Hi,
According to the solidity Style Guide, functions should be grouped according to their visibility and ordered as follows,
- constructor
- receive function (if exists)
- fallback function (if exists)
- external
- public
- internal
- private
within a grouping, place the view and pure functions last.
Yes:
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
contract A {
constructor() {
// ...
}
receive() external payable {
// ...
}
fallback() external {
// ...
}
// External functions
// ...
// External functions that are view
// ...
// External functions that are pure
// ...
// Public functions
// ...
// Internal functions
// ...
// Private functions
// ...
}
No:
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
contract A {
// External functions
// ...
fallback() external {
// ...
}
receive() external payable {
// ...
}
// Private functions
// ...
// Public functions
// ...
constructor() {
// ...
}
// Internal functions
// ...
}
So, I tried to follow these rules on "contract CuriosityToken". But now I am afraid of deploying it because I couldn't find any existing contract, which follows these rules.
Can somebody please advise me on this and have a look at the below code if you have time?.
Full code:
// SPDX-License-Identifier: Unlicensed
pragma solidity 0.8.9;
interface IBEP20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external pure returns (uint256);
/**
* @dev Returns the token decimals.
*/
function decimals() external pure returns (uint8);
/**
* @dev Returns the token symbol.
*/
function symbol() external pure returns (string memory);
/**
* @dev Returns the token name.
*/
function name() external pure returns (string memory);
/**
* @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 afterward:
* 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);
}
/**
* @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) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with
* custom message on overflow (when the result is negative).
*
* 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);
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-contracts/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) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with
* custom message 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,
string memory errorMessage
) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
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) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned
* integer modulo), Reverts with a custom message 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,
string memory errorMessage
) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
/**
* @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) {
// 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 != accountHash && codehash != 0x0);
}
/**
* @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 a BNB 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");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(
address target,
bytes memory data,
uint256 weiValue,
string memory errorMessage
) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
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);
}
}
}
}
/**
* @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).
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return payable (msg.sender);
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode
//- see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange, the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
/**
* @dev Contract module, which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without an owner. It will not be possible to call
* `onlyOwner` functions anymore. It can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() external virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) external virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
/**
* @dev Default configuration set for the PancakeSwap finance. PancakeSwap is a
* leading decentralized exchange on the Binance Smart Chain.
* Please refer to the below link for further details.
* https://docs.pancakeswap.finance/code/smart-contracts/pancakeswap-exchange
*
* WETH returns the canonical address for the WBNB token (ETH = BNB).
*/
interface IPancakeFactory {
event PairCreated(
address indexed token0,
address indexed token1,
address pair,
uint256
);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(address tokenA, address tokenB)
external
view
returns (address pair);
function allPairs(uint256) external view returns (address pair);
function allPairsLength() external view returns (uint256);
function createPair(address tokenA, address tokenB)
external
returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}
interface IPancakePair {
event Approval(
address indexed owner,
address indexed spender,
uint256 value
);
event Transfer(address indexed from, address indexed to, uint256 value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint256);
function balanceOf(address owner) external view returns (uint256);
function allowance(address owner, address spender)
external
view
returns (uint256);
function approve(address spender, uint256 value) external returns (bool);
function transfer(address to, uint256 value) external returns (bool);
function transferFrom(
address from,
address to,
uint256 value
) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint256);
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
event Mint(address indexed sender, uint256 amount0, uint256 amount1);
event Burn(
address indexed sender,
uint256 amount0,
uint256 amount1,
address indexed to
);
event Swap(
address indexed sender,
uint256 amount0In,
uint256 amount1In,
uint256 amount0Out,
uint256 amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint256);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves()
external
view
returns (
uint112 reserve0,
uint112 reserve1,
uint32 blockTimestampLast
);
function price0CumulativeLast() external view returns (uint256);
function price1CumulativeLast() external view returns (uint256);
function kLast() external view returns (uint256);
function mint(address to) external returns (uint256 liquidity);
function burn(address to)
external
returns (uint256 amount0, uint256 amount1);
function swap(
uint256 amount0Out,
uint256 amount1Out,
address to,
bytes calldata data
) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IPancakeRouter01 {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidity(
address tokenA,
address tokenB,
uint256 amountADesired,
uint256 amountBDesired,
uint256 amountAMin,
uint256 amountBMin,
address to,
uint256 deadline
)
external
returns (
uint256 amountA,
uint256 amountB,
uint256 liquidity
);
function addLiquidityETH(
address token,
uint256 amountTokenDesired,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline
)
external
payable
returns (
uint256 amountToken,
uint256 amountETH,
uint256 liquidity
);
function removeLiquidity(
address tokenA,
address tokenB,
uint256 liquidity,
uint256 amountAMin,
uint256 amountBMin,
address to,
uint256 deadline
) external returns (uint256 amountA, uint256 amountB);
function removeLiquidityETH(
address token,
uint256 liquidity,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline
) external returns (uint256 amountToken, uint256 amountETH);
function removeLiquidityWithPermit(
address tokenA,
address tokenB,
uint256 liquidity,
uint256 amountAMin,
uint256 amountBMin,
address to,
uint256 deadline,
bool approveMax,
uint8 v,
bytes32 r,
bytes32 s
) external returns (uint256 amountA, uint256 amountB);
function removeLiquidityETHWithPermit(
address token,
uint256 liquidity,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline,
bool approveMax,
uint8 v,
bytes32 r,
bytes32 s
) external returns (uint256 amountToken, uint256 amountETH);
function swapExactTokensForTokens(
uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external returns (uint256[] memory amounts);
function swapTokensForExactTokens(
uint256 amountOut,
uint256 amountInMax,
address[] calldata path,
address to,
uint256 deadline
) external returns (uint256[] memory amounts);
function swapExactETHForTokens(
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external payable returns (uint256[] memory amounts);
function swapTokensForExactETH(
uint256 amountOut,
uint256 amountInMax,
address[] calldata path,
address to,
uint256 deadline
) external returns (uint256[] memory amounts);
function swapExactTokensForETH(
uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external returns (uint256[] memory amounts);
function swapETHForExactTokens(
uint256 amountOut,
address[] calldata path,
address to,
uint256 deadline
) external payable returns (uint256[] memory amounts);
function quote(
uint256 amountA,
uint256 reserveA,
uint256 reserveB
) external pure returns (uint256 amountB);
function getAmountOut(
uint256 amountIn,
uint256 reserveIn,
uint256 reserveOut
) external pure returns (uint256 amountOut);
function getAmountIn(
uint256 amountOut,
uint256 reserveIn,
uint256 reserveOut
) external pure returns (uint256 amountIn);
function getAmountsOut(uint256 amountIn, address[] calldata path)
external
view
returns (uint256[] memory amounts);
function getAmountsIn(uint256 amountOut, address[] calldata path)
external
view
returns (uint256[] memory amounts);
}
// File: contracts\interfaces\IPancakeRouter02.sol
interface IPancakeRouter02 is IPancakeRouter01 {
function removeLiquidityETHSupportingFeeOnTransferTokens(
address token,
uint256 liquidity,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline
) external returns (uint256 amountETH);
function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
address token,
uint256 liquidity,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline,
bool approveMax,
uint8 v,
bytes32 r,
bytes32 s
) external returns (uint256 amountETH);
function swapExactTokensForTokensSupportingFeeOnTransferTokens(
uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external;
function swapExactETHForTokensSupportingFeeOnTransferTokens(
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external payable;
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external;
}
/**
* @dev Implementation of the {IBEP20} interface.
*/
contract CuriosityToken is Context, IBEP20, Ownable, ReentrancyGuard {
using SafeMath for uint256;
using Address for address;
mapping(address => uint256) private _rOwned;
mapping(address => uint256) private _tOwned;
mapping(address => mapping(address => uint256)) private _allowances;
mapping(address => bool) private _isExcludedFromFee;
mapping(address => bool) private _isExcluded;
address[] private _excluded;
uint256 private constant MAX = ~uint256(0);
uint256 private constant _tTOTAL = 1* 1e15 * 10**_DECIMALS;
uint256 private _rTotal = (MAX - (MAX % _tTOTAL));
uint256 private _tFeeTotal;
/**
* @dev Sets the values for {NAME} and {SYMBOL}, and {DECIMALS}
*
* All three of these values are constants: they can only be set once during
* construction.
*/
string private constant _NAME = "Curiosity";
string private constant _SYMBOL = "CURI";
uint8 private constant _DECIMALS = 18;
/**
* @dev Percentage of the static reflection fee.
*/
uint256 public _taxFee = 7;
uint256 private _previousTaxFee = _taxFee;
/**
* @dev Percentage of the liquidity fee.
*/
uint256 public _liquidityFee = 1;
uint256 private _previousLiquidityFee = _liquidityFee;
/**
* @dev Percentage of the auto burn fee.
*/
uint256 public _burnFee = 1;
address public burnAddress = 0x000000000000000000000000000000000000dEaD;
uint256 private _previousBurnFee = _burnFee;
/**
* @dev Percentage of the marketing, development, and team fee.
*/
uint256 public _developmentFee = 1;
address public developmentWallet = 0x0C9186611Cfc19B11D712112fE33E86BF3eB9678;
uint256 private _previousDevelopmentFee = _developmentFee;
IPancakeRouter02 public pancakeswapV2Router;
address public pancakeswapV2Pair;
bool inSwapAndLiquify;
bool public swapAndLiquifyEnabled = false;
/**
* @dev The maximum transaction amount to minimize and break the impact of
* Whale actions.
*/
uint256 public _maxTxAmount = 1e9 * 10**_DECIMALS;
/**
* @dev The amount of token sell to add to the liquidity.
*/
uint256 public numTokensSellToAddToLiquidity = 1e5 * 10**_DECIMALS;
event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap);
event SwapAndLiquifyEnabledUpdated(bool enabled);
event SwapAndLiquify(
uint256 tokensSwapped,
uint256 ethReceived,
uint256 tokensIntoLiquidity
);
modifier lockTheSwap {
inSwapAndLiquify = true;
_;
inSwapAndLiquify = false;
}
constructor () {
_rOwned[_msgSender()] = _rTotal;
IPancakeRouter02 _pancakeswapV2Router =
IPancakeRouter02(0xD99D1c33F9fC3444f8101754aBC46c52416550D1);
// Create a pancakeswap pair
pancakeswapV2Pair = IPancakeFactory(_pancakeswapV2Router.factory()).createPair(
address(this),
_pancakeswapV2Router.WETH()
);
// set the rest of the contract variables
pancakeswapV2Router = _pancakeswapV2Router;
//exclude owner and this contract from fee
_isExcludedFromFee[owner()] = true;
_isExcludedFromFee[address(this)] = true;
emit Transfer(address(0), _msgSender(), _tTOTAL);
}
//to receive BNB from pancakeswapV2Router when swapping
receive() external payable {}
/**
* @dev The owner can withdraw BNB collected in the contract from
* `swapAndLiquify` or if someone sends BNB directly to the contract.
*
* The swapAndLiquify function converts half of the contractTokenBalance
* tokens to BNB. For every swapAndLiquify function call, a small amount
* of BNB remains in the contract. This amount grows over time with the
* swapAndLiquify function being called throughout the life of the contract.
*/
function withdrawBalance(
address payable recipient,
uint256 amount
) external onlyOwner nonReentrant{
require(amount <= address(this).balance,
"BEP20: amount should not exceed the contract balance"
);
recipient.transfer(amount);
}
/**
* @dev See {IBEP20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount)
external
override
returns (bool)
{
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IBEP20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - The caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount)
external
override
returns (bool)
{
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IBEP20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP.
*
* Requirements:
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - The caller must have an allowance for `sender`'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external override returns (bool) {
_transfer(sender, recipient, amount);
_approve(
sender,
_msgSender(),
_allowances[sender][_msgSender()].sub(
amount,
"BEP20: transfer amount exceeds allowance"
)
);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as mitigation for
* problems described in {IBEP20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue)
external
virtual
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][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 mitigation for
* problems described in {IBEP20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have an allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue)
external
virtual
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender].sub(
subtractedValue,
"BEP20: decreased allowance below zero"
)
);
return true;
}
function excludeFromReward(address account) external onlyOwner() {
require(
account != 0x10ED43C718714eb63d5aA57B78B54704E256024E,
'We can not exclude Pancake router.'
);
require(
!_isExcluded[account],
"Account is already excluded"
);
if(_rOwned[account] > 0) {
_tOwned[account] = tokenFromReflection(_rOwned[account]);
}
_isExcluded[account] = true;
_excluded.push(account);
}
function includeInReward(address account) external onlyOwner() {
require(_isExcluded[account], "Account is not excluded");
for (uint256 i = 0; i < _excluded.length; i++) {
if (_excluded[i] == account) {
_excluded[i] = _excluded[_excluded.length - 1];
_tOwned[account] = 0;
_isExcluded[account] = false;
_excluded.pop();
break;
}
}
}
/**
* @dev The owner can exclude specific accounts from Fees.
*/
function excludeFromFee(address account) external onlyOwner {
_isExcludedFromFee[account] = true;
}
/**
* @dev The owner can include specific accounts in Fees.
*/
function includeInFee(address account) external onlyOwner {
_isExcludedFromFee[account] = false;
}
/**
* @dev Call this function to disable all Fees.
* It will be necessary during the Presale stage.
*/
function disableAllFees() external onlyOwner() {
_taxFee = 0;
_previousTaxFee = _taxFee;
_liquidityFee = 0;
_previousLiquidityFee = _liquidityFee;
_burnFee = 0;
_previousBurnFee = _burnFee;
_developmentFee = 0;
_previousDevelopmentFee = _developmentFee;
emit SwapAndLiquifyEnabledUpdated(false);
}
/**
* @dev Call this function to enable Fees after finalizing the Presale.
*/
function enableAllFees() external onlyOwner() {
_taxFee = 7;
_previousTaxFee = _taxFee;
_liquidityFee = 1;
_previousLiquidityFee = _liquidityFee;
_burnFee = 1;
_previousBurnFee = _burnFee;
_developmentFee = 1;
_previousDevelopmentFee = _developmentFee;
emit SwapAndLiquifyEnabledUpdated(false);
}
/**
* @dev Call this function to enable Swap and Liquify.
*/
function setSwapAndLiquifyEnabled(bool _enabled) external onlyOwner {
swapAndLiquifyEnabled = _enabled;
emit SwapAndLiquifyEnabledUpdated(_enabled);
}
/**
* @dev Call this function to change burnFee to zero percent upon a
* certain amount of tokens are burned.
*/
function stopAutoBurn() external onlyOwner() {
_burnFee = 0;
_previousBurnFee = _burnFee;
}
/**
* @dev Update the Router address if Pancakeswap upgrades to a
* newer version.
*/
function setRouterAddress(address newRouter) external onlyOwner {
IPancakeRouter02 _newRouter = IPancakeRouter02(newRouter);
address get_pair = IPancakeFactory(_newRouter.factory()).getPair(
address(this), _newRouter.WETH()
);
//checks if pair already exists
if (get_pair == address(0)) {
pancakeswapV2Pair = IPancakeFactory(_newRouter.factory()).createPair(
address(this), _newRouter.WETH()
);
}
else {
pancakeswapV2Pair = get_pair;
}
pancakeswapV2Router = _newRouter;
}
/**
* @dev Call this function if required to set a different Development
* wallet address.
*/
function setDevelopmentWallet(address newWallet) external onlyOwner() {
developmentWallet = newWallet;
}
/**
* @dev Update the amount of 'numTokensSellToAddToLiquidity'.
*/
function setNumTokensSellToAddToLiquidity(uint256 newAmount) external onlyOwner() {
numTokensSellToAddToLiquidity = newAmount;
}
/**
* @dev Call this function to change the Max transaction amount.
* Adjusting of 'maxTxAmount' will be required during the initial stage.
*/
function setMaxTxAmount(uint256 newAmount) external onlyOwner() {
_maxTxAmount = newAmount;
}
/**
* @dev See {IBEP20-allowance}.
*/
function allowance(address owner, address spender)
external
view
override
returns (uint256)
{
return _allowances[owner][spender];
}
function totalFees() external view returns (uint256) {
return _tFeeTotal;
}
function totalBurned() external view returns (uint256) {
return balanceOf(burnAddress);
}
function isExcludedFromFee(address account) external view returns(bool) {
return _isExcludedFromFee[account];
}
function isExcludedFromReward(address account) external view returns (bool) {
return _isExcluded[account];
}
/**
* @dev Returns the name of the token.
*/
function name() external pure override returns (string memory) {
return _NAME;
}
/**
* @dev Returns the token symbol.
*/
function symbol() external pure override returns (string memory) {
return _SYMBOL;
}
/**
* @dev Returns the token decimals.
*/
function decimals() external pure override returns (uint8) {
return _DECIMALS;
}
/**
* @dev See {IBEP20-totalSupply}.
*/
function totalSupply() external pure override returns (uint256) {
return _tTOTAL;
}
/**
* @dev See {IBEP20-balanceOf}.
*/
function balanceOf(address account) public view override returns (uint256) {
if (_isExcluded[account]) return _tOwned[account];
return tokenFromReflection(_rOwned[account]);
}
function tokenFromReflection(uint256 rAmount)
public
view
returns (uint256)
{
require(
rAmount <= _rTotal,
"Amount must be less than total reflections"
);
uint256 currentRate = _getRate();
return rAmount.div(currentRate);
}
function removeAllFee() private {
_taxFee = 0;
_liquidityFee = 0;
_burnFee = 0;
_developmentFee = 0;
}
function restoreAllFee() private {
_taxFee = 7;
_liquidityFee = 1;
_burnFee = 1;
_developmentFee = 1;
}
/**
* @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 amount) private {
require(owner != address(0), "BEP20: approve from the zero address");
require(spender != address(0), "BEP20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @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` / `from` cannot be the zero address.
* - `recipient` / `to` cannot be the zero address.
* - `sender` / `from` must have a balance of at least `amount`.
*/
function _transfer(
address from, // sender
address to, // recipient
uint256 amount
) private {
require(from != address(0), "BEP20: transfer from the zero address");
require(to != address(0), "BEP20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
// is the token balance of this contract address over the min number of
// tokens that we need to initiate a swap + liquidity lock?
// also, don't get caught in a circular liquidity event.
// also, don't swap & liquify if sender is pancakeswap pair.
uint256 contractTokenBalance = balanceOf(address(this));
bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity;
if (
overMinTokenBalance &&
!inSwapAndLiquify &&
from != pancakeswapV2Pair &&
swapAndLiquifyEnabled
) {
contractTokenBalance = numTokensSellToAddToLiquidity;
//add liquidity
swapAndLiquify(contractTokenBalance);
}
//transfer amount, it will take tax, burn, liquidity fee
_tokenTransfer(from,to,amount);
}
function _transferBothExcluded(
address sender,
address recipient,
uint256 tAmount
) private {
(uint256 rAmount,
uint256 rTransferAmount,
uint256 rFee,
uint256 tTransferAmount,
uint256 tFee,
uint256 tLiquidity
) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _takeLiquidity(uint256 tLiquidity) private {
uint256 currentRate = _getRate();
uint256 rLiquidity = tLiquidity.mul(currentRate);
_rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity);
if(_isExcluded[address(this)])
_tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity);
}
function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap {
// split the contract balance into halves
uint256 half = contractTokenBalance.div(2);
uint256 otherHalf = contractTokenBalance.sub(half);
// capture the contract's current BNB balance.
// this is so that we can capture exactly the amount of BNB that the
// swap creates and does not make the liquidity event include any BNB that
// has been manually sent to the contract
uint256 initialBalance = address(this).balance;
// swap tokens for BNB
swapTokensForEth(half); // this breaks the BNB
// how much BNB did we just swap into?
uint256 newBalance = address(this).balance.sub(initialBalance);
// add liquidity to Pancakeswap
addLiquidity(otherHalf, newBalance);
emit SwapAndLiquify(half, newBalance, otherHalf);
}
function swapTokensForEth(uint256 tokenAmount) private {
// generate the pancakeswap pair path of token -> weth (wbnb)
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = pancakeswapV2Router.WETH();
_approve(address(this), address(pancakeswapV2Router), tokenAmount);
// make the swap
pancakeswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // accept any amount of BNB
path,
address(this),
block.timestamp
);
}
function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
// approve token transfer to cover all possible scenarios
_approve(address(this), address(pancakeswapV2Router), tokenAmount);
// add the liquidity
pancakeswapV2Router.addLiquidityETH{value: ethAmount}(
address(this),
tokenAmount,
0, // slippage is unavoidable
0, // slippage is unavoidable
address(this),
block.timestamp
);
}
//this method is responsible for taking all fee, if takeFee is true
function _tokenTransfer(address sender, address recipient, uint256 amount) private {
if(_isExcludedFromFee[sender] || _isExcludedFromFee[recipient]){
removeAllFee();
}
else{
require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");
}
//Calculate burn amount and development amount
uint256 burnAmt = amount.mul(_burnFee).div(100);
uint256 developmentAmt = amount.mul(_developmentFee).div(100);
if (_isExcluded[sender] && !_isExcluded[recipient]) {
_transferFromExcluded(sender, recipient, (amount.sub(burnAmt).sub(developmentAmt)));
} else if (!_isExcluded[sender] && _isExcluded[recipient]) {
_transferToExcluded(sender, recipient, (amount.sub(burnAmt).sub(developmentAmt)));
} else if (_isExcluded[sender] && _isExcluded[recipient]) {
_transferBothExcluded(sender, recipient, (amount.sub(burnAmt).sub(developmentAmt)));
} else {
_transferStandard(sender, recipient, (amount.sub(burnAmt).sub(developmentAmt)));
}
//Temporarily remove fees to transfer to burn address and development wallet
_taxFee = 0;
_liquidityFee = 0;
//Send transfers to burn address and development wallet
_transferStandard(sender, burnAddress, burnAmt);
_transferStandard(sender, developmentWallet, developmentAmt);
//Restore tax and liquidity fees
_taxFee = _previousTaxFee;
_liquidityFee = _previousLiquidityFee;
if(_isExcludedFromFee[sender] || _isExcludedFromFee[recipient])
restoreAllFee();
}
function _transferStandard(
address sender,
address recipient,
uint256 tAmount
) private {
(
uint256 rAmount,
uint256 rTransferAmount,
uint256 rFee,
uint256 tTransferAmount,
uint256 tFee,
uint256 tLiquidity
) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferToExcluded(
address sender,
address recipient,
uint256 tAmount
) private {
(
uint256 rAmount,
uint256 rTransferAmount,
uint256 rFee,
uint256 tTransferAmount,
uint256 tFee,
uint256 tLiquidity
) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferFromExcluded(
address sender,
address recipient,
uint256 tAmount
) private {
(
uint256 rAmount,
uint256 rTransferAmount,
uint256 rFee,
uint256 tTransferAmount,
uint256 tFee,
uint256 tLiquidity
) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _reflectFee(uint256 rFee, uint256 tFee) private {
_rTotal = _rTotal.sub(rFee);
_tFeeTotal = _tFeeTotal.add(tFee);
}
function _getValues(uint256 tAmount)
private
view
returns (
uint256,
uint256,
uint256,
uint256,
uint256,
uint256
)
{
(uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) =
_getTValues(tAmount);
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee) =
_getRValues(tAmount, tFee, tLiquidity, _getRate());
return (
rAmount,
rTransferAmount,
rFee,
tTransferAmount,
tFee,
tLiquidity
);
}
function _getTValues(uint256 tAmount)
private
view
returns (
uint256,
uint256,
uint256
)
{
uint256 tFee = calculateTaxFee(tAmount);
uint256 tLiquidity = calculateLiquidityFee(tAmount);
uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity);
return (tTransferAmount, tFee, tLiquidity);
}
function _getRate() private view returns(uint256) {
(uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
return rSupply.div(tSupply);
}
function _getCurrentSupply() private view returns(uint256, uint256) {
uint256 rSupply = _rTotal;
uint256 tSupply = _tTOTAL;
for (uint256 i = 0; i < _excluded.length; i++) {
if (
_rOwned[_excluded[i]] > rSupply ||
_tOwned[_excluded[i]] > tSupply
) return (_rTotal, _tTOTAL);
rSupply = rSupply.sub(_rOwned[_excluded[i]]);
tSupply = tSupply.sub(_tOwned[_excluded[i]]);
}
if (rSupply < _rTotal.div(_tTOTAL)) return (_rTotal, _tTOTAL);
return (rSupply, tSupply);
}
function calculateTaxFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_taxFee).div(
10**2
);
}
function calculateLiquidityFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_liquidityFee).div(
10**2
);
}
function _getRValues(
uint256 tAmount,
uint256 tFee,
uint256 tLiquidity,
uint256 currentRate
)
private
pure
returns (
uint256,
uint256,
uint256
)
{
uint256 rAmount = tAmount.mul(currentRate);
uint256 rFee = tFee.mul(currentRate);
uint256 rLiquidity = tLiquidity.mul(currentRate);
uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity);
return (rAmount, rTransferAmount, rFee);
}
}