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/** *Submitted for verification at BscScan.com on 2022-10-03*/// File: @openzeppelin/contracts@4.7.3/utils/Context.sol// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragma solidity ^0.8.0;/** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */abstract contract Context { function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; }}// File: @openzeppelin/contracts@4.7.3/token/ERC20/IERC20.sol// OpenZeppelin Contracts (last updated v4.6.0) (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);}// File: @openzeppelin/contracts@4.7.3/token/ERC20/extensions/IERC20Metadata.sol// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)pragma solidity ^0.8.0;/** * @dev Interface for the optional metadata functions from the ERC20 standard. * * _Available since v4.1._ */interface IERC20Metadata is IERC20 { /** * @dev Returns the name of the token. */ function name() external view returns (string memory); /** * @dev Returns the symbol of the token. */ function symbol() external view returns (string memory); /** * @dev Returns the decimals places of the token. */ function decimals() external view returns (uint8);}// File: @openzeppelin/contracts@4.7.3/token/ERC20/ERC20.sol// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol)pragma solidity ^0.8.0;/** * @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 {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin Contracts guidelines: functions revert * instead 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 Context, IERC20, IERC20Metadata { mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply; string private _name; string private _symbol; /** * @dev Sets the values for {name} and {symbol}. * * The default value of {decimals} is 18. To select a different value for * {decimals} you should overload it. * * All two of these values are immutable: they can only be set once during * construction. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; } /** * @dev Returns the name of the token. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view virtual override 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. This is the value {ERC20} uses, unless this function is * overridden; * * NOTE: 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 virtual override returns (uint8) { return 18; } /** * @dev See {IERC20-totalSupply}. */ function totalSupply() public view virtual override returns (uint256) { return _totalSupply; } /** * @dev See {IERC20-balanceOf}. */ function balanceOf(address account) public view virtual override returns (uint256) { return _balances[account]; } /** * @dev See {IERC20-transfer}. * * Requirements: * * - `to` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address to, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _transfer(owner, to, amount); return true; } /** * @dev See {IERC20-allowance}. */ function allowance(address owner, address spender) public view virtual override returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {IERC20-approve}. * * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on * `transferFrom`. This is semantically equivalent to an infinite approval. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _approve(owner, spender, amount); 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}. * * NOTE: Does not update the allowance if the current allowance * is the maximum `uint256`. * * Requirements: * * - `from` and `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. * - the caller must have allowance for ``from``'s tokens of at least * `amount`. */ function transferFrom( address from, address to, uint256 amount ) public virtual override returns (bool) { address spender = _msgSender(); _spendAllowance(from, spender, amount); _transfer(from, to, 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 virtual returns (bool) { address owner = _msgSender(); _approve(owner, spender, allowance(owner, spender) + 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 virtual returns (bool) { address owner = _msgSender(); uint256 currentAllowance = allowance(owner, spender); require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(owner, spender, currentAllowance - subtractedValue); } return true; } /** * @dev Moves `amount` of tokens from `from` to `to`. * * This 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: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. */ function _transfer( address from, address to, uint256 amount ) internal virtual { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(from, to, amount); uint256 fromBalance = _balances[from]; require(fromBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _balances[from] = fromBalance - amount; } _balances[to] += amount; emit Transfer(from, to, amount); _afterTokenTransfer(from, to, 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: * * - `account` cannot be the zero address. */ function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply += amount; _balances[account] += amount; emit Transfer(address(0), account, amount); _afterTokenTransfer(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 amount) internal virtual { require(account != address(0), "ERC20: burn from the zero address"); _beforeTokenTransfer(account, address(0), amount); uint256 accountBalance = _balances[account]; require(accountBalance >= amount, "ERC20: burn amount exceeds balance"); unchecked { _balances[account] = accountBalance - amount; } _totalSupply -= amount; emit Transfer(account, address(0), amount); _afterTokenTransfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. * * This 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 amount ) internal virtual { 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); } /** * @dev Updates `owner` s allowance for `spender` based on spent `amount`. * * Does not update the allowance amount in case of infinite allowance. * Revert if not enough allowance is available. * * Might emit an {Approval} event. */ function _spendAllowance( address owner, address spender, uint256 amount ) internal virtual { uint256 currentAllowance = allowance(owner, spender); if (currentAllowance != type(uint256).max) { require(currentAllowance >= amount, "ERC20: insufficient allowance"); unchecked { _approve(owner, spender, currentAllowance - amount); } } } /** * @dev Hook that is called before any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * will be transferred to `to`. * - when `from` is zero, `amount` tokens will be minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 amount ) internal virtual {} /** * @dev Hook that is called after any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * has been transferred to `to`. * - when `from` is zero, `amount` tokens have been minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens have been burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual {}}// File: @openzeppelin/contracts@4.7.3/token/ERC20/extensions/ERC20Burnable.sol// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol)pragma solidity ^0.8.0;/** * @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). */abstract contract ERC20Burnable is Context, ERC20 { /** * @dev Destroys `amount` tokens from the caller. * * See {ERC20-_burn}. */ function burn(uint256 amount) public virtual { _burn(_msgSender(), amount); } /** * @dev Destroys `amount` tokens from `account`, deducting from the caller's * allowance. * * See {ERC20-_burn} and {ERC20-allowance}. * * Requirements: * * - the caller must have allowance for ``accounts``'s tokens of at least * `amount`. */ function burnFrom(address account, uint256 amount) public virtual { _spendAllowance(account, _msgSender(), amount); _burn(account, amount); }}// File: contract-c3a8dbb83c.solpragma solidity ^0.8.4;/// @custom:security-contact dev@gameguru.ggcontract GameGuru is ERC20, ERC20Burnable { constructor() ERC20("GameGuru", "GGT") { _mint(msg.sender, 100000000 * 10 ** decimals()); }}
/**
*Submitted for verification at BscScan.com on 2022-10-03
*/
// File: @openzeppelin/contracts@4.7.3/utils/Context.sol
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
// File: @openzeppelin/contracts@4.7.3/token/ERC20/IERC20.sol
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
* @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.
* 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.
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
// File: @openzeppelin/contracts@4.7.3/token/ERC20/extensions/IERC20Metadata.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
* @dev Interface for the optional metadata functions from the ERC20 standard.
* _Available since v4.1._
interface IERC20Metadata is IERC20 {
* @dev Returns the name of the token.
function name() external view returns (string memory);
* @dev Returns the symbol of the token.
function symbol() external view returns (string memory);
* @dev Returns the decimals places of the token.
function decimals() external view returns (uint8);
// File: @openzeppelin/contracts@4.7.3/token/ERC20/ERC20.sol
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.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 {ERC20PresetMinterPauser}.
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead 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 Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
* @dev Sets the values for {name} and {symbol}.
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
* All two of these values are immutable: they can only be set once during
* construction.
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
function name() public view virtual override returns (string memory) {
return _name;
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
function symbol() public view virtual override 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. This is the value {ERC20} uses, unless this function is
* overridden;
* NOTE: 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 virtual override returns (uint8) {
return 18;
* @dev See {IERC20-totalSupply}.
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
* @dev See {IERC20-balanceOf}.
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
* @dev See {IERC20-transfer}.
* Requirements:
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
* @dev See {IERC20-allowance}.
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
* @dev See {IERC20-approve}.
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
* - `spender` cannot be the zero address.
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(owner, spender, amount);
* @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}.
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
* @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.
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(owner, spender, allowance(owner, spender) + addedValue);
* @dev Atomically decreases the allowance granted to `spender` by the caller.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
* @dev Moves `amount` of tokens from `from` to `to`.
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
* - `from` cannot be the zero address.
function _transfer(
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
_balances[from] = fromBalance - amount;
_balances[to] += amount;
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, 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.
* - `account` cannot be the zero address.
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(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.
* - `account` must have at least `amount` tokens.
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
_balances[account] = accountBalance - amount;
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
* - `owner` cannot be the zero address.
function _approve(
address owner,
address spender,
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);
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
* Might emit an {Approval} event.
function _spendAllowance(
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
_approve(owner, spender, currentAllowance - amount);
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
* Calling conditions:
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
function _beforeTokenTransfer(
) internal virtual {}
* @dev Hook that is called after any transfer of tokens. This includes
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
function _afterTokenTransfer(
// File: @openzeppelin/contracts@4.7.3/token/ERC20/extensions/ERC20Burnable.sol
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.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).
abstract contract ERC20Burnable is Context, ERC20 {
* @dev Destroys `amount` tokens from the caller.
* See {ERC20-_burn}.
function burn(uint256 amount) public virtual {
_burn(_msgSender(), amount);
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* See {ERC20-_burn} and {ERC20-allowance}.
* - the caller must have allowance for ``accounts``'s tokens of at least
function burnFrom(address account, uint256 amount) public virtual {
_spendAllowance(account, _msgSender(), amount);
_burn(account, amount);
// File: contract-c3a8dbb83c.sol
pragma solidity ^0.8.4;
/// @custom:security-contact dev@gameguru.gg
contract GameGuru is ERC20, ERC20Burnable {
constructor() ERC20("GameGuru", "GGT") {
_mint(msg.sender, 100000000 * 10 ** decimals());
The GameGuru smart contract is an implementation of an ERC-20 token on the Ethereum blockchain. Developed using the OpenZeppelin library, it provides standard token functionalities such as transfers, allowances, and balance queries. Additionally, the contract extends the ERC-20 standard by incorporating the ability to burn tokens. Upon deployment, the contract mints an initial supply of 100 million GameGuru tokens with the symbol "GGT."
This deployment is intended for use within the GameGuru ecosystem, offering flexibility for token holders to destroy their own tokens or those they have an allowance for, with such actions being recognizable off-chain through event analysis. The contract is designed to adhere to security best practices and has been submitted for verification on BscScan.
The provided code does not explicitly define privileged roles or access control mechanisms. In Ethereum smart contracts, privileged roles are often associated with certain capabilities, such as minting new tokens, burning tokens, and altering contract parameters.In this contract:
Minting Tokens: The `_mint` function is used in the constructor to mint an initial supply of tokens. This function is typically restricted to certain roles to prevent unauthorized minting after deployment.Burning Tokens: The `burn` and `burnFrom` functions allow token holders to burn their own tokens or tokens from another account, respectively. These functionalities are often open to any token holder.Constructor: The constructor is only executed once during deployment and mints tokens to the deployer's address.It's important to note that without explicit access control mechanisms, such as the use of modifiers or access control lists (ACLs), all functions are publicly accessible. If you intend to deploy this contract in a production environment, you may want to implement access control mechanisms to restrict certain functions to specific addresses or roles. This helps enhance the security of the contract and prevents unauthorized access to critical functions.
function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply += amount; _balances[account] += amount; emit Transfer(address(0), account, amount); _afterTokenTransfer(address(0), account, amount); }
Location in code: Inside the `_mint` functionLine number: 755-772Description: The `_mint` function is not protected by access control, allowing anyone to mint new tokens. Consider adding access control to restrict minting privileges to authorized roles.
function burn(uint256 amount) public virtual { _burn(_msgSender(), amount); }
Location in code: Inside the `burn` functionLine number: 1031-1035Description: The `burn` function does not incorporate access control, enabling any token holder to burn their own tokens. Consider implementing access control mechanisms to restrict burning capabilities.
function burnFrom(address account, uint256 amount) public virtual { _spendAllowance(account, _msgSender(), amount); _burn(account, amount); }
Location in code: Inside the burnFrom functionLine number: 1060-1066Description: The burnFrom function allows any caller to burn tokens from another account. Consider adding access controls to restrict this functionality to specific roles.
function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual {}
Location in code: Inside the _afterTokenTransfer functionLine number: 984-992Description: The _afterTokenTransfer function emits a Transfer event without validating the event parameters. While not a critical issue, it is good practice to validate event parameters to ensure data consistency.
constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; }
Location in code: Inside the constructor Line number: 367-373Description: The constructor that mints initial tokens should be restricted to specific roles to prevent unauthorized minting in a live environment.
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