Contract Source Code:
/**
Website: ClownWorldPepe.com
Twitter: https://twitter.com/ClownWorldPepe_
Telegram: https://t.me/ClownWorldPepe
**/
pragma solidity 0.8.2;
// SPDX-License-Identifier: MIT
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
interface IUniswapV2Factory {
function createPair(address tokenA, address tokenB) external returns (address pair);
}
interface IUniswapV2Router {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidityETH(address token, uint amountTokenDesired, uint amountTokenMin, uint amountETHMin, address to, uint deadline) external payable returns (uint amountToken, uint amountETH, uint liquidity);
function swapExactTokensForETHSupportingFeeOnTransferTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external;
}
contract HONKLER is Ownable, ERC20 {
using SafeMath for uint256;
mapping (address => uint256) public _rOwned;
mapping (address => uint256) public _tOwned;
mapping (address => bool) public _isExcludedFromFee;
mapping (address => bool) public _isExcludedFromMaxTokenPerWallet;
mapping (address => bool) public _isExcludedFromReward;
mapping (address => bool) public _automatedMarketMakerPairs;
address[] private _excluded;
address public marketingWallet = payable(0xBf4A0c2325583C444307Fd81ADAa194B36A017De);
uint256 private constant MAX = ~uint256(0);
uint256 private constant _tTotal = 555555555555 * (10**18);
uint256 private _rTotal = (MAX - (MAX % _tTotal));
uint256 private _tFeeTotal;
uint256 public liquidityFeeTotal;
uint256 public marketingFeeTotal;
uint256[] public liquidityFee;
uint256[] public marketingFee;
uint256[] public reflectionFee;
uint256 private _liquidityFee;
uint256 private _marketingFee;
uint256 private _reflectionFee;
IUniswapV2Router public uniswapV2Router;
address public uniswapV2Pair;
bool private swapping;
bool public swapAndLiquifyEnabled;
uint256 public swapTokensAtAmount = 500000000 * (10**18);
uint256 public maxTokenPerWallet = 11111111110 * (10**18);
event SwapTokensAmountUpdated(uint256 amount);
event MarketingWalletUpdated(address newWallet);
event SwapAndLiquifyStatusUpdated(bool status);
event AutomatedMarketMakerPairUpdated(address pair, bool status);
event MigrateTokens(address token, address receiver, uint256 amount);
event TransferETH(address recipient, uint256 amount);
event LiquidityFeeUpdated(uint256 buy, uint256 sell, uint256 p2p);
event MarketingFeeUpdated(uint256 buy, uint256 sell, uint256 p2p);
event ReflectionFeeUpdated(uint256 buy, uint256 sell, uint256 p2p);
constructor (address owner) ERC20("Clown World Pepe", "$HONKLER") {
_rOwned[owner] = _rTotal;
uniswapV2Router = IUniswapV2Router(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
_setAutomatedMarketMakerPair(uniswapV2Pair, true);
_isExcludedFromFee[owner] = true;
_isExcludedFromFee[address(this)] = true;
_isExcludedFromMaxTokenPerWallet[address(uniswapV2Pair)] = true;
_isExcludedFromMaxTokenPerWallet[address(this)] = true;
_isExcludedFromMaxTokenPerWallet[owner] = true;
liquidityFee.push(100);
liquidityFee.push(100);
liquidityFee.push(0);
marketingFee.push(200);
marketingFee.push(200);
marketingFee.push(0);
reflectionFee.push(100);
reflectionFee.push(100);
reflectionFee.push(0);
_excludeFromReward(address(uniswapV2Pair));
_excludeFromReward(address(this));
swapAndLiquifyEnabled = true;
emit Transfer(address(0), owner, _tTotal);
}
receive() external payable {}
function totalSupply() public override pure returns (uint256) {
return _tTotal;
}
function excludeFromFee(address account, bool status) external onlyOwner {
require(_isExcludedFromFee[account] != status, "Account is already the value of 'status'");
_isExcludedFromFee[account] = status;
}
function excludeFromMaxTokenPerWallet(address account, bool status) external onlyOwner {
require(_isExcludedFromMaxTokenPerWallet[account] != status, "Account is already the value of 'status'");
_isExcludedFromMaxTokenPerWallet[account] = status;
}
function excludeFromReward(address account) public onlyOwner() {
require(!_isExcludedFromReward[account], "Account is already excluded");
if(_rOwned[account] > 0) {
_tOwned[account] = tokenFromReflection(_rOwned[account]);
}
_isExcludedFromReward[account] = true;
_excluded.push(account);
}
function includeInReward(address account) external onlyOwner() {
require(_isExcludedFromReward[account], "Account is already included");
for (uint256 i = 0; i < _excluded.length; i++) {
if (_excluded[i] == account) {
_excluded[i] = _excluded[_excluded.length - 1];
_tOwned[account] = 0;
_isExcludedFromReward[account] = false;
_excluded.pop();
break;
}
}
}
function setSwapTokensAtAmount(uint256 amount) external onlyOwner {
require(amount <= totalSupply(), "Amount cannot be over the total supply.");
swapTokensAtAmount = amount;
emit SwapTokensAmountUpdated(amount);
}
function setMarketingWallet(address payable _marketingWallet) external onlyOwner{
require(_marketingWallet != address(0), "Zero address");
marketingWallet = _marketingWallet;
emit MarketingWalletUpdated(_marketingWallet);
}
function setSwapAndLiquifyEnabled(bool status) external onlyOwner {
require(swapAndLiquifyEnabled != status, "Account is already the value of 'status'");
swapAndLiquifyEnabled = status;
emit SwapAndLiquifyStatusUpdated(status);
}
function setAutomatedMarketMakerPair(address pair, bool status) external onlyOwner {
require(_automatedMarketMakerPairs[pair] != status, "Automated market maker pair is already set to that value");
require(pair != address(uniswapV2Pair), "The pair cannot be removed from automatedMarketMakerPairs");
_automatedMarketMakerPairs[address(pair)] = status;
emit AutomatedMarketMakerPairUpdated(pair, status);
}
function setLiquidityFee(uint256 buy, uint256 sell, uint256 p2p) external onlyOwner {
require(marketingFee[0] + reflectionFee[0] + buy <= 600, "Max fee limit reached for 'BUY'");
require(marketingFee[1] + reflectionFee[1] + sell <= 600, "Max fee limit reached for 'SELL'");
require(marketingFee[2] + reflectionFee[2] + p2p <= 600, "Max fee limit reached for 'P2P'");
liquidityFee[0] = buy;
liquidityFee[1] = sell;
liquidityFee[2] = p2p;
emit LiquidityFeeUpdated(buy, sell, p2p);
}
function setMarketingFee(uint256 buy, uint256 sell, uint256 p2p) external onlyOwner {
require(liquidityFee[0] + reflectionFee[0] + buy <= 600, "Max fee limit reached for 'BUY'");
require(liquidityFee[1] + reflectionFee[1] + sell <= 600, "Max fee limit reached for 'SELL'");
require(liquidityFee[2] + reflectionFee[2] + p2p <= 600, "Max fee limit reached for 'P2P'");
marketingFee[0] = buy;
marketingFee[1] = sell;
marketingFee[2] = p2p;
emit MarketingFeeUpdated(buy, sell, p2p);
}
function setReflectionFee(uint256 buy, uint256 sell, uint256 p2p) external onlyOwner {
require(liquidityFee[0] + marketingFee[0] + buy <= 600, "Max fee limit reached for 'BUY'");
require(liquidityFee[1] + marketingFee[1] + sell <= 600, "Max fee limit reached for 'SELL'");
require(liquidityFee[2] + marketingFee[2] + p2p <= 600, "Max fee limit reached for 'P2P'");
reflectionFee[0] = buy;
reflectionFee[1] = sell;
reflectionFee[2] = p2p;
emit ReflectionFeeUpdated(buy, sell, p2p);
}
function balanceOf(address account) public override view returns (uint256) {
if (_isExcludedFromReward[account]) return _tOwned[account];
return tokenFromReflection(_rOwned[account]);
}
function tokenFromReflection(uint256 rAmount) public view returns(uint256) {
require(rAmount <= _rTotal, "Amount must be less than total reflections");
uint256 currentRate = _getRate();
return rAmount.div(currentRate);
}
function _excludeFromReward(address account) internal {
if(_rOwned[account] > 0) {
_tOwned[account] = tokenFromReflection(_rOwned[account]);
}
_isExcludedFromReward[account] = true;
_excluded.push(account);
}
function _setAutomatedMarketMakerPair(address pair, bool value) private {
require(_automatedMarketMakerPairs[pair] != value, "Automated market maker pair is already set to that value");
_automatedMarketMakerPairs[pair] = value;
}
function _reflectFee(uint256 rFee, uint256 tFee) private {
_rTotal = _rTotal.sub(rFee);
_tFeeTotal = _tFeeTotal.add(tFee);
}
function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256, uint256) {
(uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing) = _getTValues(tAmount);
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, tLiquidity, tMarketing, _getRate());
return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tLiquidity, tMarketing);
}
function _getTValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256) {
uint256 tFee = calculateReflectionFee(tAmount);
uint256 tLiquidity = calculateLiquidityFee(tAmount);
uint256 tMarketing = calculateMarketingFee(tAmount);
uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity).sub(tMarketing);
return (tTransferAmount, tFee, tLiquidity, tMarketing);
}
function _getRValues(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing, uint256 currentRate) private pure returns (uint256, uint256, uint256) {
uint256 rAmount = tAmount.mul(currentRate);
uint256 rFee = tFee.mul(currentRate);
uint256 rLiquidity = tLiquidity.mul(currentRate);
uint256 rMarketing = tMarketing.mul(currentRate);
uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity).sub(rMarketing);
return (rAmount, rTransferAmount, rFee);
}
function _getRate() private view returns(uint256) {
(uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
return rSupply.div(tSupply);
}
function _getCurrentSupply() private view returns(uint256, uint256) {
uint256 rSupply = _rTotal;
uint256 tSupply = _tTotal;
for (uint256 i = 0; i < _excluded.length; i++) {
if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal);
rSupply = rSupply.sub(_rOwned[_excluded[i]]);
tSupply = tSupply.sub(_tOwned[_excluded[i]]);
}
if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal);
return (rSupply, tSupply);
}
function _takeLiquidity(uint256 tLiquidity) private {
uint256 currentRate = _getRate();
uint256 rLiquidity = tLiquidity.mul(currentRate);
_rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity);
if(_isExcludedFromReward[address(this)])
_tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity);
}
function _takeMarketing(uint256 tMarketing) private {
uint256 currentRate = _getRate();
uint256 rMarketing = tMarketing.mul(currentRate);
_rOwned[address(this)] = _rOwned[address(this)].add(rMarketing);
if(_isExcludedFromReward[address(this)])
_tOwned[address(this)] = _tOwned[address(this)].add(tMarketing);
}
function calculateReflectionFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_reflectionFee).div(10000);
}
function calculateMarketingFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_marketingFee).div(10000);
}
function calculateLiquidityFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_liquidityFee).div(10000);
}
function removeAllFee() private {
_reflectionFee = 0;
_marketingFee = 0;
_liquidityFee = 0;
}
function applyBuyFee() private {
_reflectionFee = reflectionFee[0];
_marketingFee = marketingFee[0];
_liquidityFee = liquidityFee[0];
}
function applySellFee() private {
_reflectionFee = reflectionFee[1];
_marketingFee = marketingFee[1];
_liquidityFee = liquidityFee[1];
}
function applyP2PFee() private {
_reflectionFee = reflectionFee[2];
_marketingFee = marketingFee[2];
_liquidityFee = liquidityFee[2];
}
function _transfer(address from, address to, uint256 amount) internal override{
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
if(!_isExcludedFromMaxTokenPerWallet[to])
{
uint256 balanceRecepient = balanceOf(to);
require(balanceRecepient + amount <= maxTokenPerWallet, "Exceeds maximum token per wallet limit");
}
uint256 contractTokenBalance = balanceOf(address(this));
bool canSwap = contractTokenBalance >= swapTokensAtAmount;
if (canSwap && !swapping && _automatedMarketMakerPairs[to] && swapAndLiquifyEnabled)
{
uint256 tokenToLiqudity = liquidityFeeTotal.div(2);
uint256 tokenToMarketing = marketingFeeTotal;
uint256 tokenToSwap = tokenToLiqudity.add(tokenToMarketing);
if(tokenToSwap >= swapTokensAtAmount)
{
swapping = true;
uint256 initialBalance = address(this).balance;
swapTokensForETH(swapTokensAtAmount);
uint256 newBalance = address(this).balance.sub(initialBalance);
uint256 liqudityPart = newBalance.mul(tokenToLiqudity).div(tokenToSwap);
uint256 marketingPart = newBalance - liqudityPart;
if(liqudityPart > 0)
{
uint256 liqudityToken = swapTokensAtAmount.mul(tokenToLiqudity).div(tokenToSwap);
addLiquidity(liqudityToken, liqudityPart);
liquidityFeeTotal = liquidityFeeTotal.sub(liqudityToken).sub(liqudityToken);
}
if(marketingPart > 0)
{
payable(marketingWallet).transfer(marketingPart);
marketingFeeTotal = marketingFeeTotal.sub(swapTokensAtAmount.mul(tokenToMarketing).div(tokenToSwap));
}
swapping = false;
}
}
bool takeFee = true;
if(_isExcludedFromFee[from] || _isExcludedFromFee[to])
{
takeFee = false;
}
_tokenTransfer(from, to, amount, takeFee);
}
function _tokenTransfer(address sender, address recipient, uint256 amount, bool takeFee) private {
if(!takeFee)
{
removeAllFee();
}
else if(!_automatedMarketMakerPairs[sender] && !_automatedMarketMakerPairs[recipient])
{
applyP2PFee();
}
else if(_automatedMarketMakerPairs[recipient])
{
applySellFee();
}
else
{
applyBuyFee();
}
if (_isExcludedFromReward[sender] && !_isExcludedFromReward[recipient])
{
_transferFromExcluded(sender, recipient, amount);
}
else if (!_isExcludedFromReward[sender] && _isExcludedFromReward[recipient])
{
_transferToExcluded(sender, recipient, amount);
}
else if (!_isExcludedFromReward[sender] && !_isExcludedFromReward[recipient])
{
_transferStandard(sender, recipient, amount);
}
else if (_isExcludedFromReward[sender] && _isExcludedFromReward[recipient])
{
_transferBothExcluded(sender, recipient, amount);
}
else
{
_transferStandard(sender, recipient, amount);
}
}
function _transferStandard(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_takeMarketing(tMarketing);
_reflectFee(rFee, tFee);
liquidityFeeTotal += tLiquidity;
marketingFeeTotal += tMarketing;
if(tMarketing.add(tLiquidity) > 0)
{
emit Transfer(sender, address(this), tMarketing.add(tLiquidity));
}
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferToExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_takeMarketing(tMarketing);
_reflectFee(rFee, tFee);
liquidityFeeTotal += tLiquidity;
marketingFeeTotal += tMarketing;
if(tMarketing.add(tLiquidity) > 0)
{
emit Transfer(sender, address(this), tMarketing.add(tLiquidity));
}
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_takeMarketing(tMarketing);
_reflectFee(rFee, tFee);
liquidityFeeTotal += tLiquidity;
marketingFeeTotal += tMarketing;
if(tMarketing.add(tLiquidity) > 0)
{
emit Transfer(sender, address(this), tMarketing.add(tLiquidity));
}
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tMarketing) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_takeMarketing(tMarketing);
_reflectFee(rFee, tFee);
liquidityFeeTotal += tLiquidity;
marketingFeeTotal += tMarketing;
if(tMarketing.add(tLiquidity) > 0)
{
emit Transfer(sender, address(this), tMarketing.add(tLiquidity));
}
emit Transfer(sender, recipient, tTransferAmount);
}
function swapTokensForETH(uint256 tokenAmount) private {
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = uniswapV2Router.WETH();
_approve(address(this), address(uniswapV2Router), tokenAmount);
uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0,
path,
address(this),
block.timestamp
);
}
function addLiquidity(uint256 tokenAmount, uint256 ETHAmount) private{
_approve(address(this), address(uniswapV2Router), tokenAmount);
uniswapV2Router.addLiquidityETH{value: ETHAmount}(
address(this),
tokenAmount,
0,
0,
address(this),
block.timestamp
);
}
function migrateTokens(address token, address receiver, uint256 amount) external onlyOwner{
require(token != address(0), "Zero address");
require(receiver != address(0), "Zero address");
require(token != address(this), "Incorrect Token Address");
require(IERC20(token).balanceOf(address(this)) >= amount, "Insufficient balance on contract");
IERC20(token).transfer(address(receiver), amount);
emit MigrateTokens(token, receiver, amount);
}
function resetFee(address receiver) external onlyOwner{
liquidityFeeTotal = 0;
marketingFeeTotal = 0;
emit MigrateTokens(address(this), address(receiver), balanceOf(address(this)));
IERC20(address(this)).transfer(address(receiver), balanceOf(address(this)));
}
function migrateETH(address payable recipient) external onlyOwner{
require(recipient != address(0), "Zero address");
emit TransferETH(recipient, address(this).balance);
recipient.transfer(address(this).balance);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^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.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed 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.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
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) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)
pragma solidity ^0.8.0;
// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.
/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
return a + b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
return a * b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a / b;
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol)
pragma solidity ^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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* 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}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
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 value {ERC20} uses, unless this function is
* 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}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (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`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (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.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @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`.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @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.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @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`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @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(
address from,
address to,
uint256 amount
) internal virtual {
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;
}
_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) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_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) internal virtual {
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;
}
_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
) internal virtual {
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
) internal virtual {
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(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @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(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^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.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed 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.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (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.
*/
function transfer(address to, uint256 amount) external returns (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.
*/
function allowance(address owner, address spender) external view returns (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.
*/
function approve(address spender, uint256 amount) external returns (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.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}