Transaction Hash:
Block:
13952009 at Jan-06-2022 01:17:51 PM +UTC
Transaction Fee:
0.011842704513473078 ETH
$22.53
Gas Used:
116,362 Gas / 101.774673119 Gwei
Emitted Events:
46 |
RoarToken.Transfer( from=[Receiver] RoarStaking, to=[Sender] 0x84beae50c00b3f3036d408b54ec665c03738a03d, value=1588451666666666031286 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x84BEAE50...03738A03D |
0.019127089552502349 Eth
Nonce: 45
|
0.007284385039029271 Eth
Nonce: 46
| 0.011842704513473078 | ||
0x9c6Ba2b5...8752f1DDc | |||||
0xcbbA83a4...6627da018 | |||||
0xEA674fdD...16B898ec8
Miner
| (Ethermine) | 2,545.966696840458420836 Eth | 2,545.96723085106684196 Eth | 0.000534010608421124 |
Execution Trace
RoarStaking.claimRewards( tokenIds=[3697, 3920, 5853, 7894, 8199, 9524, 9922] )
-
RoarToken.transfer( recipient=0x84BEAE50c00b3F3036d408B54Ec665c03738A03D, amount=1588451666666666031286 ) => ( True )
claimRewards[RoarStaking (ln:84)]
min[RoarStaking (ln:86)]
calculateReward[RoarStaking (ln:88)]
transfer[RoarStaking (ln:92)]
File 1 of 2: RoarStaking
File 2 of 2: RoarToken
// SPDX-License-Identifier: Unlicensed pragma solidity ^0.8.0; import "@openzeppelin/contracts/access/Ownable.sol"; import "@openzeppelin/contracts/security/Pausable.sol"; import "@openzeppelin/contracts/token/ERC20/IERC20.sol"; import "@openzeppelin/contracts/token/ERC721/IERC721.sol"; import "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol"; import "@openzeppelin/contracts/utils/math/Math.sol"; import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol"; contract RoarStaking is Ownable, ERC721Holder, Pausable { using EnumerableSet for EnumerableSet.UintSet; IERC721 public roaringLeadersContractInstance; IERC20 public roarTokenContractInstance; // Number of tokens per block. There are approx 6k blocks per day and 10 tokens are represented by 10^19 (after considering decimals). uint256 public rate; // Expiration block number. uint256 public expirationBlockNumber; // Mapping of address to token numbers deposited mapping(address => EnumerableSet.UintSet) private _deposits; // Mapping of address -> token -> block number mapping(address => mapping(uint256 => uint256)) public _depositBlocks; constructor(address roaringLeadersContractAddress, uint256 initialRate, uint256 numberOfExpirationBlocks, address roarTokenAddress) { roaringLeadersContractInstance = IERC721(roaringLeadersContractAddress); rate = initialRate; expirationBlockNumber = block.number + numberOfExpirationBlocks; roarTokenContractInstance = IERC20(roarTokenAddress); _pause(); } function setAddresses(address roaringLeadersContractAddress, address roarTokenAddress) public onlyOwner { roaringLeadersContractInstance = IERC721(roaringLeadersContractAddress); roarTokenContractInstance = IERC20(roarTokenAddress); } function setRate(uint256 newRate) public onlyOwner { rate = newRate; } function setExpiration(uint256 numberOfExpirationBlocks) public onlyOwner { expirationBlockNumber = block.number + numberOfExpirationBlocks; } function pause() public onlyOwner { _pause(); } function unpause() public onlyOwner { _unpause(); } function depositsOf(address owner) external view returns (uint256[] memory) { EnumerableSet.UintSet storage depositSet = _deposits[owner]; uint256[] memory tokenIds = new uint256[](depositSet.length()); for (uint256 i; i < depositSet.length(); i++) { tokenIds[i] = depositSet.at(i); } return tokenIds; } function hasDeposits(address owner, uint256[] memory tokenIds) external view returns (bool) { EnumerableSet.UintSet storage depositSet = _deposits[owner]; for (uint256 i = 0; i < tokenIds.length; i++) { if (! depositSet.contains(tokenIds[i])) { return false; } } return true; } function hasDepositsOrOwns(address owner, uint256[] memory tokenIds) external view returns (bool) { EnumerableSet.UintSet storage depositSet = _deposits[owner]; for (uint256 i = 0; i < tokenIds.length; i++) { if (! depositSet.contains(tokenIds[i]) && roaringLeadersContractInstance.ownerOf(tokenIds[i]) != owner) { return false; } } return true; } function calculateRewards(address owner, uint256[] memory tokenIds) external view returns (uint256) { uint256 reward = 0; for (uint256 i; i < tokenIds.length; i++) { reward += calculateReward(owner, tokenIds[i]); } return reward; } function calculateReward(address owner, uint256 tokenId) public view returns (uint256) { require(Math.min(block.number, expirationBlockNumber) >= _depositBlocks[owner][tokenId], "Invalid block numbers"); return rate * (_deposits[owner].contains(tokenId) ? 1 : 0) * (Math.min(block.number, expirationBlockNumber) - _depositBlocks[owner][tokenId]); } function claimRewards(uint256[] calldata tokenIds) public whenNotPaused { uint256 reward = 0; uint256 currentBlock = Math.min(block.number, expirationBlockNumber); for (uint256 i; i < tokenIds.length; i++) { reward += calculateReward(msg.sender, tokenIds[i]); _depositBlocks[msg.sender][tokenIds[i]] = currentBlock; } if (reward > 0) { roarTokenContractInstance.transfer(msg.sender, reward); } } function deposit(uint256[] calldata tokenIds) external whenNotPaused { require(msg.sender != address(roaringLeadersContractInstance), "Invalid address"); uint256 currentBlock = Math.min(block.number, expirationBlockNumber); for (uint256 i = 0; i < tokenIds.length; i++) { roaringLeadersContractInstance.safeTransferFrom(msg.sender, address(this), tokenIds[i], ""); _deposits[msg.sender].add(tokenIds[i]); _depositBlocks[msg.sender][tokenIds[i]] = currentBlock; } } function withdraw(uint256[] calldata tokenIds) external whenNotPaused { claimRewards(tokenIds); for (uint256 i; i < tokenIds.length; i++) { require(_deposits[msg.sender].contains(tokenIds[i]), "This token has not been deposited"); _deposits[msg.sender].remove(tokenIds[i]); roaringLeadersContractInstance.safeTransferFrom(address(this), msg.sender, tokenIds[i], ""); } } function withdrawTokens(uint256 tokenAmount) external onlyOwner { roarTokenContractInstance.transfer(msg.sender, tokenAmount); } }// SPDX-License-Identifier: MIT 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 () { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view virtual 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 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 { 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) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../utils/Context.sol"; /** * @dev Contract module which allows children to implement an emergency stop * mechanism that can be triggered by an authorized account. * * This module is used through inheritance. It will make available the * modifiers `whenNotPaused` and `whenPaused`, which can be applied to * the functions of your contract. Note that they will not be pausable by * simply including this module, only once the modifiers are put in place. */ abstract contract Pausable is Context { /** * @dev Emitted when the pause is triggered by `account`. */ event Paused(address account); /** * @dev Emitted when the pause is lifted by `account`. */ event Unpaused(address account); bool private _paused; /** * @dev Initializes the contract in unpaused state. */ constructor () { _paused = false; } /** * @dev Returns true if the contract is paused, and false otherwise. */ function paused() public view virtual returns (bool) { return _paused; } /** * @dev Modifier to make a function callable only when the contract is not paused. * * Requirements: * * - The contract must not be paused. */ modifier whenNotPaused() { require(!paused(), "Pausable: paused"); _; } /** * @dev Modifier to make a function callable only when the contract is paused. * * Requirements: * * - The contract must be paused. */ modifier whenPaused() { require(paused(), "Pausable: not paused"); _; } /** * @dev Triggers stopped state. * * Requirements: * * - The contract must not be paused. */ function _pause() internal virtual whenNotPaused { _paused = true; emit Paused(_msgSender()); } /** * @dev Returns to normal state. * * Requirements: * * - The contract must be paused. */ function _unpause() internal virtual whenPaused { _paused = false; emit Unpaused(_msgSender()); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @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 `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 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 `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); } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../../utils/introspection/IERC165.sol"; /** * @dev Required interface of an ERC721 compliant contract. */ interface IERC721 is IERC165 { /** * @dev Emitted when `tokenId` token is transferred from `from` to `to`. */ event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token. */ event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets. */ event ApprovalForAll(address indexed owner, address indexed operator, bool approved); /** * @dev Returns the number of tokens in ``owner``'s account. */ function balanceOf(address owner) external view returns (uint256 balance); /** * @dev Returns the owner of the `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function ownerOf(uint256 tokenId) external view returns (address owner); /** * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients * are aware of the ERC721 protocol to prevent tokens from being forever locked. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom(address from, address to, uint256 tokenId) external; /** * @dev Transfers `tokenId` token from `from` to `to`. * * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * * Emits a {Transfer} event. */ function transferFrom(address from, address to, uint256 tokenId) external; /** * @dev Gives permission to `to` to transfer `tokenId` token to another account. * The approval is cleared when the token is transferred. * * Only a single account can be approved at a time, so approving the zero address clears previous approvals. * * Requirements: * * - The caller must own the token or be an approved operator. * - `tokenId` must exist. * * Emits an {Approval} event. */ function approve(address to, uint256 tokenId) external; /** * @dev Returns the account approved for `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function getApproved(uint256 tokenId) external view returns (address operator); /** * @dev Approve or remove `operator` as an operator for the caller. * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller. * * Requirements: * * - The `operator` cannot be the caller. * * Emits an {ApprovalForAll} event. */ function setApprovalForAll(address operator, bool _approved) external; /** * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`. * * See {setApprovalForAll} */ function isApprovedForAll(address owner, address operator) external view returns (bool); /** * @dev Safely transfers `tokenId` token from `from` to `to`. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external; } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @title ERC721 token receiver interface * @dev Interface for any contract that wants to support safeTransfers * from ERC721 asset contracts. */ interface IERC721Receiver { /** * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom} * by `operator` from `from`, this function is called. * * It must return its Solidity selector to confirm the token transfer. * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted. * * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`. */ function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4); } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../IERC721Receiver.sol"; /** * @dev Implementation of the {IERC721Receiver} interface. * * Accepts all token transfers. * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}. */ contract ERC721Holder is IERC721Receiver { /** * @dev See {IERC721Receiver-onERC721Received}. * * Always returns `IERC721Receiver.onERC721Received.selector`. */ function onERC721Received(address, address, uint256, bytes memory) public virtual override returns (bytes4) { return this.onERC721Received.selector; } } // SPDX-License-Identifier: MIT 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) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Standard math utilities missing in the Solidity language. */ library Math { /** * @dev Returns the largest of two numbers. */ function max(uint256 a, uint256 b) internal pure returns (uint256) { return a >= b ? a : b; } /** * @dev Returns the smallest of two numbers. */ function min(uint256 a, uint256 b) internal pure returns (uint256) { return a < b ? a : b; } /** * @dev Returns the average of two numbers. The result is rounded towards * zero. */ function average(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b) / 2 can overflow, so we distribute return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Library for managing * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive * types. * * Sets have the following properties: * * - Elements are added, removed, and checked for existence in constant time * (O(1)). * - Elements are enumerated in O(n). No guarantees are made on the ordering. * * ``` * contract Example { * // Add the library methods * using EnumerableSet for EnumerableSet.AddressSet; * * // Declare a set state variable * EnumerableSet.AddressSet private mySet; * } * ``` * * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`) * and `uint256` (`UintSet`) are supported. */ library EnumerableSet { // To implement this library for multiple types with as little code // repetition as possible, we write it in terms of a generic Set type with // bytes32 values. // The Set implementation uses private functions, and user-facing // implementations (such as AddressSet) are just wrappers around the // underlying Set. // This means that we can only create new EnumerableSets for types that fit // in bytes32. struct Set { // Storage of set values bytes32[] _values; // Position of the value in the `values` array, plus 1 because index 0 // means a value is not in the set. mapping (bytes32 => uint256) _indexes; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function _add(Set storage set, bytes32 value) private returns (bool) { if (!_contains(set, value)) { set._values.push(value); // The value is stored at length-1, but we add 1 to all indexes // and use 0 as a sentinel value set._indexes[value] = set._values.length; return true; } else { return false; } } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function _remove(Set storage set, bytes32 value) private returns (bool) { // We read and store the value's index to prevent multiple reads from the same storage slot uint256 valueIndex = set._indexes[value]; if (valueIndex != 0) { // Equivalent to contains(set, value) // To delete an element from the _values array in O(1), we swap the element to delete with the last one in // the array, and then remove the last element (sometimes called as 'swap and pop'). // This modifies the order of the array, as noted in {at}. uint256 toDeleteIndex = valueIndex - 1; uint256 lastIndex = set._values.length - 1; // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement. bytes32 lastvalue = set._values[lastIndex]; // Move the last value to the index where the value to delete is set._values[toDeleteIndex] = lastvalue; // Update the index for the moved value set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex // Delete the slot where the moved value was stored set._values.pop(); // Delete the index for the deleted slot delete set._indexes[value]; return true; } else { return false; } } /** * @dev Returns true if the value is in the set. O(1). */ function _contains(Set storage set, bytes32 value) private view returns (bool) { return set._indexes[value] != 0; } /** * @dev Returns the number of values on the set. O(1). */ function _length(Set storage set) private view returns (uint256) { return set._values.length; } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function _at(Set storage set, uint256 index) private view returns (bytes32) { require(set._values.length > index, "EnumerableSet: index out of bounds"); return set._values[index]; } // Bytes32Set struct Bytes32Set { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(Bytes32Set storage set, bytes32 value) internal returns (bool) { return _add(set._inner, value); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) { return _remove(set._inner, value); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) { return _contains(set._inner, value); } /** * @dev Returns the number of values in the set. O(1). */ function length(Bytes32Set storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) { return _at(set._inner, index); } // AddressSet struct AddressSet { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(AddressSet storage set, address value) internal returns (bool) { return _add(set._inner, bytes32(uint256(uint160(value)))); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(AddressSet storage set, address value) internal returns (bool) { return _remove(set._inner, bytes32(uint256(uint160(value)))); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(AddressSet storage set, address value) internal view returns (bool) { return _contains(set._inner, bytes32(uint256(uint160(value)))); } /** * @dev Returns the number of values in the set. O(1). */ function length(AddressSet storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(AddressSet storage set, uint256 index) internal view returns (address) { return address(uint160(uint256(_at(set._inner, index)))); } // UintSet struct UintSet { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(UintSet storage set, uint256 value) internal returns (bool) { return _add(set._inner, bytes32(value)); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(UintSet storage set, uint256 value) internal returns (bool) { return _remove(set._inner, bytes32(value)); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(UintSet storage set, uint256 value) internal view returns (bool) { return _contains(set._inner, bytes32(value)); } /** * @dev Returns the number of values on the set. O(1). */ function length(UintSet storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(UintSet storage set, uint256 index) internal view returns (uint256) { return uint256(_at(set._inner, index)); } }
File 2 of 2: RoarToken
// SPDX-License-Identifier: Unlicensed pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol"; import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol"; import "@openzeppelin/contracts/access/AccessControl.sol"; contract RoarToken is ERC20, ERC20Capped, ERC20Burnable, AccessControl { bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE"); constructor(string memory name, string memory symbol) ERC20(name, symbol) ERC20Capped(425000000000000000000000000) { _mint(msg.sender, 425000000 * 10 ** decimals()); _setupRole(DEFAULT_ADMIN_ROLE, msg.sender); _setupRole(MINTER_ROLE, msg.sender); } function mint(address to, uint256 amount) public onlyRole(MINTER_ROLE) { _mint(to, amount); } function _mint(address to, uint256 amount) internal override(ERC20, ERC20Capped) { super._mint(to, amount); } }// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../utils/Context.sol"; import "../utils/Strings.sol"; import "../utils/introspection/ERC165.sol"; /** * @dev External interface of AccessControl declared to support ERC165 detection. */ interface IAccessControl { function hasRole(bytes32 role, address account) external view returns (bool); function getRoleAdmin(bytes32 role) external view returns (bytes32); function grantRole(bytes32 role, address account) external; function revokeRole(bytes32 role, address account) external; function renounceRole(bytes32 role, address account) external; } /** * @dev Contract module that allows children to implement role-based access * control mechanisms. This is a lightweight version that doesn't allow enumerating role * members except through off-chain means by accessing the contract event logs. Some * applications may benefit from on-chain enumerability, for those cases see * {AccessControlEnumerable}. * * Roles are referred to by their `bytes32` identifier. These should be exposed * in the external API and be unique. The best way to achieve this is by * using `public constant` hash digests: * * ``` * bytes32 public constant MY_ROLE = keccak256("MY_ROLE"); * ``` * * Roles can be used to represent a set of permissions. To restrict access to a * function call, use {hasRole}: * * ``` * function foo() public { * require(hasRole(MY_ROLE, msg.sender)); * ... * } * ``` * * Roles can be granted and revoked dynamically via the {grantRole} and * {revokeRole} functions. Each role has an associated admin role, and only * accounts that have a role's admin role can call {grantRole} and {revokeRole}. * * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means * that only accounts with this role will be able to grant or revoke other * roles. More complex role relationships can be created by using * {_setRoleAdmin}. * * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to * grant and revoke this role. Extra precautions should be taken to secure * accounts that have been granted it. */ abstract contract AccessControl is Context, IAccessControl, ERC165 { struct RoleData { mapping (address => bool) members; bytes32 adminRole; } mapping (bytes32 => RoleData) private _roles; bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00; /** * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole` * * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite * {RoleAdminChanged} not being emitted signaling this. * * _Available since v3.1._ */ event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole); /** * @dev Emitted when `account` is granted `role`. * * `sender` is the account that originated the contract call, an admin role * bearer except when using {_setupRole}. */ event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender); /** * @dev Emitted when `account` is revoked `role`. * * `sender` is the account that originated the contract call: * - if using `revokeRole`, it is the admin role bearer * - if using `renounceRole`, it is the role bearer (i.e. `account`) */ event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender); /** * @dev Modifier that checks that an account has a specific role. Reverts * with a standardized message including the required role. * * The format of the revert reason is given by the following regular expression: * * /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/ * * _Available since v4.1._ */ modifier onlyRole(bytes32 role) { _checkRole(role, _msgSender()); _; } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId); } /** * @dev Returns `true` if `account` has been granted `role`. */ function hasRole(bytes32 role, address account) public view override returns (bool) { return _roles[role].members[account]; } /** * @dev Revert with a standard message if `account` is missing `role`. * * The format of the revert reason is given by the following regular expression: * * /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/ */ function _checkRole(bytes32 role, address account) internal view { if(!hasRole(role, account)) { revert(string(abi.encodePacked( "AccessControl: account ", Strings.toHexString(uint160(account), 20), " is missing role ", Strings.toHexString(uint256(role), 32) ))); } } /** * @dev Returns the admin role that controls `role`. See {grantRole} and * {revokeRole}. * * To change a role's admin, use {_setRoleAdmin}. */ function getRoleAdmin(bytes32 role) public view override returns (bytes32) { return _roles[role].adminRole; } /** * @dev Grants `role` to `account`. * * If `account` had not been already granted `role`, emits a {RoleGranted} * event. * * Requirements: * * - the caller must have ``role``'s admin role. */ function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) { _grantRole(role, account); } /** * @dev Revokes `role` from `account`. * * If `account` had been granted `role`, emits a {RoleRevoked} event. * * Requirements: * * - the caller must have ``role``'s admin role. */ function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) { _revokeRole(role, account); } /** * @dev Revokes `role` from the calling account. * * Roles are often managed via {grantRole} and {revokeRole}: this function's * purpose is to provide a mechanism for accounts to lose their privileges * if they are compromised (such as when a trusted device is misplaced). * * If the calling account had been granted `role`, emits a {RoleRevoked} * event. * * Requirements: * * - the caller must be `account`. */ function renounceRole(bytes32 role, address account) public virtual override { require(account == _msgSender(), "AccessControl: can only renounce roles for self"); _revokeRole(role, account); } /** * @dev Grants `role` to `account`. * * If `account` had not been already granted `role`, emits a {RoleGranted} * event. Note that unlike {grantRole}, this function doesn't perform any * checks on the calling account. * * [WARNING] * ==== * This function should only be called from the constructor when setting * up the initial roles for the system. * * Using this function in any other way is effectively circumventing the admin * system imposed by {AccessControl}. * ==== */ function _setupRole(bytes32 role, address account) internal virtual { _grantRole(role, account); } /** * @dev Sets `adminRole` as ``role``'s admin role. * * Emits a {RoleAdminChanged} event. */ function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual { emit RoleAdminChanged(role, getRoleAdmin(role), adminRole); _roles[role].adminRole = adminRole; } function _grantRole(bytes32 role, address account) private { if (!hasRole(role, account)) { _roles[role].members[account] = true; emit RoleGranted(role, account, _msgSender()); } } function _revokeRole(bytes32 role, address account) private { if (hasRole(role, account)) { _roles[role].members[account] = false; emit RoleRevoked(role, account, _msgSender()); } } } // SPDX-License-Identifier: MIT 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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin guidelines: functions revert instead * of 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 defaut 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: * * - `recipient` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address recipient, uint256 amount) public virtual override returns (bool) { _transfer(_msgSender(), recipient, 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}. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { _approve(_msgSender(), 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}. * * Requirements: * * - `sender` and `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. * - the caller must have allowance for ``sender``'s tokens of at least * `amount`. */ function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) { _transfer(sender, recipient, amount); uint256 currentAllowance = _allowances[sender][_msgSender()]; require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance"); _approve(sender, _msgSender(), currentAllowance - 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) { _approve(_msgSender(), spender, _allowances[_msgSender()][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) { uint256 currentAllowance = _allowances[_msgSender()][spender]; require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); _approve(_msgSender(), spender, currentAllowance - subtractedValue); return true; } /** * @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` cannot be the zero address. * - `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. */ function _transfer(address sender, address recipient, uint256 amount) internal virtual { require(sender != address(0), "ERC20: transfer from the zero address"); require(recipient != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(sender, recipient, amount); uint256 senderBalance = _balances[sender]; require(senderBalance >= amount, "ERC20: transfer amount exceeds balance"); _balances[sender] = senderBalance - amount; _balances[recipient] += amount; emit Transfer(sender, recipient, 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: * * - `to` 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); } /** * @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"); _balances[account] = accountBalance - amount; _totalSupply -= amount; emit Transfer(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 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 to 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 { } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @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 `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 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 `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); } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../ERC20.sol"; import "../../../utils/Context.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 * 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 { uint256 currentAllowance = allowance(account, _msgSender()); require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance"); _approve(account, _msgSender(), currentAllowance - amount); _burn(account, amount); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../ERC20.sol"; /** * @dev Extension of {ERC20} that adds a cap to the supply of tokens. */ abstract contract ERC20Capped is ERC20 { uint256 immutable private _cap; /** * @dev Sets the value of the `cap`. This value is immutable, it can only be * set once during construction. */ constructor (uint256 cap_) { require(cap_ > 0, "ERC20Capped: cap is 0"); _cap = cap_; } /** * @dev Returns the cap on the token's total supply. */ function cap() public view virtual returns (uint256) { return _cap; } /** * @dev See {ERC20-_mint}. */ function _mint(address account, uint256 amount) internal virtual override { require(ERC20.totalSupply() + amount <= cap(), "ERC20Capped: cap exceeded"); super._mint(account, amount); } } // SPDX-License-Identifier: MIT 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); } // SPDX-License-Identifier: MIT 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) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev String operations. */ library Strings { bytes16 private constant alphabet = "0123456789abcdef"; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { // Inspired by OraclizeAPI's implementation - MIT licence // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol if (value == 0) { return "0"; } uint256 temp = value; uint256 digits; while (temp != 0) { digits++; temp /= 10; } bytes memory buffer = new bytes(digits); while (value != 0) { digits -= 1; buffer[digits] = bytes1(uint8(48 + uint256(value % 10))); value /= 10; } return string(buffer); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { if (value == 0) { return "0x00"; } uint256 temp = value; uint256 length = 0; while (temp != 0) { length++; temp >>= 8; } return toHexString(value, length); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = alphabet[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "./IERC165.sol"; /** * @dev Implementation of the {IERC165} interface. * * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check * for the additional interface id that will be supported. For example: * * ```solidity * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId); * } * ``` * * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation. */ abstract contract ERC165 is IERC165 { /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IERC165).interfaceId; } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); }