pragma solidity ^0.5.9;
library SafeMath {
function add(uint a, uint b) internal pure returns (uint) {
uint c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint a, uint b) internal pure returns (uint) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
require(b <= a, errorMessage);
uint c = a - b;
return c;
}
function mul(uint a, uint b) internal pure returns (uint) {
if (a == 0) {
return 0;
}
uint c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint a, uint b) internal pure returns (uint) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint c = a / b;
return c;
}
}
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.
*
* 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.
*/
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.
*
* _Available since v2.4.0._
*/
function toPayable(address account) internal pure returns (address payable) {
return address(uint160(account));
}
/**
* @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].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-call-value
(bool success,) = recipient.call.value(amount)("");
require(success, "Address: unable to send value, recipient may have reverted");
}
}
interface IERC20 {
function totalSupply() external view returns (uint);
function balanceOf(address account) external view returns (uint);
function transfer(address recipient, uint amount) external returns (bool);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint amount) external returns (bool);
function transferFrom(address sender, address recipient, uint amount) external returns (bool);
event Transfer(address indexed from, address indexed to, uint value);
event Approval(address indexed owner, address indexed spender, uint value);
}
contract Context {
constructor () internal {}
// solhint-disable-previous-line no-empty-blocks
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
}
contract ERC20 is Context, IERC20 {
using SafeMath for uint;
mapping(address => uint) private _balances;
mapping(address => mapping(address => uint)) private _allowances;
uint private _totalSupply;
function totalSupply() public view returns (uint) {
return _totalSupply;
}
function balanceOf(address account) public view returns (uint) {
return _balances[account];
}
function transfer(address recipient, uint amount) public returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function allowance(address owner, address spender) public view returns (uint) {
return _allowances[owner][spender];
}
function approve(address spender, uint amount) public returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint amount) public returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function increaseAllowance(address spender, uint addedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
function decreaseAllowance(address spender, uint subtractedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
function _transfer(address sender, address recipient, uint 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, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
function _mint(address account, uint 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);
}
function _burn(address account, uint amount) internal {
require(account != address(0), "ERC20: burn from the zero address");
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
function _approve(address owner, address spender, uint amount) internal {
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);
}
}
contract ERC20Detailed is IERC20 {
string private _name;
string private _symbol;
uint8 private _decimals;
constructor (string memory name, string memory symbol, uint8 decimals) public {
_name = name;
_symbol = symbol;
_decimals = decimals;
}
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;
}
}
contract Token is ERC20, ERC20Detailed {
constructor () public ERC20Detailed("New year token", "NYT", 18) {
super._mint(msg.sender, 2021 ether);
}
}
{
"compilationTarget": {
"Token.sol": "Token"
},
"evmVersion": "petersburg",
"libraries": {},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}
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