * total supply.\n *\n * Emits a {Transfer} event with `to` set to the zero address.\n *\n * Requirements\n *\n * - `account` cannot be the zero address.\n * - `account` must have at least `amount` tokens.\n */\n function _burn(address account, uint256 amount) internal {\n require(account != address(0), 'BEP20: burn from the zero address');\n\n _balances[account] = _balances[account].sub(amount, 'BEP20: burn amount exceeds balance');\n _totalSupply = _totalSupply.sub(amount);\n emit Transfer(account, address(0), amount);\n }\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\n *\n * This is internal function is equivalent to `approve`, and can be used to\n * e.g. set automatic allowances for certain subsystems, etc.\n *\n * Emits an {Approval} event.\n *\n * Requirements:\n *\n * - `owner` cannot be the zero address.\n * - `spender` cannot be the zero address.\n */\n function _approve (address owner, address spender, uint256 amount) internal {\n require(owner != address(0), 'BEP20: approve from the zero address');\n require(spender != address(0), 'BEP20: approve to the zero address');\n\n _allowances[owner][spender] = amount;\n emit Approval(owner, spender, amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`.`amount` is then deducted\n * from the caller's allowance.\n *\n * See {_burn} and {_approve}.\n */\n function _burnFrom(address account, uint256 amount) internal {\n _burn(account, amount);\n _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, 'BEP20: burn amount exceeds allowance'));\n }\n}"
},
"@openzeppelin/contracts/access/Ownable.sol": {
"content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n address private _owner;\n\n event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n /**\n * @dev Initializes the contract setting the deployer as the initial owner.\n */\n constructor() {\n _setOwner(_msgSender());\n }\n\n /**\n * @dev Returns the address of the current owner.\n */\n function owner() public view virtual returns (address) {\n return _owner;\n }\n\n /**\n * @dev Throws if called by any account other than the owner.\n */\n modifier onlyOwner() {\n require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n _;\n }\n\n /**\n * @dev Leaves the contract without owner. It will not be possible to call\n * `onlyOwner` functions anymore. Can only be called by the current owner.\n *\n * NOTE: Renouncing ownership will leave the contract without an owner,\n * thereby removing any functionality that is only available to the owner.\n */\n function renounceOwnership() public virtual onlyOwner {\n _setOwner(address(0));\n }\n\n /**\n * @dev Transfers ownership of the contract to a new account (`newOwner`).\n * Can only be called by the current owner.\n */\n function transferOwnership(address newOwner) public virtual onlyOwner {\n require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n _setOwner(newOwner);\n }\n\n function _setOwner(address newOwner) private {\n address oldOwner = _owner;\n _owner = newOwner;\n emit OwnershipTransferred(oldOwner, newOwner);\n }\n}\n"
},
"@openzeppelin/contracts/utils/Context.sol": {
"content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n function _msgSender() internal view virtual returns (address) {\n return msg.sender;\n }\n\n function _msgData() internal view virtual returns (bytes calldata) {\n return msg.data;\n }\n}\n"
},
"contracts/libs/IBEP20.sol": {
"content": "// SPDX-License-Identifier: MIT\npragma solidity >=0.6.4;\n\ninterface IBEP20 {\n /**\n * @dev Returns the amount of tokens in existence.\n */\n function totalSupply() external view returns (uint256);\n\n /**\n * @dev Returns the token decimals.\n */\n function decimals() external view returns (uint8);\n\n /**\n * @dev Returns the token symbol.\n */\n function symbol() external view returns (string memory);\n\n /**\n * @dev Returns the token name.\n */\n function name() external view returns (string memory);\n\n /**\n * @dev Returns the bep token owner.\n */\n function getOwner() external view returns (address);\n\n /**\n * @dev Returns the amount of tokens owned by `account`.\n */\n function balanceOf(address account) external view returns (uint256);\n\n /**\n * @dev Moves `amount` tokens from the caller's account to `recipient`.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transfer(address recipient, uint256 amount) external returns (bool);\n\n /**\n * @dev Returns the remaining number of tokens that `spender` will be\n * allowed to spend on behalf of `owner` through {transferFrom}. This is\n * zero by default.\n *\n * This value changes when {approve} or {transferFrom} are called.\n */\n function allowance(address _owner, address spender) external view returns (uint256);\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * IMPORTANT: Beware that changing an allowance with this method brings the risk\n * that someone may use both the old and the new allowance by unfortunate\n * transaction ordering. One possible solution to mitigate this race\n * condition is to first reduce the spender's allowance to 0 and set the\n * desired value afterwards:\n * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n *\n * Emits an {Approval} event.\n */\n function approve(address spender, uint256 amount) external returns (bool);\n\n /**\n * @dev Moves `amount` tokens from `sender` to `recipient` using the\n * allowance mechanism. `amount` is then deducted from the caller's\n * allowance.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n /**\n * @dev Emitted when `value` tokens are moved from one account (`from`) to\n * another (`to`).\n *\n * Note that `value` may be zero.\n */\n event Transfer(address indexed from, address indexed to, uint256 value);\n\n /**\n * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n * a call to {approve}. `value` is the new allowance.\n */\n event Approval(address indexed owner, address indexed spender, uint256 value);\n}"
},
"@openzeppelin/contracts/utils/math/SafeMath.sol": {
"content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n// CAUTION\n// This version of SafeMath should only be used with Solidity 0.8 or later,\n// because it relies on the compiler's built in overflow checks.\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations.\n *\n * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler\n * now has built in overflow checking.\n */\nlibrary SafeMath {\n /**\n * @dev Returns the addition of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n uint256 c = a b;\n if (c < a) return (false, 0);\n return (true, c);\n }\n }\n\n /**\n * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b > a) return (false, 0);\n return (true, a - b);\n }\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n // benefit is lost if 'b' is also tested.\n // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n if (a == 0) return (true, 0);\n uint256 c = a * b;\n if (c / a != b) return (false, 0);\n return (true, c);\n }\n }\n\n /**\n * @dev Returns the division of two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b == 0) return (false, 0);\n return (true, a / b);\n }\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b == 0) return (false, 0);\n return (true, a % b);\n }\n }\n\n /**\n * @dev Returns the addition of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's ` ` operator.\n *\n * Requirements:\n *\n * - Addition cannot overflow.\n */\n function add(uint256 a, uint256 b) internal pure returns (uint256) {\n return a b;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting on\n * overflow (when the result is negative).\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n return a - b;\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's `*` operator.\n *\n * Requirements:\n *\n * - Multiplication cannot overflow.\n */\n function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n return a * b;\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting on\n * division by zero. The result is rounded towards zero.\n *\n * Counterpart to Solidity's `/` operator.\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(uint256 a, uint256 b) internal pure returns (uint256) {\n return a / b;\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting when dividing by zero.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n return a % b;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n * overflow (when the result is negative).\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {trySub}.\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b <= a, errorMessage);\n return a - b;\n }\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n * division by zero. The result is rounded towards zero.\n *\n * Counterpart to Solidity's `/` operator. Note: this function uses a\n * `revert` opcode (which leaves remaining gas untouched) while Solidity\n * uses an invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b > 0, errorMessage);\n return a / b;\n }\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting with custom message when dividing by zero.\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {tryMod}.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b > 0, errorMessage);\n return a % b;\n }\n }\n}\n"
}
},
"settings": {
"optimizer": {
"enabled": false,
"runs": 200
},
"outputSelection": {
"*": {
"*": [
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}}