Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
import "./interfaces/MathUtil.sol";
import "./interfaces/ILockedCvx.sol";
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/token/ERC20/SafeERC20.sol';
import '@openzeppelin/contracts/math/SafeMath.sol';
interface IBasicRewards{
function getReward(address _account, bool _claimExtras) external;
function getReward(address _account) external;
function getReward(address _account, address _token) external;
function stakeFor(address, uint256) external;
}
interface ICvxRewards{
function getReward(address _account, bool _claimExtras, bool _stake) external;
}
interface IChefRewards{
function claim(uint256 _pid, address _account) external;
}
interface ICvxCrvDeposit{
function deposit(uint256, bool) external;
}
interface ISwapExchange {
function exchange(
int128,
int128,
uint256,
uint256
) external returns (uint256);
}
//Claim zap to bundle various reward claims
//v2:
// - change exchange to use curve pool
// - add getReward(address,token) type
// - add option to lock cvx
// - add option use all funds in wallet
contract ClaimZap{
using SafeERC20 for IERC20;
using SafeMath for uint256;
address public constant crv = address(0xD533a949740bb3306d119CC777fa900bA034cd52);
address public constant cvx = address(0x4e3FBD56CD56c3e72c1403e103b45Db9da5B9D2B);
address public constant cvxCrv = address(0x62B9c7356A2Dc64a1969e19C23e4f579F9810Aa7);
address public constant crvDeposit = address(0x8014595F2AB54cD7c604B00E9fb932176fDc86Ae);
address public constant cvxRewards = address(0xCF50b810E57Ac33B91dCF525C6ddd9881B139332);
address public constant exchange = address(0x9D0464996170c6B9e75eED71c68B99dDEDf279e8);//curve
address public constant locker = address(0x72a19342e8F1838460eBFCCEf09F6585e32db86E);
address public immutable cvxCrvRewards;
address public immutable owner;
enum Options{
ClaimCvx, //1
ClaimCvxAndStake, //2
ClaimCvxCrv, //4
ClaimLockedCvx, //8
ClaimLockedCvxStake, //16
LockCrvDeposit, //32
UseAllWalletFunds, //64
LockCvx //128
}
constructor(address _cvxcrvStaking) public {
owner = msg.sender;
cvxCrvRewards = _cvxcrvStaking;
}
//2.1 - change cvxcrv staking address as immutable in constructor, change claim parameters
function getName() external pure returns (string memory) {
return "ClaimZap V2.1";
}
function setApprovals() external {
require(msg.sender == owner, "!auth");
IERC20(crv).safeApprove(crvDeposit, 0);
IERC20(crv).safeApprove(crvDeposit, uint256(-1));
IERC20(crv).safeApprove(exchange, 0);
IERC20(crv).safeApprove(exchange, uint256(-1));
IERC20(cvx).safeApprove(cvxRewards, 0);
IERC20(cvx).safeApprove(cvxRewards, uint256(-1));
IERC20(cvxCrv).safeApprove(cvxCrvRewards, 0);
IERC20(cvxCrv).safeApprove(cvxCrvRewards, uint256(-1));
IERC20(cvx).safeApprove(locker, 0);
IERC20(cvx).safeApprove(locker, uint256(-1));
}
function CheckOption(uint256 _mask, uint256 _flag) internal pure returns(bool){
return (_mask & (1<<_flag)) != 0;
}
function claimRewards(
address[] calldata rewardContracts,
address[] calldata extraRewardContracts,
address[] calldata tokenRewardContracts,
address[] calldata tokenRewardTokens,
uint256 depositCrvMaxAmount,
uint256 minAmountOut,
uint256 depositCvxMaxAmount,
uint256 spendCvxAmount,
uint256 options
) external{
uint256 crvBalance = IERC20(crv).balanceOf(msg.sender);
uint256 cvxBalance = IERC20(cvx).balanceOf(msg.sender);
//claim from main curve LP pools
for(uint256 i = 0; i < rewardContracts.length; i++){
IBasicRewards(rewardContracts[i]).getReward(msg.sender,true);
}
//claim from extra rewards
for(uint256 i = 0; i < extraRewardContracts.length; i++){
IBasicRewards(extraRewardContracts[i]).getReward(msg.sender);
}
//claim from multi reward token contract
for(uint256 i = 0; i < tokenRewardContracts.length; i++){
IBasicRewards(tokenRewardContracts[i]).getReward(msg.sender,tokenRewardTokens[i]);
}
//claim others/deposit/lock/stake
_claimExtras(depositCrvMaxAmount,minAmountOut,depositCvxMaxAmount,spendCvxAmount,crvBalance,cvxBalance,options);
}
function _claimExtras(
uint256 depositCrvMaxAmount,
uint256 minAmountOut,
uint256 depositCvxMaxAmount,
uint256 spendCvxAmount,
uint256 removeCrvBalance,
uint256 removeCvxBalance,
uint256 options
) internal{
//claim (and stake) from cvx rewards
if(CheckOption(options,uint256(Options.ClaimCvxAndStake))){
ICvxRewards(cvxRewards).getReward(msg.sender,true,true);
}else if(CheckOption(options,uint256(Options.ClaimCvx))){
ICvxRewards(cvxRewards).getReward(msg.sender,true,false);
}
//claim from cvxCrv rewards
if(CheckOption(options,uint256(Options.ClaimCvxCrv))){
IBasicRewards(cvxCrvRewards).getReward(msg.sender);
}
//claim from locker
if(CheckOption(options,uint256(Options.ClaimLockedCvx))){
ILockedCvx(locker).getReward(msg.sender,CheckOption(options,uint256(Options.ClaimLockedCvxStake)));
}
//reset remove balances if we want to also stake/lock funds already in our wallet
if(CheckOption(options,uint256(Options.UseAllWalletFunds))){
removeCrvBalance = 0;
removeCvxBalance = 0;
}
//lock upto given amount of crv and stake
if(depositCrvMaxAmount > 0){
uint256 crvBalance = IERC20(crv).balanceOf(msg.sender).sub(removeCrvBalance);
crvBalance = MathUtil.min(crvBalance, depositCrvMaxAmount);
if(crvBalance > 0){
//pull crv
IERC20(crv).safeTransferFrom(msg.sender, address(this), crvBalance);
if(minAmountOut > 0){
//swap
ISwapExchange(exchange).exchange(0,1,crvBalance,minAmountOut);
}else{
//deposit
ICvxCrvDeposit(crvDeposit).deposit(crvBalance,CheckOption(options,uint256(Options.LockCrvDeposit)));
}
//get cvxcrv amount
uint256 cvxCrvBalance = IERC20(cvxCrv).balanceOf(address(this));
//stake for msg.sender
IBasicRewards(cvxCrvRewards).stakeFor(msg.sender, cvxCrvBalance);
}
}
//stake up to given amount of cvx
if(depositCvxMaxAmount > 0){
uint256 cvxBalance = IERC20(cvx).balanceOf(msg.sender).sub(removeCvxBalance);
cvxBalance = MathUtil.min(cvxBalance, depositCvxMaxAmount);
if(cvxBalance > 0){
//pull cvx
IERC20(cvx).safeTransferFrom(msg.sender, address(this), cvxBalance);
if(CheckOption(options,uint256(Options.LockCvx))){
ILockedCvx(locker).lock(msg.sender, cvxBalance, spendCvxAmount);
}else{
//stake for msg.sender
IBasicRewards(cvxRewards).stakeFor(msg.sender, cvxBalance);
}
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library MathUtil {
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;
interface ILockedCvx{
struct LockedBalance {
uint112 amount;
uint112 boosted;
uint32 unlockTime;
}
function lock(address _account, uint256 _amount, uint256 _spendRatio) external;
function processExpiredLocks(bool _relock) external;
function getReward(address _account, bool _stake) external;
function balanceAtEpochOf(uint256 _epoch, address _user) view external returns(uint256 amount);
function totalSupplyAtEpoch(uint256 _epoch) view external returns(uint256 supply);
function epochCount() external view returns(uint256);
function epochs(uint256 _id) external view returns(uint224,uint32);
function checkpointEpoch() external;
function balanceOf(address _account) external view returns(uint256);
function lockedBalanceOf(address _user) external view returns(uint256 amount);
function pendingLockOf(address _user) external view returns(uint256 amount);
function pendingLockAtEpochOf(uint256 _epoch, address _user) view external returns(uint256 amount);
function totalSupply() view external returns(uint256 supply);
function lockedBalances(
address _user
) view external returns(
uint256 total,
uint256 unlockable,
uint256 locked,
LockedBalance[] memory lockData
);
function addReward(
address _rewardsToken,
address _distributor,
bool _useBoost
) external;
function approveRewardDistributor(
address _rewardsToken,
address _distributor,
bool _approved
) external;
function setStakeLimits(uint256 _minimum, uint256 _maximum) external;
function setBoost(uint256 _max, uint256 _rate, address _receivingAddress) external;
function setKickIncentive(uint256 _rate, uint256 _delay) external;
function shutdown() external;
function recoverERC20(address _tokenAddress, uint256 _tokenAmount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 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://diligence.consensys.net/posts/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/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
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");
}
/**
* @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._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "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._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
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._
*/
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");
}
/**
* @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._
*/
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");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
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._
*/
function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
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._
*/
function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);
/**
* @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);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @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, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
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) {
// 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) {
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) {
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) {
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) {
require(b <= a, "SafeMath: subtraction overflow");
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) {
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, reverting 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) {
require(b > 0, "SafeMath: division by zero");
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) {
require(b > 0, "SafeMath: modulo by zero");
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) {
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.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* 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);
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) {
require(b > 0, errorMessage);
return a % b;
}
}