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pragma solidity ^0.5.0; | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* This test is non-exhaustive, and there may be false-negatives: during the | |
* execution of a contract's constructor, its address will be reported as | |
* not containing a contract. | |
* | |
* > It is unsafe to assume that an address for which this function returns | |
* false is an externally-owned account (EOA) and not a contract. | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies in extcodesize, which returns 0 for contracts in | |
// construction, since the code is only stored at the end of the | |
// constructor execution. | |
// 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 != 0x0 && codehash != accountHash); | |
} | |
/** | |
* @dev Converts an `address` into `address payable`. Note that this is | |
* simply a type cast: the actual underlying value is not changed. | |
*/ | |
function toPayable(address account) internal pure returns (address payable) { | |
return address(uint160(account)); | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./IERC20.sol"; | |
import "../../math/SafeMath.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 `ERC20Mintable`. | |
* | |
* *For a detailed writeup see our guide [How to implement supply | |
* mechanisms](https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226).* | |
* | |
* We have followed general OpenZeppelin guidelines: functions revert instead | |
* of 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 IERC20 { | |
using SafeMath for uint256; | |
mapping (address => uint256) private _balances; | |
mapping (address => mapping (address => uint256)) private _allowances; | |
uint256 private _totalSupply; | |
/** | |
* @dev See `IERC20.totalSupply`. | |
*/ | |
function totalSupply() public view returns (uint256) { | |
return _totalSupply; | |
} | |
/** | |
* @dev See `IERC20.balanceOf`. | |
*/ | |
function balanceOf(address account) public view returns (uint256) { | |
return _balances[account]; | |
} | |
/** | |
* @dev See `IERC20.transfer`. | |
* | |
* Requirements: | |
* | |
* - `recipient` cannot be the zero address. | |
* - the caller must have a balance of at least `amount`. | |
*/ | |
function transfer(address recipient, uint256 amount) public returns (bool) { | |
_transfer(msg.sender, recipient, amount); | |
return true; | |
} | |
/** | |
* @dev See `IERC20.allowance`. | |
*/ | |
function allowance(address owner, address spender) public view returns (uint256) { | |
return _allowances[owner][spender]; | |
} | |
/** | |
* @dev See `IERC20.approve`. | |
* | |
* Requirements: | |
* | |
* - `spender` cannot be the zero address. | |
*/ | |
function approve(address spender, uint256 value) public returns (bool) { | |
_approve(msg.sender, spender, value); | |
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`; | |
* | |
* Requirements: | |
* - `sender` and `recipient` cannot be the zero address. | |
* - `sender` must have a balance of at least `value`. | |
* - the caller must have allowance for `sender`'s tokens of at least | |
* `amount`. | |
*/ | |
function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) { | |
_transfer(sender, recipient, amount); | |
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(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 returns (bool) { | |
_approve(msg.sender, spender, _allowances[msg.sender][spender].add(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 returns (bool) { | |
_approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue)); | |
return true; | |
} | |
/** | |
* @dev Moves tokens `amount` from `sender` to `recipient`. | |
* | |
* This is 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: | |
* | |
* - `sender` cannot be the zero address. | |
* - `recipient` cannot be the zero address. | |
* - `sender` must have a balance of at least `amount`. | |
*/ | |
function _transfer(address sender, address recipient, uint256 amount) internal { | |
require(sender != address(0), "ERC20: transfer from the zero address"); | |
require(recipient != address(0), "ERC20: transfer to the zero address"); | |
_balances[sender] = _balances[sender].sub(amount); | |
_balances[recipient] = _balances[recipient].add(amount); | |
emit Transfer(sender, recipient, 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 | |
* | |
* - `to` cannot be the zero address. | |
*/ | |
function _mint(address account, uint256 amount) internal { | |
require(account != address(0), "ERC20: mint to the zero address"); | |
_totalSupply = _totalSupply.add(amount); | |
_balances[account] = _balances[account].add(amount); | |
emit Transfer(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 value) internal { | |
require(account != address(0), "ERC20: burn from the zero address"); | |
_totalSupply = _totalSupply.sub(value); | |
_balances[account] = _balances[account].sub(value); | |
emit Transfer(account, address(0), value); | |
} | |
/** | |
* @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens. | |
* | |
* This is 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 value) internal { | |
require(owner != address(0), "ERC20: approve from the zero address"); | |
require(spender != address(0), "ERC20: approve to the zero address"); | |
_allowances[owner][spender] = value; | |
emit Approval(owner, spender, value); | |
} | |
/** | |
* @dev Destoys `amount` tokens from `account`.`amount` is then deducted | |
* from the caller's allowance. | |
* | |
* See `_burn` and `_approve`. | |
*/ | |
function _burnFrom(address account, uint256 amount) internal { | |
_burn(account, amount); | |
_approve(account, msg.sender, _allowances[account][msg.sender].sub(amount)); | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./ERC20.sol"; | |
/** | |
* @dev Extension of `ERC20` that allows token holders to destroy both their own | |
* tokens and those that they have an allowance for, in a way that can be | |
* recognized off-chain (via event analysis). | |
*/ | |
contract ERC20Burnable is ERC20 { | |
/** | |
* @dev Destroys `amount` tokens from the caller. | |
* | |
* See `ERC20._burn`. | |
*/ | |
function burn(uint256 amount) public { | |
_burn(msg.sender, amount); | |
} | |
/** | |
* @dev See `ERC20._burnFrom`. | |
*/ | |
function burnFrom(address account, uint256 amount) public { | |
_burnFrom(account, amount); | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./ERC20Mintable.sol"; | |
/** | |
* @dev Extension of `ERC20Mintable` that adds a cap to the supply of tokens. | |
*/ | |
contract ERC20Capped is ERC20Mintable { | |
uint256 private _cap; | |
/** | |
* @dev Sets the value of the `cap`. This value is immutable, it can only be | |
* set once during construction. | |
*/ | |
constructor (uint256 cap) public { | |
require(cap > 0, "ERC20Capped: cap is 0"); | |
_cap = cap; | |
} | |
/** | |
* @dev Returns the cap on the token's total supply. | |
*/ | |
function cap() public view returns (uint256) { | |
return _cap; | |
} | |
/** | |
* @dev See `ERC20Mintable.mint`. | |
* | |
* Requirements: | |
* | |
* - `value` must not cause the total supply to go over the cap. | |
*/ | |
function _mint(address account, uint256 value) internal { | |
require(totalSupply().add(value) <= _cap, "ERC20Capped: cap exceeded"); | |
super._mint(account, value); | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./IERC20.sol"; | |
/** | |
* @dev Optional functions from the ERC20 standard. | |
*/ | |
contract ERC20Detailed is IERC20 { | |
string private _name; | |
string private _symbol; | |
uint8 private _decimals; | |
/** | |
* @dev Sets the values for `name`, `symbol`, and `decimals`. All three of | |
* these values are immutable: they can only be set once during | |
* construction. | |
*/ | |
constructor (string memory name, string memory symbol, uint8 decimals) public { | |
_name = name; | |
_symbol = symbol; | |
_decimals = decimals; | |
} | |
/** | |
* @dev Returns the name of the token. | |
*/ | |
function name() public view returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev Returns the symbol of the token, usually a shorter version of the | |
* name. | |
*/ | |
function symbol() public view 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. | |
* | |
* > Note that 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 returns (uint8) { | |
return _decimals; | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./ERC20.sol"; | |
import "../../access/roles/MinterRole.sol"; | |
/** | |
* @dev Extension of `ERC20` that adds a set of accounts with the `MinterRole`, | |
* which have permission to mint (create) new tokens as they see fit. | |
* | |
* At construction, the deployer of the contract is the only minter. | |
*/ | |
contract ERC20Mintable is ERC20, MinterRole { | |
/** | |
* @dev See `ERC20._mint`. | |
* | |
* Requirements: | |
* | |
* - the caller must have the `MinterRole`. | |
*/ | |
function mint(address account, uint256 amount) public onlyMinter returns (bool) { | |
_mint(account, amount); | |
return true; | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./ERC20.sol"; | |
import "../../lifecycle/Pausable.sol"; | |
/** | |
* @title Pausable token | |
* @dev ERC20 with pausable transfers and allowances. | |
* | |
* Useful if you want to e.g. stop trades until the end of a crowdsale, or have | |
* an emergency switch for freezing all token transfers in the event of a large | |
* bug. | |
*/ | |
contract ERC20Pausable is ERC20, Pausable { | |
function transfer(address to, uint256 value) public whenNotPaused returns (bool) { | |
return super.transfer(to, value); | |
} | |
function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) { | |
return super.transferFrom(from, to, value); | |
} | |
function approve(address spender, uint256 value) public whenNotPaused returns (bool) { | |
return super.approve(spender, value); | |
} | |
function increaseAllowance(address spender, uint256 addedValue) public whenNotPaused returns (bool) { | |
return super.increaseAllowance(spender, addedValue); | |
} | |
function decreaseAllowance(address spender, uint256 subtractedValue) public whenNotPaused returns (bool) { | |
return super.decreaseAllowance(spender, subtractedValue); | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./ERC20.sol"; | |
import "./ERC20Detailed.sol"; | |
contract ExampleToken is ERC20, ERC20Detailed { | |
uint private INITIAL_SUPPLY = 300000000e6; | |
constructor () public ERC20Detailed("Hydra", "HDR", 6) { | |
_mint(msg.sender, INITIAL_SUPPLY); | |
} | |
} |
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pragma solidity ^0.5.0; | |
/** | |
* @dev Interface of the ERC20 standard as defined in the EIP. Does not include | |
* the optional functions; to access them see `ERC20Detailed`. | |
*/ | |
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. | |
* | |
* > 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); | |
} |
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pragma solidity ^0.5.0; | |
import "./IERC20.sol"; | |
import "./SafeMath.sol"; | |
import "./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 ERC20;` 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)); | |
} | |
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); | |
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. | |
// A Solidity high level call has three parts: | |
// 1. The target address is checked to verify it contains contract code | |
// 2. The call itself is made, and success asserted | |
// 3. The return value is decoded, which in turn checks the size of the returned data. | |
// solhint-disable-next-line max-line-length | |
require(address(token).isContract(), "SafeERC20: call to non-contract"); | |
// solhint-disable-next-line avoid-low-level-calls | |
(bool success, bytes memory returndata) = address(token).call(data); | |
require(success, "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"); | |
} | |
} | |
} |
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pragma solidity ^0.5.0; | |
/** | |
* @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, 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"); | |
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-solidity/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) { | |
// Solidity only automatically asserts when dividing by 0 | |
require(b > 0, "SafeMath: division by zero"); | |
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) { | |
require(b != 0, "SafeMath: modulo by zero"); | |
return a % b; | |
} | |
} |
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pragma solidity ^0.5.0; | |
import "./SafeERC20.sol"; | |
/** | |
* @dev A token holder contract that will allow a beneficiary to extract the | |
* tokens after a given release time. | |
* | |
* Useful for simple vesting schedules like "advisors get all of their tokens | |
* after 1 year". | |
* | |
* For a more complete vesting schedule, see | |
* [`TokenVesting`](api/drafts#tokenvesting). | |
*/ | |
contract TokenTimelock { | |
using SafeERC20 for IERC20; | |
// ERC20 basic token contract being held | |
IERC20 private _token; | |
// beneficiary of tokens after they are released | |
address private _beneficiary; | |
// timestamp when token release is enabled | |
uint256 private _releaseTime; | |
constructor (IERC20 token, address beneficiary, uint256 releaseTime) public { | |
// solhint-disable-next-line not-rely-on-time | |
require(releaseTime > block.timestamp, "TokenTimelock: release time is before current time"); | |
_token = token; | |
_beneficiary = beneficiary; | |
_releaseTime = releaseTime; | |
} | |
/** | |
* @return the token being held. | |
*/ | |
function token() public view returns (IERC20) { | |
return _token; | |
} | |
/** | |
* @return the beneficiary of the tokens. | |
*/ | |
function beneficiary() public view returns (address) { | |
return _beneficiary; | |
} | |
/** | |
* @return the time when the tokens are released. | |
*/ | |
function releaseTime() public view returns (uint256) { | |
return _releaseTime; | |
} | |
/** | |
* @notice Transfers tokens held by timelock to beneficiary. | |
*/ | |
function release() public { | |
// solhint-disable-next-line not-rely-on-time | |
require(block.timestamp >= _releaseTime, "TokenTimelock: current time is before release time"); | |
uint256 amount = _token.balanceOf(address(this)); | |
require(amount > 0, "TokenTimelock: no tokens to release"); | |
_token.safeTransfer(_beneficiary, amount); | |
} | |
} |
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