// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)pragmasolidity ^0.8.1;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0// for contracts in construction, since the code is only stored at the end// of the constructor execution.return account.code.length>0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
(bool success, bytesmemory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
(bool success, bytesmemory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
(bool success, bytesmemory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/functionverifyCallResultFromTarget(address target,
bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
if (success) {
if (returndata.length==0) {
// only check isContract if the call was successful and the return data is empty// otherwise we already know that it was a contractrequire(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function_revert(bytesmemory returndata, stringmemory errorMessage) privatepure{
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly/// @solidity memory-safe-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
Contract Source Code
File 2 of 11: Cloakv2.sol
// SPDX-License-Identifier: MIT/*
▄████▄ ██▓ ▒█████ ▄▄▄ ██ ▄█▀
▒██▀ ▀█ ▓██▒ ▒██▒ ██▒▒████▄ ██▄█▒
▒▓█ ▄ ▒██░ ▒██░ ██▒▒██ ▀█▄ ▓███▄░
▒▓▓▄ ▄██▒▒██░ ▒██ ██░░██▄▄▄▄██ ▓██ █▄
▒ ▓███▀ ░░██████▒░ ████▓▒░ ▓█ ▓██▒▒██▒ █▄
░ ░▒ ▒ ░░ ▒░▓ ░░ ▒░▒░▒░ ▒▒ ▓▒█░▒ ▒▒ ▓▒
â–‘ â–’ â–‘ â–‘ â–’ â–‘ â–‘ â–’ â–’â–‘ â–’ â–’â–’ â–‘â–‘ â–‘â–’ â–’â–‘
â–‘ â–‘ â–‘ â–‘ â–‘ â–‘ â–’ â–‘ â–’ â–‘ â–‘â–‘ â–‘
â–‘ â–‘ â–‘ â–‘ â–‘ â–‘ â–‘ â–‘â–‘ â–‘
â–‘
The purpose-built Web3 GenAI engine for the privacy conscious individual or business.
Website: https://cloakai.xyz/
Litepaper: https://cloak-2.gitbook.io/cloak-docs
Twitter: https://twitter.com/Cloak_xyz
Telegram: https://t.me/cloakai
*/pragmasolidity ^0.8.0;import"@openzeppelin/contracts/utils/Address.sol";
import"@openzeppelin/contracts/token/ERC20/ERC20.sol";
import"@openzeppelin/contracts/access/Ownable.sol";
import"@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol";
import"@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol";
import"@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
contractCloakisERC20, Ownable{
usingAddressforaddress;
IUniswapV2Router02 publicimmutable uniswapRouter;
addresspublic uniswapPair;
addresspublic protocolWallet;
boolpublic tradingActive =false;
boolpublic swapEnabled =false;
boolpublic limitsInEffect =true;
uint256public maxTransaction;
uint256public swapTokensAtAmount;
uint256public maxWalletSize;
uint256public protocolBuyFee;
uint256public protocolSellFee;
uint256public tokensForProtocol;
boolprivate swapping;
mapping(address=>bool) private isBlackList;
mapping(address=>bool) public isExcludedFromFees;
mapping(address=>bool) public isExcludeMaxTransaction;
mapping(address=>bool) public ammPairs;
constructor() ERC20("Cloak", "CLOAK") {
uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
uniswapPair = IUniswapV2Factory(uniswapRouter.factory()).createPair(address(this), uniswapRouter.WETH());
protocolWallet =address(0x07DDBa2cc45970BBf81A79406DB9b19C68943F88);
isExcludeMaxTransaction[address(uniswapRouter)] =true;
isExcludeMaxTransaction[address(uniswapPair)] =true;
isExcludeMaxTransaction[owner()] =true;
isExcludeMaxTransaction[address(this)] =true;
isExcludeMaxTransaction[address(0xdead)] =true;
isExcludedFromFees[owner()] =true;
isExcludedFromFees[address(this)] =true;
isExcludedFromFees[address(0xdead)] =true;
ammPairs[address(uniswapPair)] =true;
uint256 totalSupply =100_000_000*1e18;
swapTokensAtAmount = (totalSupply *5) /10000; // 0.05% swap wallet
maxTransaction =1_300_000*1e18; // 1.3% from total supply maxTransactionTxn
maxWalletSize =1_300_000*1e18; // 1.3% from total supply maxWalletSize
protocolBuyFee =5;
protocolSellFee =5;
_mint(owner(), 41_101_699_010*1e15); // Remaining in liq pool
}
receive() externalpayable{}
// Claim new $CLOAK tokens, send old to protocol walletfunctionclaim(address claimer) external{
require(
IERC20(0xa62aF006902a53D03F819D0e0BE0609893EC3099).balanceOf(claimer) >0,
"No old CLOAK to exchange"
);
IERC20 oldCloak = IERC20(0xa62aF006902a53D03F819D0e0BE0609893EC3099);
uint256 amount = oldCloak.balanceOf(claimer);
oldCloak.transferFrom(claimer, address(protocolWallet), amount);
_mint(claimer, amount);
}
// Tansfer eth to protocolfunctiontransferEth(uint256 amount) externalonlyOwner{
require(amount >0, "Invalid amount of eth");
require(amount <=address(this).balance, "Not enough eth");
bool success;
(success, ) =address(protocolWallet).call{value: amount}("");
}
functionsetProtocolWallet(address protocolWallet_) externalonlyOwner{
protocolWallet = protocolWallet_;
}
functionopenTrading() externalonlyOwner{
tradingActive =true;
swapEnabled =true;
}
functionexcludeFromMaxTransaction(address addr, bool value) externalonlyOwner{
isExcludeMaxTransaction[addr] = value;
}
functionexcludeFromFees(address account, bool value) externalonlyOwner{
isExcludedFromFees[account] = value;
}
functionremoveLimits() externalonlyOwnerreturns (bool) {
limitsInEffect =false;
returntrue;
}
functionupdateSwapEnabled(bool enabled) externalonlyOwner{
swapEnabled = enabled;
}
functionupdateMaxWalletSize(uint256 newNum) externalonlyOwner{
require(newNum >= ((totalSupply() *5) /1000) /1e18, "Cannot set maxWalletSize lower than 0.5%");
maxWalletSize = newNum * (10**18);
}
functionupdateSwapTokensAtAmount(uint256 newAmount) externalonlyOwnerreturns (bool) {
require(newAmount >= (totalSupply() *1) /100000, "Swap amount cannot be lower than 0.001% total supply.");
require(newAmount <= (totalSupply() *5) /1000, "Swap amount cannot be higher than 0.5% total supply.");
swapTokensAtAmount = newAmount;
returntrue;
}
functionupdateMaxTransaction(uint256 newNum) externalonlyOwner{
require(newNum >= ((totalSupply() *1) /1000) /1e18, "Cannot set maxTransaction lower than 0.1%");
maxTransaction = newNum * (10**18);
}
functionupdateBuyFee(uint256 newBuyFee) externalonlyOwner{
require(newBuyFee <=25, "Must keep fees at 25% or less");
protocolBuyFee = newBuyFee;
}
functionupdateSellFee(uint256 newSellFee) externalonlyOwner{
require(newSellFee <=25, "Must keep fees at 25% or less");
protocolSellFee = newSellFee;
}
functionsetAMMPair(address pair, bool value) externalonlyOwner{
require(pair != uniswapPair, "The pair cannot be removed from ammPairs");
ammPairs[pair] = value;
}
functionsetBlackList(address addr, bool enable) externalonlyOwner{
isBlackList[addr] = enable;
}
functionswapBack() private{
uint256 contractBalance = balanceOf(address(this));
bool success;
if (contractBalance ==0) {
return;
}
if (contractBalance > swapTokensAtAmount *20) {
contractBalance = swapTokensAtAmount *20;
}
uint256 initialETHBalance =address(this).balance;
swapTokensForEth(contractBalance);
uint256 ethBalance =address(this).balance- initialETHBalance;
tokensForProtocol =0;
(success, ) =address(protocolWallet).call{value: ethBalance}("");
}
functionswapTokensForEth(uint256 tokenAmount) private{
// generate the uniswap pair path of token -> wethaddress[] memory path =newaddress[](2);
path[0] =address(this);
path[1] = uniswapRouter.WETH();
_approve(address(this), address(uniswapRouter), tokenAmount);
// make the swap
uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // accept any amount of ETH
path,
address(this),
block.timestamp
);
}
function_transfer(addressfrom, address to, uint256 amount) internaloverride{
require(from!=address(0), "ERC20: transfer from the zero address");
require(to !=address(0), "ERC20: transfer to the zero address");
require(!isBlackList[from], "[from] black list");
require(!isBlackList[to], "[to] black list");
if (amount ==0) {
super._transfer(from, to, 0);
return;
}
if (limitsInEffect) {
if (
from!= owner() &&
to != owner() &&
to !=address(0) &&
to !=address(0xdead) &&!swapping
) {
if (!tradingActive) {
require(isExcludedFromFees[from] || isExcludedFromFees[to], "Trading is not active.");
}
//when buyif (ammPairs[from] &&!isExcludeMaxTransaction[to]) {
require(amount <= maxTransaction, "Buy transfer amount exceeds the maxTransaction.");
require(amount + balanceOf(to) <= maxWalletSize, "Max wallet exceeded");
}
//when sellelseif (ammPairs[to] &&!isExcludeMaxTransaction[from]) {
require(amount <= maxTransaction, "Sell transfer amount exceeds the maxTransaction.");
}
elseif (!isExcludeMaxTransaction[to]) {
require(amount + balanceOf(to) <= maxWalletSize, "Max wallet exceeded");
}
}
}
uint256 contractBalance = balanceOf(address(this));
bool canSwap = contractBalance >= swapTokensAtAmount;
if (
canSwap &&
swapEnabled &&!swapping &&!ammPairs[from] &&!isExcludedFromFees[from] &&!isExcludedFromFees[to]
) {
swapping =true;
swapBack();
swapping =false;
}
bool takeFee =!swapping;
if (isExcludedFromFees[from] || isExcludedFromFees[to]) {
takeFee =false;
}
uint256 fee =0;
if (takeFee) {
// on sellif (ammPairs[to] && protocolSellFee >0) {
fee = amount * protocolSellFee /100;
tokensForProtocol += fee;
}
// on buyelseif (ammPairs[from] && protocolBuyFee >0) {
fee = amount * protocolBuyFee /100;
tokensForProtocol += fee;
}
if (fee >0) {
super._transfer(from, address(this), fee);
}
amount -= fee;
}
super._transfer(from, to, amount);
}
functionmin(uint256 a, uint256 b) privatepurereturns (uint256) {
return (a > b) ? b : a;
}
}
Contract Source Code
File 3 of 11: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)pragmasolidity ^0.8.0;/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
function_contextSuffixLength() internalviewvirtualreturns (uint256) {
return0;
}
}
Contract Source Code
File 4 of 11: ERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)pragmasolidity ^0.8.0;import"./IERC20.sol";
import"./extensions/IERC20Metadata.sol";
import"../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/contractERC20isContext, IERC20, IERC20Metadata{
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowances;
uint256private _totalSupply;
stringprivate _name;
stringprivate _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev 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 default value returned by this function, unless
* it's overridden.
*
* 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}.
*/functiondecimals() publicviewvirtualoverridereturns (uint8) {
return18;
}
/**
* @dev See {IERC20-totalSupply}.
*/functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/functionbalanceOf(address account) publicviewvirtualoverridereturns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/functiontransfer(address to, uint256 amount) publicvirtualoverridereturns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
returntrue;
}
/**
* @dev See {IERC20-allowance}.
*/functionallowance(address owner, address spender) publicviewvirtualoverridereturns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/functionapprove(address spender, uint256 amount) publicvirtualoverridereturns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
returntrue;
}
/**
* @dev 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}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/functiontransferFrom(addressfrom, address to, uint256 amount) publicvirtualoverridereturns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
returntrue;
}
/**
* @dev 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.
*/functionincreaseAllowance(address spender, uint256 addedValue) publicvirtualreturns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
returntrue;
}
/**
* @dev 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`.
*/functiondecreaseAllowance(address spender, uint256 subtractedValue) publicvirtualreturns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
returntrue;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/function_transfer(addressfrom, address to, uint256 amount) internalvirtual{
require(from!=address(0), "ERC20: transfer from the zero address");
require(to !=address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/function_mint(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/function_burn(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/function_approve(address owner, address spender, uint256 amount) internalvirtual{
require(owner !=address(0), "ERC20: approve from the zero address");
require(spender !=address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/function_spendAllowance(address owner, address spender, uint256 amount) internalvirtual{
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance !=type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/function_beforeTokenTransfer(addressfrom, address to, uint256 amount) internalvirtual{}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/function_afterTokenTransfer(addressfrom, address to, uint256 amount) internalvirtual{}
}
Contract Source Code
File 5 of 11: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransfer(address to, uint256 amount) externalreturns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/functionallowance(address owner, address spender) externalviewreturns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/functionapprove(address spender, uint256 amount) externalreturns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransferFrom(addressfrom, address to, uint256 amount) externalreturns (bool);
}
Contract Source Code
File 6 of 11: IERC20Metadata.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/interfaceIERC20MetadataisIERC20{
/**
* @dev Returns the name of the token.
*/functionname() externalviewreturns (stringmemory);
/**
* @dev Returns the symbol of the token.
*/functionsymbol() externalviewreturns (stringmemory);
/**
* @dev Returns the decimals places of the token.
*/functiondecimals() externalviewreturns (uint8);
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)pragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/function_checkOwner() internalviewvirtual{
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
require(newOwner !=address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/function_transferOwnership(address newOwner) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}