Contract Name:
NineInchPair
Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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: GPLv3
pragma solidity 0.8.19;
// a library for performing various math operations
library Math {
function min(uint x, uint y) internal pure returns (uint z) {
z = x < y ? x : y;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrt(uint y) internal pure returns (uint z) {
if (y > 3) {
z = y;
uint x = y / 2 + 1;
while (x < z) {
z = x;
x = (y / x + x) / 2;
}
} else if (y != 0) {
z = 1;
}
}
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @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) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @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 sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @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) {
// 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 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) {
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;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts 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 mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message 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,
string memory errorMessage
) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
function min(uint256 x, uint256 y) internal pure returns (uint256 z) {
z = x < y ? x : y;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrt(uint256 y) internal pure returns (uint256 z) {
if (y > 3) {
z = y;
uint256 x = y / 2 + 1;
while (x < z) {
z = x;
x = (y / x + x) / 2;
}
} else if (y != 0) {
z = 1;
}
}
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))
// range: [0, 2**112 - 1]
// resolution: 1 / 2**112
library UQ112x112 {
uint224 constant Q112 = 2 ** 112;
// encode a uint112 as a UQ112x112
function encode(uint112 y) internal pure returns (uint224 z) {
z = uint224(y) * Q112; // never overflows
}
// divide a UQ112x112 by a uint112, returning a UQ112x112
function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
z = x / uint224(y);
}
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
interface INineInchCallee {
function nineInchCallee(
address sender,
uint amount0,
uint amount1,
bytes calldata data
) external;
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
interface INineInchERC20 {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(
address owner,
address spender
) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(
address from,
address to,
uint value
) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(
address owner,
address spender,
uint value,
uint deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
interface INineInchFactory {
event PairCreated(
address indexed token0,
address indexed token1,
address pair,
uint
);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(
address tokenA,
address tokenB
) external view returns (address pair);
function allPairs(uint) external view returns (address pair);
function allPairsLength() external view returns (uint);
function createPair(
address tokenA,
address tokenB
) external returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
interface INineInchPair {
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(
address owner,
address spender
) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(
address from,
address to,
uint value
) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external view returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(
address owner,
address spender,
uint value,
uint deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(
address indexed sender,
uint amount0,
uint amount1,
address indexed to
);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves()
external
view
returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(
uint amount0Out,
uint amount1Out,
address to,
bytes calldata data
) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
import "./interfaces/INineInchERC20.sol";
import "../libraries/SafeMath.sol";
contract NineInchERC20 is INineInchERC20 {
using SafeMath for uint;
string public constant override name = unicode"🍆 9 LP";
string public constant override symbol = unicode"🍆 9 LP";
uint8 public constant override decimals = 18;
uint public totalSupply;
mapping(address => uint) public override balanceOf;
mapping(address => mapping(address => uint)) public override allowance;
bytes32 public override DOMAIN_SEPARATOR;
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
bytes32 public constant override PERMIT_TYPEHASH =
0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
mapping(address => uint) public override nonces;
constructor() {
uint chainId;
assembly {
chainId := chainid()
}
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256(
"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
),
keccak256(bytes(name)),
keccak256(bytes("1")),
chainId,
address(this)
)
);
}
function _mint(address to, uint value) internal {
totalSupply = totalSupply.add(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(address(0), to, value);
}
function _burn(address from, uint value) internal {
balanceOf[from] = balanceOf[from].sub(value);
totalSupply = totalSupply.sub(value);
emit Transfer(from, address(0), value);
}
function _approve(address owner, address spender, uint value) private {
allowance[owner][spender] = value;
emit Approval(owner, spender, value);
}
function _transfer(address from, address to, uint value) private {
balanceOf[from] = balanceOf[from].sub(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(from, to, value);
}
function approve(address spender, uint value) external returns (bool) {
_approve(msg.sender, spender, value);
return true;
}
function transfer(address to, uint value) external returns (bool) {
_transfer(msg.sender, to, value);
return true;
}
function transferFrom(
address from,
address to,
uint value
) external override returns (bool) {
if (allowance[from][msg.sender] != type(uint).max) {
allowance[from][msg.sender] = allowance[from][msg.sender].sub(
value
);
}
_transfer(from, to, value);
return true;
}
function permit(
address owner,
address spender,
uint value,
uint deadline,
uint8 v,
bytes32 r,
bytes32 s
) external {
require(deadline >= block.timestamp, "NineInch: EXPIRED");
bytes32 digest = keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR,
keccak256(
abi.encode(
PERMIT_TYPEHASH,
owner,
spender,
value,
nonces[owner]++,
deadline
)
)
)
);
address recoveredAddress = ecrecover(digest, v, r, s);
require(
recoveredAddress != address(0) && recoveredAddress == owner,
"NineInch: INVALID_SIGNATURE"
);
_approve(owner, spender, value);
}
}
// SPDX-License-Identifier: GPLv3
pragma solidity 0.8.19;
import "./interfaces/INineInchFactory.sol";
import "./interfaces/INineInchCallee.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./interfaces/INineInchERC20.sol";
import "./NineInchERC20.sol";
import "./interfaces/INineInchPair.sol";
import "../libraries/SafeMath.sol";
import "../libraries/UQ112x112.sol";
import "../libraries/Math.sol";
contract NineInchPair is NineInchERC20 {
using SafeMath for uint;
using UQ112x112 for uint224;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(
address indexed sender,
uint amount0,
uint amount1,
address indexed to
);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
uint public constant MINIMUM_LIQUIDITY = 10 ** 3;
bytes4 private constant SELECTOR =
bytes4(keccak256(bytes("transfer(address,uint256)")));
address public factory;
address public token0;
address public token1;
uint112 private reserve0; // uses single storage slot, accessible via getReserves
uint112 private reserve1; // uses single storage slot, accessible via getReserves
uint32 private blockTimestampLast; // uses single storage slot, accessible via getReserves
uint public price0CumulativeLast;
uint public price1CumulativeLast;
uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event
uint private unlocked = 1;
modifier lock() {
require(unlocked == 1, "NineInch: LOCKED");
unlocked = 0;
_;
unlocked = 1;
}
function getReserves()
public
view
returns (
uint112 _reserve0,
uint112 _reserve1,
uint32 _blockTimestampLast
)
{
_reserve0 = reserve0;
_reserve1 = reserve1;
_blockTimestampLast = blockTimestampLast;
}
function _safeTransfer(address token, address to, uint value) private {
(bool success, bytes memory data) = token.call(
abi.encodeWithSelector(SELECTOR, to, value)
);
require(
success && (data.length == 0 || abi.decode(data, (bool))),
"NineInch: TRANSFER_FAILED"
);
}
constructor() {
factory = msg.sender;
}
// called once by the factory at time of deployment
function initialize(address _token0, address _token1) external {
require(
_token0 != address(0) && _token1 != address(0),
"NineInch: ZERO_ADDRESS"
);
require(_token0 != _token1, "NineInch: IDENTICAL_ADDRESSES");
require(msg.sender == factory, "NineInch: FORBIDDEN"); // sufficient check
token0 = _token0;
token1 = _token1;
}
// update reserves and, on the first call per block, price accumulators
function _update(
uint balance0,
uint balance1,
uint112 _reserve0,
uint112 _reserve1
) private {
require(
balance0 <= type(uint112).max && balance1 <= type(uint112).max,
"NineInch: OVERFLOW"
);
uint32 blockTimestamp = uint32(block.timestamp % 2 ** 32);
uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
// * never overflows, and + overflow is desired
price0CumulativeLast +=
uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) *
timeElapsed;
price1CumulativeLast +=
uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) *
timeElapsed;
}
reserve0 = uint112(balance0);
reserve1 = uint112(balance1);
blockTimestampLast = blockTimestamp;
emit Sync(reserve0, reserve1);
}
// if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
function _mintFee(
uint112 _reserve0,
uint112 _reserve1
) private returns (bool feeOn) {
address feeTo = INineInchFactory(factory).feeTo();
feeOn = feeTo != address(0);
uint _kLast = kLast; // gas savings
if (feeOn) {
if (_kLast != 0) {
uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
uint rootKLast = Math.sqrt(_kLast);
if (rootK > rootKLast) {
uint numerator = totalSupply.mul(rootK.sub(rootKLast));
uint denominator = rootK.mul(7).add(rootKLast);
uint liquidity = numerator / denominator;
if (liquidity > 0) _mint(feeTo, liquidity);
}
}
} else if (_kLast != 0) {
kLast = 0;
}
}
// this low-level function should be called from a contract which performs important safety checks
function mint(address to) external lock returns (uint liquidity) {
(uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings
uint balance0 = IERC20(token0).balanceOf(address(this));
uint balance1 = IERC20(token1).balanceOf(address(this));
uint amount0 = balance0.sub(_reserve0);
uint amount1 = balance1.sub(_reserve1);
bool feeOn = _mintFee(_reserve0, _reserve1);
uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
if (_totalSupply == 0) {
liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
_mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
} else {
liquidity = Math.min(
amount0.mul(_totalSupply) / _reserve0,
amount1.mul(_totalSupply) / _reserve1
);
}
require(liquidity > 0, "NineInch: INSUFFICIENT_LIQUIDITY_MINTED");
_mint(to, liquidity);
_update(balance0, balance1, _reserve0, _reserve1);
if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
emit Mint(msg.sender, amount0, amount1);
}
// this low-level function should be called from a contract which performs important safety checks
function burn(
address to
) external lock returns (uint amount0, uint amount1) {
(uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings
address _token0 = token0; // gas savings
address _token1 = token1; // gas savings
uint balance0 = IERC20(_token0).balanceOf(address(this));
uint balance1 = IERC20(_token1).balanceOf(address(this));
uint liquidity = balanceOf[address(this)];
bool feeOn = _mintFee(_reserve0, _reserve1);
uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
require(
amount0 > 0 && amount1 > 0,
"NineInch: INSUFFICIENT_LIQUIDITY_BURNED"
);
_burn(address(this), liquidity);
_safeTransfer(_token0, to, amount0);
_safeTransfer(_token1, to, amount1);
balance0 = IERC20(_token0).balanceOf(address(this));
balance1 = IERC20(_token1).balanceOf(address(this));
_update(balance0, balance1, _reserve0, _reserve1);
if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
emit Burn(msg.sender, amount0, amount1, to);
}
// this low-level function should be called from a contract which performs important safety checks
function swap(
uint amount0Out,
uint amount1Out,
address to,
bytes calldata data
) external lock {
require(
amount0Out > 0 || amount1Out > 0,
"NineInch: INSUFFICIENT_OUTPUT_AMOUNT"
);
(uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings
require(
amount0Out < _reserve0 && amount1Out < _reserve1,
"NineInch: INSUFFICIENT_LIQUIDITY"
);
uint balance0;
uint balance1;
{
// scope for _token{0,1}, avoids stack too deep errors
address _token0 = token0;
address _token1 = token1;
require(to != _token0 && to != _token1, "NineInch: INVALID_TO");
if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
if (data.length > 0)
INineInchCallee(to).nineInchCallee(
msg.sender,
amount0Out,
amount1Out,
data
);
balance0 = IERC20(_token0).balanceOf(address(this));
balance1 = IERC20(_token1).balanceOf(address(this));
}
uint amount0In = balance0 > _reserve0 - amount0Out
? balance0 - (_reserve0 - amount0Out)
: 0;
uint amount1In = balance1 > _reserve1 - amount1Out
? balance1 - (_reserve1 - amount1Out)
: 0;
require(
amount0In > 0 || amount1In > 0,
"NineInch: INSUFFICIENT_INPUT_AMOUNT"
);
{
// scope for reserve{0,1}Adjusted, avoids stack too deep errors
uint balance0Adjusted = balance0.mul(10000).sub(amount0In.mul(29));
uint balance1Adjusted = balance1.mul(10000).sub(amount1In.mul(29));
require(
balance0Adjusted.mul(balance1Adjusted) >=
uint(_reserve0).mul(_reserve1).mul(10000 ** 2),
"NineInch: K"
);
}
_update(balance0, balance1, _reserve0, _reserve1);
emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
}
// force balances to match reserves
function skim(address to) external lock {
address _token0 = token0; // gas savings
address _token1 = token1; // gas savings
_safeTransfer(
_token0,
to,
IERC20(_token0).balanceOf(address(this)).sub(reserve0)
);
_safeTransfer(
_token1,
to,
IERC20(_token1).balanceOf(address(this)).sub(reserve1)
);
}
// force reserves to match balances
function sync() external lock {
_update(
IERC20(token0).balanceOf(address(this)),
IERC20(token1).balanceOf(address(this)),
reserve0,
reserve1
);
}
}