Secureum Race 4
Author: Rajeev from Secureum
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Secureum Race 4Author: Rajeev from Secureum
pragma solidity 0.8.10;
import "@openzeppelin/.../token/ERC20/IERC20.sol";
import "@openzeppelin/.../token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/.../utils/Context.sol";
contract InSecureum is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
function name() public view virtual override returns (string memory) {
return _name;
}
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
function decimals() public view virtual override returns (uint8) {
return 8;
}
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
function balanceOf(address account)
public
view
virtual
override
returns (uint256)
{
return _balances[account];
}
function transfer(address recipient, uint256 amount)
public
virtual
override
returns (bool)
{
_transfer(_msgSender(), recipient, amount);
return true;
}
function allowance(address owner, address spender)
public
view
virtual
override
returns (uint256)
{
return _allowances[owner][spender];
}
function approve(address spender, uint256 amount)
public
virtual
override
returns (bool)
{
_approve(_msgSender(), spender, amount);
return true;
}
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][sender];
if (currentAllowance != type(uint256).max) {
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
}
_transfer(sender, recipient, amount);
return true;
}
function increaseAllowance(address spender, uint256 addedValue)
public
virtual
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender] + addedValue
);
return true;
}
function decreaseAllowance(address spender, uint256 subtractedValue)
public
virtual
returns (bool)
{
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(
currentAllowance > subtractedValue,
"ERC20: decreased allowance below zero"
);
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
return true;
}
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
uint256 senderBalance = _balances[sender];
require(
senderBalance >= amount,
"ERC20: transfer amount exceeds balance"
);
unchecked {
_balances[sender] = senderBalance - amount;
}
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
}
function _mint(address account, uint256 amount) external virtual {
_totalSupply += amount;
_balances[account] = amount;
emit Transfer(address(0), account, amount);
}
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
require(
_balances[account] >= amount,
"ERC20: burn amount exceeds balance"
);
unchecked {
_balances[account] = _balances[account] - amount;
}
_totalSupply -= amount;
emit Transfer(address(0), account, amount);
}
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(spender != address(0), "ERC20: approve from the zero address");
require(owner != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] += amount;
emit Approval(owner, spender, amount);
}
}