{ "language": "Solidity", "sources": { "contracts/TaiChiPandas.sol": { "content": "// SPDX-License-Identifier: MIT\n\n// Freelance Developer ==> http://twitter.com/FudMonk\n\npragma solidity >=0.8.9 <0.9.0;\n\nimport \"erc721a/contracts/extensions/ERC721AQueryable.sol\";\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\nimport \"@openzeppelin/contracts/finance/PaymentSplitter.sol\";\nimport \"@openzeppelin/contracts/utils/cryptography/MerkleProof.sol\";\nimport \"@openzeppelin/contracts/security/ReentrancyGuard.sol\";\n\ncontract TaiChiPandas is\n ERC721AQueryable,\n PaymentSplitter,\n Ownable,\n ReentrancyGuard\n{\n using Strings for uint256;\n\n uint256 public teamReserve;\n\n bytes32 public merkleRoot;\n\n bytes32 public freemerkleRoot;\n uint256 public freeMinted;\n mapping(address => bool) public freelistClaimed;\n\n string public uriPrefix = \"\";\n string public uriSuffix = \".json\";\n string public hiddenMetadataUri;\n\n uint256 public cost;\n uint256 public maxSupply;\n uint256 public freeSupply;\n uint256 public maxMintAmountPerTx;\n\n uint256 private payeeLength;\n\n bool public paused = true;\n bool public whitelistMintEnabled = false;\n bool public freelistMintEnabled = false;\n bool public reserved = true;\n bool public revealed = false;\n\n constructor(\n string memory _tokenName,\n string memory _tokenSymbol,\n uint256 _cost,\n uint256 _maxSupply,\n uint256 _freeSupply,\n uint256 _teamReserve,\n address[] memory _payee,\n uint256[] memory _shares,\n uint256 _maxMintAmountPerTx,\n string memory _hiddenMetadataUri\n ) ERC721A(_tokenName, _tokenSymbol) PaymentSplitter(_payee, _shares) {\n setCost(_cost);\n maxSupply = _maxSupply;\n freeSupply = _freeSupply;\n teamReserve = _teamReserve;\n payeeLength = _payee.length;\n setMaxMintAmountPerTx(_maxMintAmountPerTx);\n setHiddenMetadataUri(_hiddenMetadataUri);\n _safeMint(_msgSender(), _teamReserve);\n freeMinted = 0;\n }\n\n modifier mintCompliance(uint256 _mintAmount) {\n require(\n _mintAmount > 0 && _mintAmount <= maxMintAmountPerTx,\n \"Invalid mint amount!\"\n );\n if (reserved) {\n require(\n totalSupply() + _mintAmount <= maxSupply - freeSupply,\n \"Reserved\"\n );\n } else {\n require(\n totalSupply() + _mintAmount <= maxSupply,\n \"Max supply exceeded!\"\n );\n }\n _;\n }\n\n modifier freeCompliance(uint256 _mintAmount) {\n require(\n _mintAmount > 0 && _mintAmount <= maxMintAmountPerTx,\n \"Invalid mint amount!\"\n );\n require(\n freeMinted + _mintAmount <= freeSupply,\n \"Free supply exceeded!\"\n );\n require(\n totalSupply() + _mintAmount <= maxSupply,\n \"Max supply exceeded!\"\n );\n _;\n }\n\n modifier mintPriceCompliance(uint256 _mintAmount) {\n require(msg.value >= cost * _mintAmount, \"Insufficient funds!\");\n _;\n }\n\n function whitelistMint(uint256 _mintAmount, bytes32[] calldata _merkleProof)\n public\n payable\n mintCompliance(_mintAmount)\n mintPriceCompliance(_mintAmount)\n {\n // Verify whitelist requirements\n require(whitelistMintEnabled, \"The whitelist sale is not enabled!\");\n bytes32 leaf = keccak256(abi.encodePacked(_msgSender()));\n require(\n MerkleProof.verify(_merkleProof, merkleRoot, leaf),\n \"Invalid proof!\"\n );\n\n _safeMint(_msgSender(), _mintAmount);\n }\n\n\n function freelistMint(uint256 _mintAmount, bytes32[] calldata _merkleProof)\n public\n payable\n freeCompliance(_mintAmount)\n {\n // Verify whitelist requirements\n require(freelistMintEnabled, \"The freelist sale is not enabled!\");\n require(!freelistClaimed[_msgSender()], \"Address already claimed!\");\n bytes32 leaf = keccak256(abi.encodePacked(_msgSender()));\n require(\n MerkleProof.verify(_merkleProof, freemerkleRoot, leaf),\n \"Invalid proof!\"\n );\n\n freeMinted += _mintAmount;\n freelistClaimed[_msgSender()] = true;\n _safeMint(_msgSender(), _mintAmount);\n }\n\n function mint(uint256 _mintAmount)\n public\n payable\n mintCompliance(_mintAmount)\n mintPriceCompliance(_mintAmount)\n {\n require(!paused, \"The contract is paused!\");\n\n _safeMint(_msgSender(), _mintAmount);\n }\n\n function mintForAddress(uint256 _mintAmount, address _receiver)\n public\n mintCompliance(_mintAmount)\n onlyOwner\n {\n _safeMint(_receiver, _mintAmount);\n }\n\n function _startTokenId() internal view virtual override returns (uint256) {\n return 1;\n }\n\n function tokenURI(uint256 _tokenId)\n public\n view\n virtual\n override\n returns (string memory)\n {\n require(\n _exists(_tokenId),\n \"ERC721Metadata: URI query for nonexistent token\"\n );\n\n if (revealed == false) {\n return hiddenMetadataUri;\n }\n\n string memory currentBaseURI = _baseURI();\n return\n bytes(currentBaseURI).length > 0\n ? string(\n abi.encodePacked(\n currentBaseURI,\n _tokenId.toString(),\n uriSuffix\n )\n )\n : \"\";\n }\n\n function setRevealed(bool _state) public onlyOwner {\n revealed = _state;\n }\n\n function setCost(uint256 _cost) public onlyOwner {\n cost = _cost;\n }\n\n function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx)\n public\n onlyOwner\n {\n maxMintAmountPerTx = _maxMintAmountPerTx;\n }\n\n function setHiddenMetadataUri(string memory _hiddenMetadataUri)\n public\n onlyOwner\n {\n hiddenMetadataUri = _hiddenMetadataUri;\n }\n\n function setUriPrefix(string memory _uriPrefix) public onlyOwner {\n uriPrefix = _uriPrefix;\n }\n\n function setUriSuffix(string memory _uriSuffix) public onlyOwner {\n uriSuffix = _uriSuffix;\n }\n\n function setPaused(bool _state) public onlyOwner {\n paused = _state;\n }\n\n function setReserved() public onlyOwner {\n reserved = !reserved;\n }\n\n function setMerkleRoot(bytes32 _merkleRoot) public onlyOwner {\n merkleRoot = _merkleRoot;\n }\n\n function setfreeMerkleRoot(bytes32 _merkleRoot) public onlyOwner {\n freemerkleRoot = _merkleRoot;\n }\n\n function setWhitelistMintEnabled(bool _state) public onlyOwner {\n whitelistMintEnabled = _state;\n }\n\n function setfreelistMintEnabled(bool _state) public onlyOwner {\n freelistMintEnabled = _state;\n }\n\n function releaseAll() external onlyOwner {\n for (uint256 i = 0; i < payeeLength; i++) {\n release(payable(payee(i)));\n }\n }\n\n function _baseURI() internal view virtual override returns (string memory) {\n return uriPrefix;\n }\n}\n" }, "erc721a/contracts/extensions/ERC721AQueryable.sol": { "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v3.3.0\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport './IERC721AQueryable.sol';\nimport '../ERC721A.sol';\n\n/**\n * @title ERC721A Queryable\n * @dev ERC721A subclass with convenience query functions.\n */\nabstract contract ERC721AQueryable is ERC721A, IERC721AQueryable {\n /**\n * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.\n *\n * If the `tokenId` is out of bounds:\n * - `addr` = `address(0)`\n * - `startTimestamp` = `0`\n * - `burned` = `false`\n *\n * If the `tokenId` is burned:\n * - `addr` = `
`\n * - `startTimestamp` = ``\n * - `burned = `true`\n *\n * Otherwise:\n * - `addr` = `
`\n * - `startTimestamp` = ``\n * - `burned = `false`\n */\n function explicitOwnershipOf(uint256 tokenId) public view override returns (TokenOwnership memory) {\n TokenOwnership memory ownership;\n if (tokenId < _startTokenId() || tokenId >= _currentIndex) {\n return ownership;\n }\n ownership = _ownerships[tokenId];\n if (ownership.burned) {\n return ownership;\n }\n return _ownershipOf(tokenId);\n }\n\n /**\n * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.\n * See {ERC721AQueryable-explicitOwnershipOf}\n */\n function explicitOwnershipsOf(uint256[] memory tokenIds) external view override returns (TokenOwnership[] memory) {\n unchecked {\n uint256 tokenIdsLength = tokenIds.length;\n TokenOwnership[] memory ownerships = new TokenOwnership[](tokenIdsLength);\n for (uint256 i; i != tokenIdsLength; ++i) {\n ownerships[i] = explicitOwnershipOf(tokenIds[i]);\n }\n return ownerships;\n }\n }\n\n /**\n * @dev Returns an array of token IDs owned by `owner`,\n * in the range [`start`, `stop`)\n * (i.e. `start <= tokenId < stop`).\n *\n * This function allows for tokens to be queried if the collection\n * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.\n *\n * Requirements:\n *\n * - `start` < `stop`\n */\n function tokensOfOwnerIn(\n address owner,\n uint256 start,\n uint256 stop\n ) external view override returns (uint256[] memory) {\n unchecked {\n if (start >= stop) revert InvalidQueryRange();\n uint256 tokenIdsIdx;\n uint256 stopLimit = _currentIndex;\n // Set `start = max(start, _startTokenId())`.\n if (start < _startTokenId()) {\n start = _startTokenId();\n }\n // Set `stop = min(stop, _currentIndex)`.\n if (stop > stopLimit) {\n stop = stopLimit;\n }\n uint256 tokenIdsMaxLength = balanceOf(owner);\n // Set `tokenIdsMaxLength = min(balanceOf(owner), stop - start)`,\n // to cater for cases where `balanceOf(owner)` is too big.\n if (start < stop) {\n uint256 rangeLength = stop - start;\n if (rangeLength < tokenIdsMaxLength) {\n tokenIdsMaxLength = rangeLength;\n }\n } else {\n tokenIdsMaxLength = 0;\n }\n uint256[] memory tokenIds = new uint256[](tokenIdsMaxLength);\n if (tokenIdsMaxLength == 0) {\n return tokenIds;\n }\n // We need to call `explicitOwnershipOf(start)`,\n // because the slot at `start` may not be initialized.\n TokenOwnership memory ownership = explicitOwnershipOf(start);\n address currOwnershipAddr;\n // If the starting slot exists (i.e. not burned), initialize `currOwnershipAddr`.\n // `ownership.address` will not be zero, as `start` is clamped to the valid token ID range.\n if (!ownership.burned) {\n currOwnershipAddr = ownership.addr;\n }\n for (uint256 i = start; i != stop && tokenIdsIdx != tokenIdsMaxLength; ++i) {\n ownership = _ownerships[i];\n if (ownership.burned) {\n continue;\n }\n if (ownership.addr != address(0)) {\n currOwnershipAddr = ownership.addr;\n }\n if (currOwnershipAddr == owner) {\n tokenIds[tokenIdsIdx++] = i;\n }\n }\n // Downsize the array to fit.\n assembly {\n mstore(tokenIds, tokenIdsIdx)\n }\n return tokenIds;\n }\n }\n\n /**\n * @dev Returns an array of token IDs owned by `owner`.\n *\n * This function scans the ownership mapping and is O(totalSupply) in complexity.\n * It is meant to be called off-chain.\n *\n * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into\n * multiple smaller scans if the collection is large enough to cause\n * an out-of-gas error (10K pfp collections should be fine).\n */\n function tokensOfOwner(address owner) external view override returns (uint256[] memory) {\n unchecked {\n uint256 tokenIdsIdx;\n address currOwnershipAddr;\n uint256 tokenIdsLength = balanceOf(owner);\n uint256[] memory tokenIds = new uint256[](tokenIdsLength);\n TokenOwnership memory ownership;\n for (uint256 i = _startTokenId(); tokenIdsIdx != tokenIdsLength; ++i) {\n ownership = _ownerships[i];\n if (ownership.burned) {\n continue;\n }\n if (ownership.addr != address(0)) {\n currOwnershipAddr = ownership.addr;\n }\n if (currOwnershipAddr == owner) {\n tokenIds[tokenIdsIdx++] = i;\n }\n }\n return tokenIds;\n }\n }\n}\n" }, "@openzeppelin/contracts/access/Ownable.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n address private _owner;\n\n event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n /**\n * @dev Initializes the contract setting the deployer as the initial owner.\n */\n constructor() {\n _transferOwnership(_msgSender());\n }\n\n /**\n * @dev Returns the address of the current owner.\n */\n function owner() public view virtual returns (address) {\n return _owner;\n }\n\n /**\n * @dev Throws if called by any account other than the owner.\n */\n modifier onlyOwner() {\n require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n _;\n }\n\n /**\n * @dev Leaves the contract without owner. It will not be possible to call\n * `onlyOwner` functions anymore. Can only be called by the current owner.\n *\n * NOTE: Renouncing ownership will leave the contract without an owner,\n * thereby removing any functionality that is only available to the owner.\n */\n function renounceOwnership() public virtual onlyOwner {\n _transferOwnership(address(0));\n }\n\n /**\n * @dev Transfers ownership of the contract to a new account (`newOwner`).\n * Can only be called by the current owner.\n */\n function transferOwnership(address newOwner) public virtual onlyOwner {\n require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n _transferOwnership(newOwner);\n }\n\n /**\n * @dev Transfers ownership of the contract to a new account (`newOwner`).\n * Internal function without access restriction.\n */\n function _transferOwnership(address newOwner) internal virtual {\n address oldOwner = _owner;\n _owner = newOwner;\n emit OwnershipTransferred(oldOwner, newOwner);\n }\n}\n" }, "@openzeppelin/contracts/finance/PaymentSplitter.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (finance/PaymentSplitter.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../token/ERC20/utils/SafeERC20.sol\";\nimport \"../utils/Address.sol\";\nimport \"../utils/Context.sol\";\n\n/**\n * @title PaymentSplitter\n * @dev This contract allows to split Ether payments among a group of accounts. The sender does not need to be aware\n * that the Ether will be split in this way, since it is handled transparently by the contract.\n *\n * The split can be in equal parts or in any other arbitrary proportion. The way this is specified is by assigning each\n * account to a number of shares. Of all the Ether that this contract receives, each account will then be able to claim\n * an amount proportional to the percentage of total shares they were assigned.\n *\n * `PaymentSplitter` follows a _pull payment_ model. This means that payments are not automatically forwarded to the\n * accounts but kept in this contract, and the actual transfer is triggered as a separate step by calling the {release}\n * function.\n *\n * NOTE: This contract assumes that ERC20 tokens will behave similarly to native tokens (Ether). Rebasing tokens, and\n * tokens that apply fees during transfers, are likely to not be supported as expected. If in doubt, we encourage you\n * to run tests before sending real value to this contract.\n */\ncontract PaymentSplitter is Context {\n event PayeeAdded(address account, uint256 shares);\n event PaymentReleased(address to, uint256 amount);\n event ERC20PaymentReleased(IERC20 indexed token, address to, uint256 amount);\n event PaymentReceived(address from, uint256 amount);\n\n uint256 private _totalShares;\n uint256 private _totalReleased;\n\n mapping(address => uint256) private _shares;\n mapping(address => uint256) private _released;\n address[] private _payees;\n\n mapping(IERC20 => uint256) private _erc20TotalReleased;\n mapping(IERC20 => mapping(address => uint256)) private _erc20Released;\n\n /**\n * @dev Creates an instance of `PaymentSplitter` where each account in `payees` is assigned the number of shares at\n * the matching position in the `shares` array.\n *\n * All addresses in `payees` must be non-zero. Both arrays must have the same non-zero length, and there must be no\n * duplicates in `payees`.\n */\n constructor(address[] memory payees, uint256[] memory shares_) payable {\n require(payees.length == shares_.length, \"PaymentSplitter: payees and shares length mismatch\");\n require(payees.length > 0, \"PaymentSplitter: no payees\");\n\n for (uint256 i = 0; i < payees.length; i++) {\n _addPayee(payees[i], shares_[i]);\n }\n }\n\n /**\n * @dev The Ether received will be logged with {PaymentReceived} events. Note that these events are not fully\n * reliable: it's possible for a contract to receive Ether without triggering this function. This only affects the\n * reliability of the events, and not the actual splitting of Ether.\n *\n * To learn more about this see the Solidity documentation for\n * https://solidity.readthedocs.io/en/latest/contracts.html#fallback-function[fallback\n * functions].\n */\n receive() external payable virtual {\n emit PaymentReceived(_msgSender(), msg.value);\n }\n\n /**\n * @dev Getter for the total shares held by payees.\n */\n function totalShares() public view returns (uint256) {\n return _totalShares;\n }\n\n /**\n * @dev Getter for the total amount of Ether already released.\n */\n function totalReleased() public view returns (uint256) {\n return _totalReleased;\n }\n\n /**\n * @dev Getter for the total amount of `token` already released. `token` should be the address of an IERC20\n * contract.\n */\n function totalReleased(IERC20 token) public view returns (uint256) {\n return _erc20TotalReleased[token];\n }\n\n /**\n * @dev Getter for the amount of shares held by an account.\n */\n function shares(address account) public view returns (uint256) {\n return _shares[account];\n }\n\n /**\n * @dev Getter for the amount of Ether already released to a payee.\n */\n function released(address account) public view returns (uint256) {\n return _released[account];\n }\n\n /**\n * @dev Getter for the amount of `token` tokens already released to a payee. `token` should be the address of an\n * IERC20 contract.\n */\n function released(IERC20 token, address account) public view returns (uint256) {\n return _erc20Released[token][account];\n }\n\n /**\n * @dev Getter for the address of the payee number `index`.\n */\n function payee(uint256 index) public view returns (address) {\n return _payees[index];\n }\n\n /**\n * @dev Triggers a transfer to `account` of the amount of Ether they are owed, according to their percentage of the\n * total shares and their previous withdrawals.\n */\n function release(address payable account) public virtual {\n require(_shares[account] > 0, \"PaymentSplitter: account has no shares\");\n\n uint256 totalReceived = address(this).balance + totalReleased();\n uint256 payment = _pendingPayment(account, totalReceived, released(account));\n\n require(payment != 0, \"PaymentSplitter: account is not due payment\");\n\n _released[account] += payment;\n _totalReleased += payment;\n\n Address.sendValue(account, payment);\n emit PaymentReleased(account, payment);\n }\n\n /**\n * @dev Triggers a transfer to `account` of the amount of `token` tokens they are owed, according to their\n * percentage of the total shares and their previous withdrawals. `token` must be the address of an IERC20\n * contract.\n */\n function release(IERC20 token, address account) public virtual {\n require(_shares[account] > 0, \"PaymentSplitter: account has no shares\");\n\n uint256 totalReceived = token.balanceOf(address(this)) + totalReleased(token);\n uint256 payment = _pendingPayment(account, totalReceived, released(token, account));\n\n require(payment != 0, \"PaymentSplitter: account is not due payment\");\n\n _erc20Released[token][account] += payment;\n _erc20TotalReleased[token] += payment;\n\n SafeERC20.safeTransfer(token, account, payment);\n emit ERC20PaymentReleased(token, account, payment);\n }\n\n /**\n * @dev internal logic for computing the pending payment of an `account` given the token historical balances and\n * already released amounts.\n */\n function _pendingPayment(\n address account,\n uint256 totalReceived,\n uint256 alreadyReleased\n ) private view returns (uint256) {\n return (totalReceived * _shares[account]) / _totalShares - alreadyReleased;\n }\n\n /**\n * @dev Add a new payee to the contract.\n * @param account The address of the payee to add.\n * @param shares_ The number of shares owned by the payee.\n */\n function _addPayee(address account, uint256 shares_) private {\n require(account != address(0), \"PaymentSplitter: account is the zero address\");\n require(shares_ > 0, \"PaymentSplitter: shares are 0\");\n require(_shares[account] == 0, \"PaymentSplitter: account already has shares\");\n\n _payees.push(account);\n _shares[account] = shares_;\n _totalShares = _totalShares + shares_;\n emit PayeeAdded(account, shares_);\n }\n}\n" }, "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev These functions deal with verification of Merkle Trees proofs.\n *\n * The proofs can be generated using the JavaScript library\n * https://github.com/miguelmota/merkletreejs[merkletreejs].\n * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.\n *\n * See `test/utils/cryptography/MerkleProof.test.js` for some examples.\n */\nlibrary MerkleProof {\n /**\n * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree\n * defined by `root`. For this, a `proof` must be provided, containing\n * sibling hashes on the branch from the leaf to the root of the tree. Each\n * pair of leaves and each pair of pre-images are assumed to be sorted.\n */\n function verify(\n bytes32[] memory proof,\n bytes32 root,\n bytes32 leaf\n ) internal pure returns (bool) {\n return processProof(proof, leaf) == root;\n }\n\n /**\n * @dev Returns the rebuilt hash obtained by traversing a Merklee tree up\n * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt\n * hash matches the root of the tree. When processing the proof, the pairs\n * of leafs & pre-images are assumed to be sorted.\n *\n * _Available since v4.4._\n */\n function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {\n bytes32 computedHash = leaf;\n for (uint256 i = 0; i < proof.length; i++) {\n bytes32 proofElement = proof[i];\n if (computedHash <= proofElement) {\n // Hash(current computed hash + current element of the proof)\n computedHash = _efficientHash(computedHash, proofElement);\n } else {\n // Hash(current element of the proof + current computed hash)\n computedHash = _efficientHash(proofElement, computedHash);\n }\n }\n return computedHash;\n }\n\n function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {\n assembly {\n mstore(0x00, a)\n mstore(0x20, b)\n value := keccak256(0x00, 0x40)\n }\n }\n}\n" }, "@openzeppelin/contracts/security/ReentrancyGuard.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Contract module that helps prevent reentrant calls to a function.\n *\n * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier\n * available, which can be applied to functions to make sure there are no nested\n * (reentrant) calls to them.\n *\n * Note that because there is a single `nonReentrant` guard, functions marked as\n * `nonReentrant` may not call one another. This can be worked around by making\n * those functions `private`, and then adding `external` `nonReentrant` entry\n * points to them.\n *\n * TIP: If you would like to learn more about reentrancy and alternative ways\n * to protect against it, check out our blog post\n * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].\n */\nabstract contract ReentrancyGuard {\n // Booleans are more expensive than uint256 or any type that takes up a full\n // word because each write operation emits an extra SLOAD to first read the\n // slot's contents, replace the bits taken up by the boolean, and then write\n // back. This is the compiler's defense against contract upgrades and\n // pointer aliasing, and it cannot be disabled.\n\n // The values being non-zero value makes deployment a bit more expensive,\n // but in exchange the refund on every call to nonReentrant will be lower in\n // amount. Since refunds are capped to a percentage of the total\n // transaction's gas, it is best to keep them low in cases like this one, to\n // increase the likelihood of the full refund coming into effect.\n uint256 private constant _NOT_ENTERED = 1;\n uint256 private constant _ENTERED = 2;\n\n uint256 private _status;\n\n constructor() {\n _status = _NOT_ENTERED;\n }\n\n /**\n * @dev Prevents a contract from calling itself, directly or indirectly.\n * Calling a `nonReentrant` function from another `nonReentrant`\n * function is not supported. It is possible to prevent this from happening\n * by making the `nonReentrant` function external, and making it call a\n * `private` function that does the actual work.\n */\n modifier nonReentrant() {\n // On the first call to nonReentrant, _notEntered will be true\n require(_status != _ENTERED, \"ReentrancyGuard: reentrant call\");\n\n // Any calls to nonReentrant after this point will fail\n _status = _ENTERED;\n\n _;\n\n // By storing the original value once again, a refund is triggered (see\n // https://eips.ethereum.org/EIPS/eip-2200)\n _status = _NOT_ENTERED;\n }\n}\n" }, "erc721a/contracts/extensions/IERC721AQueryable.sol": { "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v3.3.0\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport '../IERC721A.sol';\n\n/**\n * @dev Interface of an ERC721AQueryable compliant contract.\n */\ninterface IERC721AQueryable is IERC721A {\n /**\n * Invalid query range (`start` >= `stop`).\n */\n error InvalidQueryRange();\n\n /**\n * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.\n *\n * If the `tokenId` is out of bounds:\n * - `addr` = `address(0)`\n * - `startTimestamp` = `0`\n * - `burned` = `false`\n *\n * If the `tokenId` is burned:\n * - `addr` = `
`\n * - `startTimestamp` = ``\n * - `burned = `true`\n *\n * Otherwise:\n * - `addr` = `
`\n * - `startTimestamp` = ``\n * - `burned = `false`\n */\n function explicitOwnershipOf(uint256 tokenId) external view returns (TokenOwnership memory);\n\n /**\n * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.\n * See {ERC721AQueryable-explicitOwnershipOf}\n */\n function explicitOwnershipsOf(uint256[] memory tokenIds) external view returns (TokenOwnership[] memory);\n\n /**\n * @dev Returns an array of token IDs owned by `owner`,\n * in the range [`start`, `stop`)\n * (i.e. `start <= tokenId < stop`).\n *\n * This function allows for tokens to be queried if the collection\n * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.\n *\n * Requirements:\n *\n * - `start` < `stop`\n */\n function tokensOfOwnerIn(\n address owner,\n uint256 start,\n uint256 stop\n ) external view returns (uint256[] memory);\n\n /**\n * @dev Returns an array of token IDs owned by `owner`.\n *\n * This function scans the ownership mapping and is O(totalSupply) in complexity.\n * It is meant to be called off-chain.\n *\n * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into\n * multiple smaller scans if the collection is large enough to cause\n * an out-of-gas error (10K pfp collections should be fine).\n */\n function tokensOfOwner(address owner) external view returns (uint256[] memory);\n}\n" }, "erc721a/contracts/ERC721A.sol": { "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v3.3.0\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport './IERC721A.sol';\nimport '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';\nimport '@openzeppelin/contracts/utils/Address.sol';\nimport '@openzeppelin/contracts/utils/Context.sol';\nimport '@openzeppelin/contracts/utils/Strings.sol';\nimport '@openzeppelin/contracts/utils/introspection/ERC165.sol';\n\n/**\n * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including\n * the Metadata extension. Built to optimize for lower gas during batch mints.\n *\n * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).\n *\n * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.\n *\n * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).\n */\ncontract ERC721A is Context, ERC165, IERC721A {\n using Address for address;\n using Strings for uint256;\n\n // The tokenId of the next token to be minted.\n uint256 internal _currentIndex;\n\n // The number of tokens burned.\n uint256 internal _burnCounter;\n\n // Token name\n string private _name;\n\n // Token symbol\n string private _symbol;\n\n // Mapping from token ID to ownership details\n // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.\n mapping(uint256 => TokenOwnership) internal _ownerships;\n\n // Mapping owner address to address data\n mapping(address => AddressData) private _addressData;\n\n // Mapping from token ID to approved address\n mapping(uint256 => address) private _tokenApprovals;\n\n // Mapping from owner to operator approvals\n mapping(address => mapping(address => bool)) private _operatorApprovals;\n\n constructor(string memory name_, string memory symbol_) {\n _name = name_;\n _symbol = symbol_;\n _currentIndex = _startTokenId();\n }\n\n /**\n * To change the starting tokenId, please override this function.\n */\n function _startTokenId() internal view virtual returns (uint256) {\n return 0;\n }\n\n /**\n * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.\n */\n function totalSupply() public view override returns (uint256) {\n // Counter underflow is impossible as _burnCounter cannot be incremented\n // more than _currentIndex - _startTokenId() times\n unchecked {\n return _currentIndex - _burnCounter - _startTokenId();\n }\n }\n\n /**\n * Returns the total amount of tokens minted in the contract.\n */\n function _totalMinted() internal view returns (uint256) {\n // Counter underflow is impossible as _currentIndex does not decrement,\n // and it is initialized to _startTokenId()\n unchecked {\n return _currentIndex - _startTokenId();\n }\n }\n\n /**\n * @dev See {IERC165-supportsInterface}.\n */\n function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {\n return\n interfaceId == type(IERC721).interfaceId ||\n interfaceId == type(IERC721Metadata).interfaceId ||\n super.supportsInterface(interfaceId);\n }\n\n /**\n * @dev See {IERC721-balanceOf}.\n */\n function balanceOf(address owner) public view override returns (uint256) {\n if (owner == address(0)) revert BalanceQueryForZeroAddress();\n return uint256(_addressData[owner].balance);\n }\n\n /**\n * Returns the number of tokens minted by `owner`.\n */\n function _numberMinted(address owner) internal view returns (uint256) {\n return uint256(_addressData[owner].numberMinted);\n }\n\n /**\n * Returns the number of tokens burned by or on behalf of `owner`.\n */\n function _numberBurned(address owner) internal view returns (uint256) {\n return uint256(_addressData[owner].numberBurned);\n }\n\n /**\n * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).\n */\n function _getAux(address owner) internal view returns (uint64) {\n return _addressData[owner].aux;\n }\n\n /**\n * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).\n * If there are multiple variables, please pack them into a uint64.\n */\n function _setAux(address owner, uint64 aux) internal {\n _addressData[owner].aux = aux;\n }\n\n /**\n * Gas spent here starts off proportional to the maximum mint batch size.\n * It gradually moves to O(1) as tokens get transferred around in the collection over time.\n */\n function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {\n uint256 curr = tokenId;\n\n unchecked {\n if (_startTokenId() <= curr) if (curr < _currentIndex) {\n TokenOwnership memory ownership = _ownerships[curr];\n if (!ownership.burned) {\n if (ownership.addr != address(0)) {\n return ownership;\n }\n // Invariant:\n // There will always be an ownership that has an address and is not burned\n // before an ownership that does not have an address and is not burned.\n // Hence, curr will not underflow.\n while (true) {\n curr--;\n ownership = _ownerships[curr];\n if (ownership.addr != address(0)) {\n return ownership;\n }\n }\n }\n }\n }\n revert OwnerQueryForNonexistentToken();\n }\n\n /**\n * @dev See {IERC721-ownerOf}.\n */\n function ownerOf(uint256 tokenId) public view override returns (address) {\n return _ownershipOf(tokenId).addr;\n }\n\n /**\n * @dev See {IERC721Metadata-name}.\n */\n function name() public view virtual override returns (string memory) {\n return _name;\n }\n\n /**\n * @dev See {IERC721Metadata-symbol}.\n */\n function symbol() public view virtual override returns (string memory) {\n return _symbol;\n }\n\n /**\n * @dev See {IERC721Metadata-tokenURI}.\n */\n function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {\n if (!_exists(tokenId)) revert URIQueryForNonexistentToken();\n\n string memory baseURI = _baseURI();\n return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';\n }\n\n /**\n * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each\n * token will be the concatenation of the `baseURI` and the `tokenId`. Empty\n * by default, can be overriden in child contracts.\n */\n function _baseURI() internal view virtual returns (string memory) {\n return '';\n }\n\n /**\n * @dev See {IERC721-approve}.\n */\n function approve(address to, uint256 tokenId) public override {\n address owner = ERC721A.ownerOf(tokenId);\n if (to == owner) revert ApprovalToCurrentOwner();\n\n if (_msgSender() != owner) if(!isApprovedForAll(owner, _msgSender())) {\n revert ApprovalCallerNotOwnerNorApproved();\n }\n\n _approve(to, tokenId, owner);\n }\n\n /**\n * @dev See {IERC721-getApproved}.\n */\n function getApproved(uint256 tokenId) public view override returns (address) {\n if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();\n\n return _tokenApprovals[tokenId];\n }\n\n /**\n * @dev See {IERC721-setApprovalForAll}.\n */\n function setApprovalForAll(address operator, bool approved) public virtual override {\n if (operator == _msgSender()) revert ApproveToCaller();\n\n _operatorApprovals[_msgSender()][operator] = approved;\n emit ApprovalForAll(_msgSender(), operator, approved);\n }\n\n /**\n * @dev See {IERC721-isApprovedForAll}.\n */\n function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {\n return _operatorApprovals[owner][operator];\n }\n\n /**\n * @dev See {IERC721-transferFrom}.\n */\n function transferFrom(\n address from,\n address to,\n uint256 tokenId\n ) public virtual override {\n _transfer(from, to, tokenId);\n }\n\n /**\n * @dev See {IERC721-safeTransferFrom}.\n */\n function safeTransferFrom(\n address from,\n address to,\n uint256 tokenId\n ) public virtual override {\n safeTransferFrom(from, to, tokenId, '');\n }\n\n /**\n * @dev See {IERC721-safeTransferFrom}.\n */\n function safeTransferFrom(\n address from,\n address to,\n uint256 tokenId,\n bytes memory _data\n ) public virtual override {\n _transfer(from, to, tokenId);\n if (to.isContract()) if(!_checkContractOnERC721Received(from, to, tokenId, _data)) {\n revert TransferToNonERC721ReceiverImplementer();\n }\n }\n\n /**\n * @dev Returns whether `tokenId` exists.\n *\n * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\n *\n * Tokens start existing when they are minted (`_mint`),\n */\n function _exists(uint256 tokenId) internal view returns (bool) {\n return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;\n }\n\n /**\n * @dev Equivalent to `_safeMint(to, quantity, '')`.\n */\n function _safeMint(address to, uint256 quantity) internal {\n _safeMint(to, quantity, '');\n }\n\n /**\n * @dev Safely mints `quantity` tokens and transfers them to `to`.\n *\n * Requirements:\n *\n * - If `to` refers to a smart contract, it must implement\n * {IERC721Receiver-onERC721Received}, which is called for each safe transfer.\n * - `quantity` must be greater than 0.\n *\n * Emits a {Transfer} event.\n */\n function _safeMint(\n address to,\n uint256 quantity,\n bytes memory _data\n ) internal {\n uint256 startTokenId = _currentIndex;\n if (to == address(0)) revert MintToZeroAddress();\n if (quantity == 0) revert MintZeroQuantity();\n\n _beforeTokenTransfers(address(0), to, startTokenId, quantity);\n\n // Overflows are incredibly unrealistic.\n // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1\n // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1\n unchecked {\n _addressData[to].balance += uint64(quantity);\n _addressData[to].numberMinted += uint64(quantity);\n\n _ownerships[startTokenId].addr = to;\n _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);\n\n uint256 updatedIndex = startTokenId;\n uint256 end = updatedIndex + quantity;\n\n if (to.isContract()) {\n do {\n emit Transfer(address(0), to, updatedIndex);\n if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {\n revert TransferToNonERC721ReceiverImplementer();\n }\n } while (updatedIndex < end);\n // Reentrancy protection\n if (_currentIndex != startTokenId) revert();\n } else {\n do {\n emit Transfer(address(0), to, updatedIndex++);\n } while (updatedIndex < end);\n }\n _currentIndex = updatedIndex;\n }\n _afterTokenTransfers(address(0), to, startTokenId, quantity);\n }\n\n /**\n * @dev Mints `quantity` tokens and transfers them to `to`.\n *\n * Requirements:\n *\n * - `to` cannot be the zero address.\n * - `quantity` must be greater than 0.\n *\n * Emits a {Transfer} event.\n */\n function _mint(address to, uint256 quantity) internal {\n uint256 startTokenId = _currentIndex;\n if (to == address(0)) revert MintToZeroAddress();\n if (quantity == 0) revert MintZeroQuantity();\n\n _beforeTokenTransfers(address(0), to, startTokenId, quantity);\n\n // Overflows are incredibly unrealistic.\n // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1\n // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1\n unchecked {\n _addressData[to].balance += uint64(quantity);\n _addressData[to].numberMinted += uint64(quantity);\n\n _ownerships[startTokenId].addr = to;\n _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);\n\n uint256 updatedIndex = startTokenId;\n uint256 end = updatedIndex + quantity;\n\n do {\n emit Transfer(address(0), to, updatedIndex++);\n } while (updatedIndex < end);\n\n _currentIndex = updatedIndex;\n }\n _afterTokenTransfers(address(0), to, startTokenId, quantity);\n }\n\n /**\n * @dev Transfers `tokenId` from `from` to `to`.\n *\n * Requirements:\n *\n * - `to` cannot be the zero address.\n * - `tokenId` token must be owned by `from`.\n *\n * Emits a {Transfer} event.\n */\n function _transfer(\n address from,\n address to,\n uint256 tokenId\n ) private {\n TokenOwnership memory prevOwnership = _ownershipOf(tokenId);\n\n if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();\n\n bool isApprovedOrOwner = (_msgSender() == from ||\n isApprovedForAll(from, _msgSender()) ||\n getApproved(tokenId) == _msgSender());\n\n if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();\n if (to == address(0)) revert TransferToZeroAddress();\n\n _beforeTokenTransfers(from, to, tokenId, 1);\n\n // Clear approvals from the previous owner\n _approve(address(0), tokenId, from);\n\n // Underflow of the sender's balance is impossible because we check for\n // ownership above and the recipient's balance can't realistically overflow.\n // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.\n unchecked {\n _addressData[from].balance -= 1;\n _addressData[to].balance += 1;\n\n TokenOwnership storage currSlot = _ownerships[tokenId];\n currSlot.addr = to;\n currSlot.startTimestamp = uint64(block.timestamp);\n\n // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.\n // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.\n uint256 nextTokenId = tokenId + 1;\n TokenOwnership storage nextSlot = _ownerships[nextTokenId];\n if (nextSlot.addr == address(0)) {\n // This will suffice for checking _exists(nextTokenId),\n // as a burned slot cannot contain the zero address.\n if (nextTokenId != _currentIndex) {\n nextSlot.addr = from;\n nextSlot.startTimestamp = prevOwnership.startTimestamp;\n }\n }\n }\n\n emit Transfer(from, to, tokenId);\n _afterTokenTransfers(from, to, tokenId, 1);\n }\n\n /**\n * @dev Equivalent to `_burn(tokenId, false)`.\n */\n function _burn(uint256 tokenId) internal virtual {\n _burn(tokenId, false);\n }\n\n /**\n * @dev Destroys `tokenId`.\n * The approval is cleared when the token is burned.\n *\n * Requirements:\n *\n * - `tokenId` must exist.\n *\n * Emits a {Transfer} event.\n */\n function _burn(uint256 tokenId, bool approvalCheck) internal virtual {\n TokenOwnership memory prevOwnership = _ownershipOf(tokenId);\n\n address from = prevOwnership.addr;\n\n if (approvalCheck) {\n bool isApprovedOrOwner = (_msgSender() == from ||\n isApprovedForAll(from, _msgSender()) ||\n getApproved(tokenId) == _msgSender());\n\n if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();\n }\n\n _beforeTokenTransfers(from, address(0), tokenId, 1);\n\n // Clear approvals from the previous owner\n _approve(address(0), tokenId, from);\n\n // Underflow of the sender's balance is impossible because we check for\n // ownership above and the recipient's balance can't realistically overflow.\n // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.\n unchecked {\n AddressData storage addressData = _addressData[from];\n addressData.balance -= 1;\n addressData.numberBurned += 1;\n\n // Keep track of who burned the token, and the timestamp of burning.\n TokenOwnership storage currSlot = _ownerships[tokenId];\n currSlot.addr = from;\n currSlot.startTimestamp = uint64(block.timestamp);\n currSlot.burned = true;\n\n // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.\n // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.\n uint256 nextTokenId = tokenId + 1;\n TokenOwnership storage nextSlot = _ownerships[nextTokenId];\n if (nextSlot.addr == address(0)) {\n // This will suffice for checking _exists(nextTokenId),\n // as a burned slot cannot contain the zero address.\n if (nextTokenId != _currentIndex) {\n nextSlot.addr = from;\n nextSlot.startTimestamp = prevOwnership.startTimestamp;\n }\n }\n }\n\n emit Transfer(from, address(0), tokenId);\n _afterTokenTransfers(from, address(0), tokenId, 1);\n\n // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.\n unchecked {\n _burnCounter++;\n }\n }\n\n /**\n * @dev Approve `to` to operate on `tokenId`\n *\n * Emits a {Approval} event.\n */\n function _approve(\n address to,\n uint256 tokenId,\n address owner\n ) private {\n _tokenApprovals[tokenId] = to;\n emit Approval(owner, to, tokenId);\n }\n\n /**\n * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.\n *\n * @param from address representing the previous owner of the given token ID\n * @param to target address that will receive the tokens\n * @param tokenId uint256 ID of the token to be transferred\n * @param _data bytes optional data to send along with the call\n * @return bool whether the call correctly returned the expected magic value\n */\n function _checkContractOnERC721Received(\n address from,\n address to,\n uint256 tokenId,\n bytes memory _data\n ) private returns (bool) {\n try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {\n return retval == IERC721Receiver(to).onERC721Received.selector;\n } catch (bytes memory reason) {\n if (reason.length == 0) {\n revert TransferToNonERC721ReceiverImplementer();\n } else {\n assembly {\n revert(add(32, reason), mload(reason))\n }\n }\n }\n }\n\n /**\n * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.\n * And also called before burning one token.\n *\n * startTokenId - the first token id to be transferred\n * quantity - the amount to be transferred\n *\n * Calling conditions:\n *\n * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be\n * transferred to `to`.\n * - When `from` is zero, `tokenId` will be minted for `to`.\n * - When `to` is zero, `tokenId` will be burned by `from`.\n * - `from` and `to` are never both zero.\n */\n function _beforeTokenTransfers(\n address from,\n address to,\n uint256 startTokenId,\n uint256 quantity\n ) internal virtual {}\n\n /**\n * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes\n * minting.\n * And also called after one token has been burned.\n *\n * startTokenId - the first token id to be transferred\n * quantity - the amount to be transferred\n *\n * Calling conditions:\n *\n * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been\n * transferred to `to`.\n * - When `from` is zero, `tokenId` has been minted for `to`.\n * - When `to` is zero, `tokenId` has been burned by `from`.\n * - `from` and `to` are never both zero.\n */\n function _afterTokenTransfers(\n address from,\n address to,\n uint256 startTokenId,\n uint256 quantity\n ) internal virtual {}\n}\n" }, "erc721a/contracts/IERC721A.sol": { "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v3.3.0\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport '@openzeppelin/contracts/token/ERC721/IERC721.sol';\nimport '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';\n\n/**\n * @dev Interface of an ERC721A compliant contract.\n */\ninterface IERC721A is IERC721, IERC721Metadata {\n /**\n * The caller must own the token or be an approved operator.\n */\n error ApprovalCallerNotOwnerNorApproved();\n\n /**\n * The token does not exist.\n */\n error ApprovalQueryForNonexistentToken();\n\n /**\n * The caller cannot approve to their own address.\n */\n error ApproveToCaller();\n\n /**\n * The caller cannot approve to the current owner.\n */\n error ApprovalToCurrentOwner();\n\n /**\n * Cannot query the balance for the zero address.\n */\n error BalanceQueryForZeroAddress();\n\n /**\n * Cannot mint to the zero address.\n */\n error MintToZeroAddress();\n\n /**\n * The quantity of tokens minted must be more than zero.\n */\n error MintZeroQuantity();\n\n /**\n * The token does not exist.\n */\n error OwnerQueryForNonexistentToken();\n\n /**\n * The caller must own the token or be an approved operator.\n */\n error TransferCallerNotOwnerNorApproved();\n\n /**\n * The token must be owned by `from`.\n */\n error TransferFromIncorrectOwner();\n\n /**\n * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.\n */\n error TransferToNonERC721ReceiverImplementer();\n\n /**\n * Cannot transfer to the zero address.\n */\n error TransferToZeroAddress();\n\n /**\n * The token does not exist.\n */\n error URIQueryForNonexistentToken();\n\n // Compiler will pack this into a single 256bit word.\n struct TokenOwnership {\n // The address of the owner.\n address addr;\n // Keeps track of the start time of ownership with minimal overhead for tokenomics.\n uint64 startTimestamp;\n // Whether the token has been burned.\n bool burned;\n }\n\n // Compiler will pack this into a single 256bit word.\n struct AddressData {\n // Realistically, 2**64-1 is more than enough.\n uint64 balance;\n // Keeps track of mint count with minimal overhead for tokenomics.\n uint64 numberMinted;\n // Keeps track of burn count with minimal overhead for tokenomics.\n uint64 numberBurned;\n // For miscellaneous variable(s) pertaining to the address\n // (e.g. number of whitelist mint slots used).\n // If there are multiple variables, please pack them into a uint64.\n uint64 aux;\n }\n\n /**\n * @dev Returns the total amount of tokens stored by the contract.\n * \n * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.\n */\n function totalSupply() external view returns (uint256);\n}\n" }, "@openzeppelin/contracts/token/ERC721/IERC721.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../../utils/introspection/IERC165.sol\";\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ninterface IERC721 is IERC165 {\n /**\n * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\n */\n event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n\n /**\n * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\n */\n event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n\n /**\n * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\n */\n event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n /**\n * @dev Returns the number of tokens in ``owner``'s account.\n */\n function balanceOf(address owner) external view returns (uint256 balance);\n\n /**\n * @dev Returns the owner of the `tokenId` token.\n *\n * Requirements:\n *\n * - `tokenId` must exist.\n */\n function ownerOf(uint256 tokenId) external view returns (address owner);\n\n /**\n * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\n * are aware of the ERC721 protocol to prevent tokens from being forever locked.\n *\n * Requirements:\n *\n * - `from` cannot be the zero address.\n * - `to` cannot be the zero address.\n * - `tokenId` token must exist and be owned by `from`.\n * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\n * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n *\n * Emits a {Transfer} event.\n */\n function safeTransferFrom(\n address from,\n address to,\n uint256 tokenId\n ) external;\n\n /**\n * @dev Transfers `tokenId` token from `from` to `to`.\n *\n * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\n *\n * Requirements:\n *\n * - `from` cannot be the zero address.\n * - `to` cannot be the zero address.\n * - `tokenId` token must be owned by `from`.\n * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n *\n * Emits a {Transfer} event.\n */\n function transferFrom(\n address from,\n address to,\n uint256 tokenId\n ) external;\n\n /**\n * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n * The approval is cleared when the token is transferred.\n *\n * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\n *\n * Requirements:\n *\n * - The caller must own the token or be an approved operator.\n * - `tokenId` must exist.\n *\n * Emits an {Approval} event.\n */\n function approve(address to, uint256 tokenId) external;\n\n /**\n * @dev Returns the account approved for `tokenId` token.\n *\n * Requirements:\n *\n * - `tokenId` must exist.\n */\n function getApproved(uint256 tokenId) external view returns (address operator);\n\n /**\n * @dev Approve or remove `operator` as an operator for the caller.\n * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\n *\n * Requirements:\n *\n * - The `operator` cannot be the caller.\n *\n * Emits an {ApprovalForAll} event.\n */\n function setApprovalForAll(address operator, bool _approved) external;\n\n /**\n * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n *\n * See {setApprovalForAll}\n */\n function isApprovedForAll(address owner, address operator) external view returns (bool);\n\n /**\n * @dev Safely transfers `tokenId` token from `from` to `to`.\n *\n * Requirements:\n *\n * - `from` cannot be the zero address.\n * - `to` cannot be the zero address.\n * - `tokenId` token must exist and be owned by `from`.\n * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n *\n * Emits a {Transfer} event.\n */\n function safeTransferFrom(\n address from,\n address to,\n uint256 tokenId,\n bytes calldata data\n ) external;\n}\n" }, "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC721.sol\";\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ninterface IERC721Metadata is IERC721 {\n /**\n * @dev Returns the token collection name.\n */\n function name() external view returns (string memory);\n\n /**\n * @dev Returns the token collection symbol.\n */\n function symbol() external view returns (string memory);\n\n /**\n * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\n */\n function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n" }, "@openzeppelin/contracts/utils/introspection/IERC165.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165 {\n /**\n * @dev Returns true if this contract implements the interface defined by\n * `interfaceId`. See the corresponding\n * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n * to learn more about how these ids are created.\n *\n * This function call must use less than 30 000 gas.\n */\n function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n" }, "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ninterface IERC721Receiver {\n /**\n * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\n * by `operator` from `from`, this function is called.\n *\n * It must return its Solidity selector to confirm the token transfer.\n * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\n *\n * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.\n */\n function onERC721Received(\n address operator,\n address from,\n uint256 tokenId,\n bytes calldata data\n ) external returns (bytes4);\n}\n" }, "@openzeppelin/contracts/utils/Address.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)\n\npragma solidity ^0.8.1;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n /**\n * @dev Returns true if `account` is a contract.\n *\n * [IMPORTANT]\n * ====\n * It is unsafe to assume that an address for which this function returns\n * false is an externally-owned account (EOA) and not a contract.\n *\n * Among others, `isContract` will return false for the following\n * types of addresses:\n *\n * - an externally-owned account\n * - a contract in construction\n * - an address where a contract will be created\n * - an address where a contract lived, but was destroyed\n * ====\n *\n * [IMPORTANT]\n * ====\n * You shouldn't rely on `isContract` to protect against flash loan attacks!\n *\n * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets\n * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract\n * constructor.\n * ====\n */\n function isContract(address account) internal view returns (bool) {\n // This method relies on extcodesize/address.code.length, which returns 0\n // for contracts in construction, since the code is only stored at the end\n // of the constructor execution.\n\n return account.code.length > 0;\n }\n\n /**\n * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n * `recipient`, forwarding all available gas and reverting on errors.\n *\n * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n * of certain opcodes, possibly making contracts go over the 2300 gas limit\n * imposed by `transfer`, making them unable to receive funds via\n * `transfer`. {sendValue} removes this limitation.\n *\n * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n *\n * IMPORTANT: because control is transferred to `recipient`, care must be\n * taken to not create reentrancy vulnerabilities. Consider using\n * {ReentrancyGuard} or the\n * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n */\n function sendValue(address payable recipient, uint256 amount) internal {\n require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n (bool success, ) = recipient.call{value: amount}(\"\");\n require(success, \"Address: unable to send value, recipient may have reverted\");\n }\n\n /**\n * @dev Performs a Solidity function call using a low level `call`. A\n * plain `call` is an unsafe replacement for a function call: use this\n * function instead.\n *\n * If `target` reverts with a revert reason, it is bubbled up by this\n * function (like regular Solidity function calls).\n *\n * Returns the raw returned data. To convert to the expected return value,\n * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n *\n * Requirements:\n *\n * - `target` must be a contract.\n * - calling `target` with `data` must not revert.\n *\n * _Available since v3.1._\n */\n function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n return functionCall(target, data, \"Address: low-level call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n * `errorMessage` as a fallback revert reason when `target` reverts.\n *\n * _Available since v3.1._\n */\n function functionCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal returns (bytes memory) {\n return functionCallWithValue(target, data, 0, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but also transferring `value` wei to `target`.\n *\n * Requirements:\n *\n * - the calling contract must have an ETH balance of at least `value`.\n * - the called Solidity function must be `payable`.\n *\n * _Available since v3.1._\n */\n function functionCallWithValue(\n address target,\n bytes memory data,\n uint256 value\n ) internal returns (bytes memory) {\n return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n * with `errorMessage` as a fallback revert reason when `target` reverts.\n *\n * _Available since v3.1._\n */\n function functionCallWithValue(\n address target,\n bytes memory data,\n uint256 value,\n string memory errorMessage\n ) internal returns (bytes memory) {\n require(address(this).balance >= value, \"Address: insufficient balance for call\");\n require(isContract(target), \"Address: call to non-contract\");\n\n (bool success, bytes memory returndata) = target.call{value: value}(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but performing a static call.\n *\n * _Available since v3.3._\n */\n function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n return functionStaticCall(target, data, \"Address: low-level static call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n * but performing a static call.\n *\n * _Available since v3.3._\n */\n function functionStaticCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal view returns (bytes memory) {\n require(isContract(target), \"Address: static call to non-contract\");\n\n (bool success, bytes memory returndata) = target.staticcall(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but performing a delegate call.\n *\n * _Available since v3.4._\n */\n function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n * but performing a delegate call.\n *\n * _Available since v3.4._\n */\n function functionDelegateCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal returns (bytes memory) {\n require(isContract(target), \"Address: delegate call to non-contract\");\n\n (bool success, bytes memory returndata) = target.delegatecall(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the\n * revert reason using the provided one.\n *\n * _Available since v4.3._\n */\n function verifyCallResult(\n bool success,\n bytes memory returndata,\n string memory errorMessage\n ) internal pure returns (bytes memory) {\n if (success) {\n return returndata;\n } else {\n // Look for revert reason and bubble it up if present\n if (returndata.length > 0) {\n // The easiest way to bubble the revert reason is using memory via assembly\n\n assembly {\n let returndata_size := mload(returndata)\n revert(add(32, returndata), returndata_size)\n }\n } else {\n revert(errorMessage);\n }\n }\n }\n}\n" }, "@openzeppelin/contracts/utils/Context.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n function _msgSender() internal view virtual returns (address) {\n return msg.sender;\n }\n\n function _msgData() internal view virtual returns (bytes calldata) {\n return msg.data;\n }\n}\n" }, "@openzeppelin/contracts/utils/Strings.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev String operations.\n */\nlibrary Strings {\n bytes16 private constant _HEX_SYMBOLS = \"0123456789abcdef\";\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` decimal representation.\n */\n function toString(uint256 value) internal pure returns (string memory) {\n // Inspired by OraclizeAPI's implementation - MIT licence\n // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\n\n if (value == 0) {\n return \"0\";\n }\n uint256 temp = value;\n uint256 digits;\n while (temp != 0) {\n digits++;\n temp /= 10;\n }\n bytes memory buffer = new bytes(digits);\n while (value != 0) {\n digits -= 1;\n buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));\n value /= 10;\n }\n return string(buffer);\n }\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.\n */\n function toHexString(uint256 value) internal pure returns (string memory) {\n if (value == 0) {\n return \"0x00\";\n }\n uint256 temp = value;\n uint256 length = 0;\n while (temp != 0) {\n length++;\n temp >>= 8;\n }\n return toHexString(value, length);\n }\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.\n */\n function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {\n bytes memory buffer = new bytes(2 * length + 2);\n buffer[0] = \"0\";\n buffer[1] = \"x\";\n for (uint256 i = 2 * length + 1; i > 1; --i) {\n buffer[i] = _HEX_SYMBOLS[value & 0xf];\n value >>= 4;\n }\n require(value == 0, \"Strings: hex length insufficient\");\n return string(buffer);\n }\n}\n" }, "@openzeppelin/contracts/utils/introspection/ERC165.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC165.sol\";\n\n/**\n * @dev Implementation of the {IERC165} interface.\n *\n * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check\n * for the additional interface id that will be supported. For example:\n *\n * ```solidity\n * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);\n * }\n * ```\n *\n * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.\n */\nabstract contract ERC165 is IERC165 {\n /**\n * @dev See {IERC165-supportsInterface}.\n */\n function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n return interfaceId == type(IERC165).interfaceId;\n }\n}\n" }, "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC20.sol\";\nimport \"../../../utils/Address.sol\";\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n using Address for address;\n\n function safeTransfer(\n IERC20 token,\n address to,\n uint256 value\n ) internal {\n _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n }\n\n function safeTransferFrom(\n IERC20 token,\n address from,\n address to,\n uint256 value\n ) internal {\n _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n }\n\n /**\n * @dev Deprecated. This function has issues similar to the ones found in\n * {IERC20-approve}, and its usage is discouraged.\n *\n * Whenever possible, use {safeIncreaseAllowance} and\n * {safeDecreaseAllowance} instead.\n */\n function safeApprove(\n IERC20 token,\n address spender,\n uint256 value\n ) internal {\n // safeApprove should only be called when setting an initial allowance,\n // or when resetting it to zero. To increase and decrease it, use\n // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'\n require(\n (value == 0) || (token.allowance(address(this), spender) == 0),\n \"SafeERC20: approve from non-zero to non-zero allowance\"\n );\n _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n }\n\n function safeIncreaseAllowance(\n IERC20 token,\n address spender,\n uint256 value\n ) internal {\n uint256 newAllowance = token.allowance(address(this), spender) + value;\n _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n }\n\n function safeDecreaseAllowance(\n IERC20 token,\n address spender,\n uint256 value\n ) internal {\n unchecked {\n uint256 oldAllowance = token.allowance(address(this), spender);\n require(oldAllowance >= value, \"SafeERC20: decreased allowance below zero\");\n uint256 newAllowance = oldAllowance - value;\n _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n }\n }\n\n /**\n * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n * on the return value: the return value is optional (but if data is returned, it must not be false).\n * @param token The token targeted by the call.\n * @param data The call data (encoded using abi.encode or one of its variants).\n */\n function _callOptionalReturn(IERC20 token, bytes memory data) private {\n // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since\n // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n // the target address contains contract code and also asserts for success in the low-level call.\n\n bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n if (returndata.length > 0) {\n // Return data is optional\n require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n }\n }\n}\n" }, "@openzeppelin/contracts/token/ERC20/IERC20.sol": { "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n /**\n * @dev Returns the amount of tokens in existence.\n */\n function totalSupply() external view returns (uint256);\n\n /**\n * @dev Returns the amount of tokens owned by `account`.\n */\n function balanceOf(address account) external view returns (uint256);\n\n /**\n * @dev Moves `amount` tokens from the caller's account to `to`.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transfer(address to, uint256 amount) external returns (bool);\n\n /**\n * @dev Returns the remaining number of tokens that `spender` will be\n * allowed to spend on behalf of `owner` through {transferFrom}. This is\n * zero by default.\n *\n * This value changes when {approve} or {transferFrom} are called.\n */\n function allowance(address owner, address spender) external view returns (uint256);\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * IMPORTANT: Beware that changing an allowance with this method brings the risk\n * that someone may use both the old and the new allowance by unfortunate\n * transaction ordering. One possible solution to mitigate this race\n * condition is to first reduce the spender's allowance to 0 and set the\n * desired value afterwards:\n * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n *\n * Emits an {Approval} event.\n */\n function approve(address spender, uint256 amount) external returns (bool);\n\n /**\n * @dev Moves `amount` tokens from `from` to `to` using the\n * allowance mechanism. `amount` is then deducted from the caller's\n * allowance.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transferFrom(\n address from,\n address to,\n uint256 amount\n ) external returns (bool);\n\n /**\n * @dev Emitted when `value` tokens are moved from one account (`from`) to\n * another (`to`).\n *\n * Note that `value` may be zero.\n */\n event Transfer(address indexed from, address indexed to, uint256 value);\n\n /**\n * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n * a call to {approve}. `value` is the new allowance.\n */\n event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n" } }, "settings": { "optimizer": { "enabled": true, "runs": 200 }, "outputSelection": { "*": { "*": [ "evm.bytecode", "evm.deployedBytecode", "devdoc", "userdoc", "metadata", "abi" ] } }, "libraries": {} } }