Contract Source Code:
// SPDX-License-Identifier: MIT
// ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
// ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
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// ooooooooooooooooooo:. ',. .,ok0XXXXXNNNNNXXXXXXXXXXXXKKKKKKKKK0000000Oxolc. .:ooooooooooooooooooooooooo
// ooooooooooooooooooo:. .;' .;dOKXXXXXNNNNXXXXXXXXXXXXXXKKKKKKKKK0000000Okdll:. ,loooooooooooooooooooooooo
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// ooooooooooooooooooo:. ,l;;dO0KXXXXXXXXXXXXXXXXXXXXXXXXKKKKKKKKK000000000Oxool:' .:oooooooooooooooooooooooo
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// oooooooooooooooooooo;.:xxoc,''.'oOOl;d00kl:lc;,;okxoloxOOo'.'cool;..,lxxxo;.'cxOo,.,,';,....;;;cccloooooooooooooooooooooooo
// oooooooooooooooooooo:.,xOkoclo:;okOx;:k00kdc::::clodxO0kl,,:ldxxd:..,dOOxo:,;:c;,,;c:;;. .;cooooooooooooooooooooooooooooooo
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// oooooooooooooooooooooo:'.,:::cdxkkkkO0000OOkxxxxxxxkO00KK0OOOOOOOxl;cxxdlc:::::;;:::::;..,loooooooooooooooooooooooooooooooo
// oooooooooooooooooooooool;. .cxkkkkOOO0000KKKKKKKKKKKK0OOOOOO000ko;,oOOOOOkkkxxxddolc;..;ooooooooooooooooooooooooooooooooo
// ooooooooooooooooooooooool' .:dkkOOOOOOO0000KKKKKKKKK0kkxollldxxo:'.:xOOOOOOOOkkkkxoc,..cooooooooooooooooooooooooooooooooo
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// ooooooooooooooooooooooool, 'okkOOOOOOOOO0000000KKKKK0xdxxxoc;'...,cdkOOOkkkxxddool:..;oooooooooooooooooooooooooooooooooo
// ooooooooooooooooooooooooo:,. .cxkOOOOOOOOOOO0000KKKKKKKK00OOxollccldkOOOOOkkxddooolc;..:oooooooooooooooooooooooooooooooooo
// oooooooooooooooooooooooooooc,..,okkOOOOOOOOOOO000KKKKKK000000OkOOkkkkkOOOOOkxxdooool:'.'loooooooooooooooooooooooooooooooooo
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// oooooooooooooooooooooooooooooooooo:..':odxkkxxxxxkOOOOkxdolllcc::clodxxxxdoc:;;,...:ooooooooooooooooooooooooooooooooooooooo
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// ooooooooooooooooooooooooooooool:'.. .cddl;...,:ldxxkkOOOOOOOOOOOkxdddolc;,'. ..;looooooooooooooooooooooooooooooooooooooo
// ooooooooooooooooooooooooooool;..... .cddxdoc,...';coddxxxxxxdddddoolc:;'.. .. .,cooooooooooooooooooooooooooooooooooooo
// ooooooooooooooooooooooooool:'...,,. .:dxxxkkxoc;'...',;::::::::;;,,'... .,,. . .':ooooooooooooooooooooooooooooooooooo
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// oooooooooooooooooolc:;,''''...:kKXOl..cxkOOOOOOOOOOkkkO0KKK00Od:... .';c:'.;lol:;'. ..',:cloooooooooooooooooooo
// oooooooooooollc;,'.....'''.. .oOKNX0d;'cdkOOOOOOOOOOOkxxkO00Oko:'...,cl:,:dkxoc:;,. ..',;:lloooooooooooooo
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// c;,'.... ...''''''....'oOOKNNNNKx:,;okOOOOOOOOOOkxolcc;,,;:ccccd0K0Oxl:;;;,............. ....',;:cl
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// ,.............''''''''''. .::':k0OOKXNNWNXOo;,:dkOOOOOOOOkddollclokKXXXK0xlcccc:' ................ ................
// ;...........'''''''''''. ,dd'.oO00O0XNNWNNXOo;,;lxkOOOOkxoolcldOKXXXXX0xollooc'..................... .....................
// :'''''....'''''''''''... .l00l.,d0KK000XNNWWNX0d:,,:ldddlcllokKXNNNNXKOxoloddo,...................... .....................
// :'''....'''''''''''.... 'xXXO:.,x0KXXK00KXNNNNXOo'.','.,cxk0XNNNNXK0kdooxkkd;..;'.................... ....................
// :''....''''''''''...... ;x0KKk:.,dOKNNNXK0KXXXKx;........;coOKXXK0OkxddkOkd;..::...................... ...................
// :'...'''''''''''...... .o0000Okc.'oOKXNNNNXK0kc..:cccllc,...,oO0000OxkOOOd;.'od;...................... ..................
// :....'''''''''........ ,ONNNXXK0o''lk0KNNNNKo'.':ldxkkxdl,.. .:xO00OO00Od;.,xKx'....................... .................
// ;.....''''''.......... :0NNNNNNNXx,.lk0XNXk:. .lxkkkxddo:. ..'ok0000Od;.;kXKl......................... .................
// ;.......'''......'''.. .cKNNNNNNNNXk,.ck00o'';..;xOOxxddc. 'c;..cxO0Oo,.:kXNk,.''..................... ................
// :''..........'''''''.. .oKXXXXNNNNNNk;'cd:':k0o..ckkxxdl' .,okOd'.:xko,.cOXNKl..''....... ......... .................
// :'''......''',,'''''. 'xXNNNXXXNNNNNO:'',lO0K0l.'dxddo; ,coOXX0d,.;c,'lOXNNk,.''.......... ..... ....................
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// :'....',,,,,,,'''''. .oKKKKKKKKKXXXNNNNNNNNXXO;.;,.'oo' .;odOKK000klcoOXNNNO;.''.............. .........................
pragma solidity ^0.8.7;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
contract SBUCKS is ERC20, Ownable {
constructor() ERC20("SBUCKS", "SBUCKS"){}
/// turn on/off contributions
bool public allowContributions;
/// a minimum contribution to participate in the presale
uint256 public constant MIN_CONTRIBUTION = .025 ether;
/// limit the maximum contribution for each wallet
uint256 public constant MAX_CONTRIBUTION = .35 ether;
/// the maximum amount of eth that this contract will accept for presale
uint256 public constant HARD_CAP = 17.5 ether;
/// total number of tokens available
uint256 public constant MAX_SUPPLY = 696969696969 * 10 ** 18;
/// 40% of tokens reserved for presale
uint256 public constant PRESALE_SUPPLY = 331060606060 * 10 ** 18;
/// 60% for LP and team
uint256 public constant RESERVE_MAX_SUPPLY = 365909090909 * 10 ** 18;
/// used to track the total contributions for the presale
uint256 public TOTAL_CONTRIBUTED;
/// used to track the total number of contributoors
uint256 public NUMBER_OF_CONTRIBUTOORS;
/// mapping of whitelist addresses
mapping(address => bool) public whiteLists;
/// mapping of blacklist addresses
mapping(address => bool) public blackLists;
/// boolean for public sale
bool public publicSale = false;
/// boolean for limiting holdings initially
bool public limited;
/// set max holding amount
uint256 public maxHoldingAmount;
/// uniswapV2Pair address
address public uniswapV2Pair;
/// a struct used to keep track of each contributoors address and contribution amount
struct Contribution {
address addr;
uint256 amount;
}
function setRule(bool _limited, uint256 _maxHoldingAmount) external onlyOwner {
limited = _limited;
maxHoldingAmount = _maxHoldingAmount;
}
function whiteList(address _address, bool _isWhiteListing) external onlyOwner{
whiteLists[_address] = _isWhiteListing;
}
function blackList(address _address, bool _isBlackListing) external onlyOwner{
blackLists[_address] = _isBlackListing;
}
function addBatchWhiteList(address[] calldata _address) external onlyOwner {
for(uint i = 0; i < _address.length; i++) {
whiteLists[_address[i]] = true;
}
}
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) override internal virtual {
require(!blackLists[to] && !blackLists[from], "Blacklisted");
if (uniswapV2Pair == address(0) && from != address(0)) {
require(from == owner(), "trading is not started");
return;
}
if(limited && from == uniswapV2Pair) {
require(super.balanceOf(to) + amount <= maxHoldingAmount, "Forbid");
}
}
/// mapping of contributions
mapping (uint256 => Contribution) public contribution;
/// index of an address to it's contribition information
mapping (address => uint256) public contributoor;
/// collect presale contributions
function sendToPresale() public payable {
if(!publicSale) {
require(whiteLists[msg.sender], "You are not whitelisted.");
}
/// look up the sender's current contribution amount in the mapping
uint256 currentContribution = contribution[contributoor[msg.sender]].amount;
/// initialize a contribution index so we can keep track of this address' contributions
uint256 contributionIndex;
require(msg.value >= MIN_CONTRIBUTION, "Contribution too low");
/// check to see if contributions are allowed
require (allowContributions, "Contributions not allowed");
/// enforce per-wallet contribution limit
require (msg.value + currentContribution <= MAX_CONTRIBUTION, "Contribution exceeds per wallet limit");
/// enforce hard cap
require (msg.value + TOTAL_CONTRIBUTED <= HARD_CAP, "Contribution exceeds hard cap");
if (contributoor[msg.sender] != 0){
/// no need to increase the number of contributors since this person already added
contributionIndex = contributoor[msg.sender];
} else {
/// keep track of each new contributor with a unique index
contributionIndex = NUMBER_OF_CONTRIBUTOORS + 1;
NUMBER_OF_CONTRIBUTOORS++;
}
/// add the contribution to the amount contributed
TOTAL_CONTRIBUTED = TOTAL_CONTRIBUTED + msg.value;
/// keep track of the address' contributions so far
contributoor[msg.sender] = contributionIndex;
contribution[contributionIndex].addr = msg.sender;
contribution[contributionIndex].amount += msg.value;
}
function airdropPresale() external onlyOwner {
/// determine the price per token
uint256 pricePerToken = (TOTAL_CONTRIBUTED * 10 ** 18)/PRESALE_SUPPLY;
/// loop over each contribution and distribute tokens
for (uint256 i = 1; i <= NUMBER_OF_CONTRIBUTOORS; i++) {
/// convert contribution to 18 decimals
uint256 contributionAmount = contribution[i].amount * 10 ** 18;
/// calculate the percentage of the pool based on the address' contribution
uint256 numberOfTokensToMint = contributionAmount/pricePerToken;
/// mint the tokens to the address
_mint(contribution[i].addr, numberOfTokensToMint);
}
/// calculate the remaining supply
uint256 numberToMint = MAX_SUPPLY - totalSupply();
/// don't allow the dev mint until the tokens have been airdropped
require (numberToMint <= RESERVE_MAX_SUPPLY, "Dev mint limited to reserve max");
/// mint the remaining supply to the dev's wallet
_mint(msg.sender, numberToMint);
}
/// set whether or not the contract allows contributions
function setAllowContributions(bool _value) external onlyOwner {
allowContributions = _value;
}
/// if there are not enough contributions or we decide this sucks, refund everyone their eth
function refundEveryone() external onlyOwner {
for (uint256 i = 1; i <= NUMBER_OF_CONTRIBUTOORS; i++) {
address payable refundAddress = payable(contribution[i].addr);
/// refund the contribution
refundAddress.transfer(contribution[i].amount);
}
}
/// allows the owner to withdraw the funds in this contract
function withdrawBalance(address payable _address) external onlyOwner {
(bool success, ) = _address.call{value: address(this).balance}("");
require(success, "Withdraw failed");
}
/// toggle public sale
function togglePublic() external onlyOwner() {
publicSale = !publicSale;
}
/// allows the owner to set uniswapv2pair
function setUniswapV2Pair(address _uniswapV2Pair) external onlyOwner {
uniswapV2Pair = _uniswapV2Pair;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @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.
*/
abstract 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() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. 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() public virtual onlyOwner {
_transferOwnership(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) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.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.openzeppelin.com/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;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_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;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_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;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_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 {}
}
// SPDX-License-Identifier: MIT
// 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;
}
}
// SPDX-License-Identifier: MIT
// 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.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);
}