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// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023. |
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// SPDX-License-Identifier: MIT
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pragma solidity ^0.8.4;
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import "./IERC721A.sol";
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/**
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* @dev Interface of ERC721 token receiver.
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*/
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interface ERC721A__IERC721Receiver {
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function onERC721Received(
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address operator,
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address from,
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uint256 tokenId,
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bytes calldata data
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) external returns (bytes4);
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}
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/**
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* @title ERC721A
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*
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* @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
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* Non-Fungible Token Standard, including the Metadata extension.
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* Optimized for lower gas during batch mints.
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*
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* Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
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* starting from `_startTokenId()`.
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*
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* Assumptions:
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*
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* - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
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* - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
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*/
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contract ERC721A is IERC721A {
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// Reference type for token approval.
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struct TokenApprovalRef {
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address value;
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}
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// =============================================================
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// CONSTANTS
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// =============================================================
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// Mask of an entry in packed address data.
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uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
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// The bit position of `numberMinted` in packed address data.
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uint256 private constant _BITPOS_NUMBER_MINTED = 64;
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// The bit position of `numberBurned` in packed address data.
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uint256 private constant _BITPOS_NUMBER_BURNED = 128;
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// The bit position of `aux` in packed address data.
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uint256 private constant _BITPOS_AUX = 192;
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// Mask of all 256 bits in packed address data except the 64 bits for `aux`.
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uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
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// The bit position of `startTimestamp` in packed ownership.
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uint256 private constant _BITPOS_START_TIMESTAMP = 160;
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// The bit mask of the `burned` bit in packed ownership.
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uint256 private constant _BITMASK_BURNED = 1 << 224;
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// The bit position of the `nextInitialized` bit in packed ownership.
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uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;
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// The bit mask of the `nextInitialized` bit in packed ownership.
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uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;
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// The bit position of `extraData` in packed ownership.
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uint256 private constant _BITPOS_EXTRA_DATA = 232;
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// Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
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uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
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// The mask of the lower 160 bits for addresses.
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uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;
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// The maximum `quantity` that can be minted with {_mintERC2309}.
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// This limit is to prevent overflows on the address data entries.
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// For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
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// is required to cause an overflow, which is unrealistic.
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uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
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// The `Transfer` event signature is given by:
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// `keccak256(bytes("Transfer(address,address,uint256)"))`.
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bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
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0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;
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// =============================================================
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// STORAGE
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// =============================================================
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// The next token ID to be minted.
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uint256 private _currentIndex;
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// The number of tokens burned.
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uint256 private _burnCounter;
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// Token name
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string private _name;
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// Token symbol
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string private _symbol;
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// Mapping from token ID to ownership details
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// An empty struct value does not necessarily mean the token is unowned.
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// See {_packedOwnershipOf} implementation for details.
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//
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// Bits Layout:
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// - [0..159] `addr`
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// - [160..223] `startTimestamp`
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// - [224] `burned`
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// - [225] `nextInitialized`
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// - [232..255] `extraData`
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mapping(uint256 => uint256) private _packedOwnerships;
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// Mapping owner address to address data.
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//
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// Bits Layout:
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// - [0..63] `balance`
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// - [64..127] `numberMinted`
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// - [128..191] `numberBurned`
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// - [192..255] `aux`
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mapping(address => uint256) private _packedAddressData;
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// Mapping from token ID to approved address.
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mapping(uint256 => TokenApprovalRef) private _tokenApprovals;
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// Mapping from owner to operator approvals
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mapping(address => mapping(address => bool)) private _operatorApprovals;
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// =============================================================
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// CONSTRUCTOR
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// =============================================================
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constructor(string memory name_, string memory symbol_) {
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_name = name_;
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_symbol = symbol_;
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_currentIndex = _startTokenId();
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}
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// =============================================================
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// TOKEN COUNTING OPERATIONS
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// =============================================================
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/**
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* @dev Returns the starting token ID.
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* To change the starting token ID, please override this function.
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*/
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function _startTokenId() internal view virtual returns (uint256) {
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return 1;
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}
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/**
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* @dev Returns the next token ID to be minted.
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*/
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function _nextTokenId() internal view virtual returns (uint256) {
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return _currentIndex;
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}
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/**
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* @dev Returns the total number of tokens in existence.
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* Burned tokens will reduce the count.
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* To get the total number of tokens minted, please see {_totalMinted}.
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*/
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function totalSupply() public view virtual override returns (uint256) {
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// Counter underflow is impossible as _burnCounter cannot be incremented
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// more than `_currentIndex - _startTokenId()` times.
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unchecked {
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return _currentIndex - _burnCounter - _startTokenId();
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}
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}
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/**
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* @dev Returns the total amount of tokens minted in the contract.
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*/
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function _totalMinted() internal view virtual returns (uint256) {
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// Counter underflow is impossible as `_currentIndex` does not decrement,
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// and it is initialized to `_startTokenId()`.
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unchecked {
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return _currentIndex - _startTokenId();
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}
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}
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/**
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* @dev Returns the total number of tokens burned.
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*/
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function _totalBurned() internal view virtual returns (uint256) {
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return _burnCounter;
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}
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// =============================================================
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// ADDRESS DATA OPERATIONS
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// =============================================================
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/**
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* @dev Returns the number of tokens in `owner`'s account.
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*/
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function balanceOf(address owner) public view virtual override returns (uint256) {
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if (owner == address(0)) revert BalanceQueryForZeroAddress();
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return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
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}
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/**
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* Returns the number of tokens minted by `owner`.
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*/
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function _numberMinted(address owner) internal view returns (uint256) {
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return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
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}
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/**
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* Returns the number of tokens burned by or on behalf of `owner`.
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*/
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function _numberBurned(address owner) internal view returns (uint256) {
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return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
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}
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/**
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* Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
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*/
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function _getAux(address owner) internal view returns (uint64) {
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return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
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}
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/**
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* Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
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* If there are multiple variables, please pack them into a uint64.
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*/
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function _setAux(address owner, uint64 aux) internal virtual {
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uint256 packed = _packedAddressData[owner];
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uint256 auxCasted;
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// Cast `aux` with assembly to avoid redundant masking.
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assembly {
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auxCasted := aux
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}
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packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
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_packedAddressData[owner] = packed;
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}
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// =============================================================
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// IERC165
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// =============================================================
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/**
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* @dev Returns true if this contract implements the interface defined by
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* `interfaceId`. See the corresponding
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* [EIP section](https://eips.ethereum.org/EIPS/eip-165
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* to learn more about how these ids are created.
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*
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* This function call must use less than 30000 gas.
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*/
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function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
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// The interface IDs are constants representing the first 4 bytes
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// of the XOR of all function selectors in the interface.
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// See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
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// (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
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return
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interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
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interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
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interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
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}
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// =============================================================
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// IERC721Metadata
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// =============================================================
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/**
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* @dev Returns the token collection name.
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*/
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function name() public view virtual override returns (string memory) {
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return _name;
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}
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/**
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* @dev Returns the token collection symbol.
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*/
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function symbol() public view virtual override returns (string memory) {
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return _symbol;
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}
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/**
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* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
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*/
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function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
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if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
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string memory baseURI = _baseURI();
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baseURI = string(abi.encodePacked(baseURI, _toString(tokenId)));
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return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, ".json")) : '';
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}
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/**
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* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
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* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
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* by default, it can be overridden in child contracts.
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*/
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function _baseURI() internal view virtual returns (string memory) {
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return '';
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}
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// =============================================================
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// OWNERSHIPS OPERATIONS
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// =============================================================
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/**
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* @dev Returns the owner of the `tokenId` token.
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*
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* Requirements:
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*
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* - `tokenId` must exist.
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*/
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function ownerOf(uint256 tokenId) public view virtual override returns (address) {
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return address(uint160(_packedOwnershipOf(tokenId)));
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}
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/**
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* @dev Gas spent here starts off proportional to the maximum mint batch size.
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* It gradually moves to O(1) as tokens get transferred around over time.
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*/
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function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
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return _unpackedOwnership(_packedOwnershipOf(tokenId));
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}
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/**
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* @dev Returns the unpacked `TokenOwnership` struct at `index`.
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*/
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function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
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return _unpackedOwnership(_packedOwnerships[index]);
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}
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/**
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* @dev Initializes the ownership slot minted at `index` for efficiency purposes.
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*/
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function _initializeOwnershipAt(uint256 index) internal virtual {
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if (_packedOwnerships[index] == 0) {
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_packedOwnerships[index] = _packedOwnershipOf(index);
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}
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}
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/**
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* Returns the packed ownership data of `tokenId`.
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*/
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function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
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uint256 curr = tokenId;
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unchecked {
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if (_startTokenId() <= curr)
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if (curr < _currentIndex) {
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uint256 packed = _packedOwnerships[curr];
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// If not burned.
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if (packed & _BITMASK_BURNED == 0) {
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// Invariant:
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// There will always be an initialized ownership slot
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// (i.e. `ownership.addr != address(0) && ownership.burned == false`)
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// before an unintialized ownership slot
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// (i.e. `ownership.addr == address(0) && ownership.burned == false`)
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// Hence, `curr` will not underflow.
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//
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// We can directly compare the packed value.
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// If the address is zero, packed will be zero.
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while (packed == 0) {
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packed = _packedOwnerships[--curr];
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}
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return packed;
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}
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}
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}
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revert OwnerQueryForNonexistentToken();
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}
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/**
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* @dev Returns the unpacked `TokenOwnership` struct from `packed`.
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*/
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function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
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ownership.addr = address(uint160(packed));
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ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
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ownership.burned = packed & _BITMASK_BURNED != 0;
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ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
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}
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/**
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* @dev Packs ownership data into a single uint256.
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*/
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function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
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assembly {
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// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
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owner := and(owner, _BITMASK_ADDRESS)
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// `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
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result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
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}
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}
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/**
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* @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
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*/
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function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
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// For branchless setting of the `nextInitialized` flag.
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assembly {
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// `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
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result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
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}
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}
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// =============================================================
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// APPROVAL OPERATIONS
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// =============================================================
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/**
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* @dev Gives permission to `to` to transfer `tokenId` token to another account.
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* The approval is cleared when the token is transferred.
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*
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* Only a single account can be approved at a time, so approving the
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* zero address clears previous approvals.
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*
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* Requirements:
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*
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* - The caller must own the token or be an approved operator.
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* - `tokenId` must exist.
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*
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* Emits an {Approval} event.
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*/
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function approve(address to, uint256 tokenId) public virtual override {
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address owner = ownerOf(tokenId);
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if (_msgSenderERC721A() != owner)
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if (!isApprovedForAll(owner, _msgSenderERC721A())) {
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revert ApprovalCallerNotOwnerNorApproved();
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}
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_tokenApprovals[tokenId].value = to;
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emit Approval(owner, to, tokenId);
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}
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/**
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* @dev Returns the account approved for `tokenId` token.
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*
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* Requirements:
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*
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* - `tokenId` must exist.
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*/
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function getApproved(uint256 tokenId) public view virtual override returns (address) {
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if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
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return _tokenApprovals[tokenId].value;
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}
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/**
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* @dev Approve or remove `operator` as an operator for the caller.
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* Operators can call {transferFrom} or {safeTransferFrom}
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* for any token owned by the caller.
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*
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* Requirements:
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*
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* - The `operator` cannot be the caller.
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*
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* Emits an {ApprovalForAll} event.
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*/
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function setApprovalForAll(address operator, bool approved) public virtual override {
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if (operator == _msgSenderERC721A()) revert ApproveToCaller();
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_operatorApprovals[_msgSenderERC721A()][operator] = approved;
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emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
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}
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/**
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* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
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*
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* See {setApprovalForAll}.
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*/
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function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
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return _operatorApprovals[owner][operator];
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}
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/**
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* @dev Returns whether `tokenId` exists.
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*
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* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
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*
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* Tokens start existing when they are minted. See {_mint}.
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*/
|
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function _exists(uint256 tokenId) internal view virtual returns (bool) {
|
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return
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_startTokenId() <= tokenId &&
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tokenId < _currentIndex && // If within bounds,
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_packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
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}
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/**
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* @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
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*/
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function _isSenderApprovedOrOwner(
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address approvedAddress,
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address owner,
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address msgSender
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) private pure returns (bool result) {
|
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assembly {
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// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
|
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owner := and(owner, _BITMASK_ADDRESS)
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// Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
|
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msgSender := and(msgSender, _BITMASK_ADDRESS)
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// `msgSender == owner || msgSender == approvedAddress`.
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result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
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}
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}
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|
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/**
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* @dev Returns the storage slot and value for the approved address of `tokenId`.
|
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*/
|
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function _getApprovedSlotAndAddress(uint256 tokenId)
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private
|
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view
|
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returns (uint256 approvedAddressSlot, address approvedAddress)
|
|
{
|
|
TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
|
|
// The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
|
|
assembly {
|
|
approvedAddressSlot := tokenApproval.slot
|
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approvedAddress := sload(approvedAddressSlot)
|
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}
|
|
}
|
|
|
|
// =============================================================
|
|
// TRANSFER OPERATIONS
|
|
// =============================================================
|
|
|
|
/**
|
|
* @dev Transfers `tokenId` from `from` to `to`.
|
|
*
|
|
* 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
|
|
) public virtual override {
|
|
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
|
|
|
|
if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();
|
|
|
|
(uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);
|
|
|
|
// The nested ifs save around 20+ gas over a compound boolean condition.
|
|
if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
|
|
if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
|
|
|
|
if (to == address(0)) revert TransferToZeroAddress();
|
|
|
|
_beforeTokenTransfers(from, to, tokenId, 1);
|
|
|
|
// Clear approvals from the previous owner.
|
|
assembly {
|
|
if approvedAddress {
|
|
// This is equivalent to `delete _tokenApprovals[tokenId]`.
|
|
sstore(approvedAddressSlot, 0)
|
|
}
|
|
}
|
|
|
|
// Underflow of the sender's balance is impossible because we check for
|
|
// ownership above and the recipient's balance can't realistically overflow.
|
|
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
|
|
unchecked {
|
|
// We can directly increment and decrement the balances.
|
|
--_packedAddressData[from]; // Updates: `balance -= 1`.
|
|
++_packedAddressData[to]; // Updates: `balance += 1`.
|
|
|
|
// Updates:
|
|
// - `address` to the next owner.
|
|
// - `startTimestamp` to the timestamp of transfering.
|
|
// - `burned` to `false`.
|
|
// - `nextInitialized` to `true`.
|
|
_packedOwnerships[tokenId] = _packOwnershipData(
|
|
to,
|
|
_BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
|
|
);
|
|
|
|
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
|
|
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
|
|
uint256 nextTokenId = tokenId + 1;
|
|
// If the next slot's address is zero and not burned (i.e. packed value is zero).
|
|
if (_packedOwnerships[nextTokenId] == 0) {
|
|
// If the next slot is within bounds.
|
|
if (nextTokenId != _currentIndex) {
|
|
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
|
|
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
emit Transfer(from, to, tokenId);
|
|
_afterTokenTransfers(from, to, tokenId, 1);
|
|
}
|
|
|
|
/**
|
|
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
|
|
*/
|
|
function safeTransferFrom(
|
|
address from,
|
|
address to,
|
|
uint256 tokenId
|
|
) public virtual override {
|
|
safeTransferFrom(from, to, tokenId, '');
|
|
}
|
|
|
|
/**
|
|
* @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 memory _data
|
|
) public virtual override {
|
|
transferFrom(from, to, tokenId);
|
|
if (to.code.length != 0)
|
|
if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
|
|
revert TransferToNonERC721ReceiverImplementer();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @dev Hook that is called before a set of serially-ordered token IDs
|
|
* are about to be transferred. This includes minting.
|
|
* And also called before burning one token.
|
|
*
|
|
* `startTokenId` - the first token ID to be transferred.
|
|
* `quantity` - the amount to be transferred.
|
|
*
|
|
* Calling conditions:
|
|
*
|
|
* - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
|
|
* transferred to `to`.
|
|
* - When `from` is zero, `tokenId` will be minted for `to`.
|
|
* - When `to` is zero, `tokenId` will be burned by `from`.
|
|
* - `from` and `to` are never both zero.
|
|
*/
|
|
function _beforeTokenTransfers(
|
|
address from,
|
|
address to,
|
|
uint256 startTokenId,
|
|
uint256 quantity
|
|
) internal virtual {}
|
|
|
|
/**
|
|
* @dev Hook that is called after a set of serially-ordered token IDs
|
|
* have been transferred. This includes minting.
|
|
* And also called after one token has been burned.
|
|
*
|
|
* `startTokenId` - the first token ID to be transferred.
|
|
* `quantity` - the amount to be transferred.
|
|
*
|
|
* Calling conditions:
|
|
*
|
|
* - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
|
|
* transferred to `to`.
|
|
* - When `from` is zero, `tokenId` has been minted for `to`.
|
|
* - When `to` is zero, `tokenId` has been burned by `from`.
|
|
* - `from` and `to` are never both zero.
|
|
*/
|
|
function _afterTokenTransfers(
|
|
address from,
|
|
address to,
|
|
uint256 startTokenId,
|
|
uint256 quantity
|
|
) internal virtual {}
|
|
|
|
/**
|
|
* @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
|
|
*
|
|
* `from` - Previous owner of the given token ID.
|
|
* `to` - Target address that will receive the token.
|
|
* `tokenId` - Token ID to be transferred.
|
|
* `_data` - Optional data to send along with the call.
|
|
*
|
|
* Returns whether the call correctly returned the expected magic value.
|
|
*/
|
|
function _checkContractOnERC721Received(
|
|
address from,
|
|
address to,
|
|
uint256 tokenId,
|
|
bytes memory _data
|
|
) private returns (bool) {
|
|
try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
|
|
bytes4 retval
|
|
) {
|
|
return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
|
|
} catch (bytes memory reason) {
|
|
if (reason.length == 0) {
|
|
revert TransferToNonERC721ReceiverImplementer();
|
|
} else {
|
|
assembly {
|
|
revert(add(32, reason), mload(reason))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// =============================================================
|
|
// MINT OPERATIONS
|
|
// =============================================================
|
|
|
|
/**
|
|
* @dev Mints `quantity` tokens and transfers them to `to`.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - `to` cannot be the zero address.
|
|
* - `quantity` must be greater than 0.
|
|
*
|
|
* Emits a {Transfer} event for each mint.
|
|
*/
|
|
function _mint(address to, uint256 quantity) internal virtual {
|
|
uint256 startTokenId = _currentIndex;
|
|
if (quantity == 0) revert MintZeroQuantity();
|
|
|
|
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
|
|
|
|
// Overflows are incredibly unrealistic.
|
|
// `balance` and `numberMinted` have a maximum limit of 2**64.
|
|
// `tokenId` has a maximum limit of 2**256.
|
|
unchecked {
|
|
// Updates:
|
|
// - `balance += quantity`.
|
|
// - `numberMinted += quantity`.
|
|
//
|
|
// We can directly add to the `balance` and `numberMinted`.
|
|
_packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
|
|
|
|
// Updates:
|
|
// - `address` to the owner.
|
|
// - `startTimestamp` to the timestamp of minting.
|
|
// - `burned` to `false`.
|
|
// - `nextInitialized` to `quantity == 1`.
|
|
_packedOwnerships[startTokenId] = _packOwnershipData(
|
|
to,
|
|
_nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
|
|
);
|
|
|
|
uint256 toMasked;
|
|
uint256 end = startTokenId + quantity;
|
|
|
|
// Use assembly to loop and emit the `Transfer` event for gas savings.
|
|
// The duplicated `log4` removes an extra check and reduces stack juggling.
|
|
// The assembly, together with the surrounding Solidity code, have been
|
|
// delicately arranged to nudge the compiler into producing optimized opcodes.
|
|
assembly {
|
|
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
|
|
toMasked := and(to, _BITMASK_ADDRESS)
|
|
// Emit the `Transfer` event.
|
|
log4(
|
|
0, // Start of data (0, since no data).
|
|
0, // End of data (0, since no data).
|
|
_TRANSFER_EVENT_SIGNATURE, // Signature.
|
|
0, // `address(0)`.
|
|
toMasked, // `to`.
|
|
startTokenId // `tokenId`.
|
|
)
|
|
|
|
for {
|
|
let tokenId := add(startTokenId, 1)
|
|
} iszero(eq(tokenId, end)) {
|
|
tokenId := add(tokenId, 1)
|
|
} {
|
|
// Emit the `Transfer` event. Similar to above.
|
|
log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
|
|
}
|
|
}
|
|
if (toMasked == 0) revert MintToZeroAddress();
|
|
|
|
_currentIndex = end;
|
|
}
|
|
_afterTokenTransfers(address(0), to, startTokenId, quantity);
|
|
}
|
|
|
|
/**
|
|
* @dev Mints `quantity` tokens and transfers them to `to`.
|
|
*
|
|
* This function is intended for efficient minting only during contract creation.
|
|
*
|
|
* It emits only one {ConsecutiveTransfer} as defined in
|
|
* [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
|
|
* instead of a sequence of {Transfer} event(s).
|
|
*
|
|
* Calling this function outside of contract creation WILL make your contract
|
|
* non-compliant with the ERC721 standard.
|
|
* For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
|
|
* {ConsecutiveTransfer} event is only permissible during contract creation.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - `to` cannot be the zero address.
|
|
* - `quantity` must be greater than 0.
|
|
*
|
|
* Emits a {ConsecutiveTransfer} event.
|
|
*/
|
|
function _mintERC2309(address to, uint256 quantity) internal virtual {
|
|
uint256 startTokenId = _currentIndex;
|
|
if (to == address(0)) revert MintToZeroAddress();
|
|
if (quantity == 0) revert MintZeroQuantity();
|
|
if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();
|
|
|
|
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
|
|
|
|
// Overflows are unrealistic due to the above check for `quantity` to be below the limit.
|
|
unchecked {
|
|
// Updates:
|
|
// - `balance += quantity`.
|
|
// - `numberMinted += quantity`.
|
|
//
|
|
// We can directly add to the `balance` and `numberMinted`.
|
|
_packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
|
|
|
|
// Updates:
|
|
// - `address` to the owner.
|
|
// - `startTimestamp` to the timestamp of minting.
|
|
// - `burned` to `false`.
|
|
// - `nextInitialized` to `quantity == 1`.
|
|
_packedOwnerships[startTokenId] = _packOwnershipData(
|
|
to,
|
|
_nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
|
|
);
|
|
|
|
emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);
|
|
|
|
_currentIndex = startTokenId + quantity;
|
|
}
|
|
_afterTokenTransfers(address(0), to, startTokenId, quantity);
|
|
}
|
|
|
|
/**
|
|
* @dev Safely mints `quantity` tokens and transfers them to `to`.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - If `to` refers to a smart contract, it must implement
|
|
* {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
|
|
* - `quantity` must be greater than 0.
|
|
*
|
|
* See {_mint}.
|
|
*
|
|
* Emits a {Transfer} event for each mint.
|
|
*/
|
|
function _safeMint(
|
|
address to,
|
|
uint256 quantity,
|
|
bytes memory _data
|
|
) internal virtual {
|
|
_mint(to, quantity);
|
|
|
|
unchecked {
|
|
if (to.code.length != 0) {
|
|
uint256 end = _currentIndex;
|
|
uint256 index = end - quantity;
|
|
do {
|
|
if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
|
|
revert TransferToNonERC721ReceiverImplementer();
|
|
}
|
|
} while (index < end);
|
|
// Reentrancy protection.
|
|
if (_currentIndex != end) revert();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @dev Equivalent to `_safeMint(to, quantity, '')`.
|
|
*/
|
|
function _safeMint(address to, uint256 quantity) internal virtual {
|
|
_safeMint(to, quantity, '');
|
|
}
|
|
|
|
// =============================================================
|
|
// BURN OPERATIONS
|
|
// =============================================================
|
|
|
|
/**
|
|
* @dev Equivalent to `_burn(tokenId, false)`.
|
|
*/
|
|
function _burn(uint256 tokenId) internal virtual {
|
|
_burn(tokenId, false);
|
|
}
|
|
|
|
/**
|
|
* @dev Destroys `tokenId`.
|
|
* The approval is cleared when the token is burned.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - `tokenId` must exist.
|
|
*
|
|
* Emits a {Transfer} event.
|
|
*/
|
|
function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
|
|
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
|
|
|
|
address from = address(uint160(prevOwnershipPacked));
|
|
|
|
(uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);
|
|
|
|
if (approvalCheck) {
|
|
// The nested ifs save around 20+ gas over a compound boolean condition.
|
|
if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
|
|
if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
|
|
}
|
|
|
|
_beforeTokenTransfers(from, address(0), tokenId, 1);
|
|
|
|
// Clear approvals from the previous owner.
|
|
assembly {
|
|
if approvedAddress {
|
|
// This is equivalent to `delete _tokenApprovals[tokenId]`.
|
|
sstore(approvedAddressSlot, 0)
|
|
}
|
|
}
|
|
|
|
// Underflow of the sender's balance is impossible because we check for
|
|
// ownership above and the recipient's balance can't realistically overflow.
|
|
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
|
|
unchecked {
|
|
// Updates:
|
|
// - `balance -= 1`.
|
|
// - `numberBurned += 1`.
|
|
//
|
|
// We can directly decrement the balance, and increment the number burned.
|
|
// This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
|
|
_packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;
|
|
|
|
// Updates:
|
|
// - `address` to the last owner.
|
|
// - `startTimestamp` to the timestamp of burning.
|
|
// - `burned` to `true`.
|
|
// - `nextInitialized` to `true`.
|
|
_packedOwnerships[tokenId] = _packOwnershipData(
|
|
from,
|
|
(_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
|
|
);
|
|
|
|
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
|
|
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
|
|
uint256 nextTokenId = tokenId + 1;
|
|
// If the next slot's address is zero and not burned (i.e. packed value is zero).
|
|
if (_packedOwnerships[nextTokenId] == 0) {
|
|
// If the next slot is within bounds.
|
|
if (nextTokenId != _currentIndex) {
|
|
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
|
|
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
emit Transfer(from, address(0), tokenId);
|
|
_afterTokenTransfers(from, address(0), tokenId, 1);
|
|
|
|
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
|
|
unchecked {
|
|
_burnCounter++;
|
|
}
|
|
}
|
|
|
|
// =============================================================
|
|
// EXTRA DATA OPERATIONS
|
|
// =============================================================
|
|
|
|
/**
|
|
* @dev Directly sets the extra data for the ownership data `index`.
|
|
*/
|
|
function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
|
|
uint256 packed = _packedOwnerships[index];
|
|
if (packed == 0) revert OwnershipNotInitializedForExtraData();
|
|
uint256 extraDataCasted;
|
|
// Cast `extraData` with assembly to avoid redundant masking.
|
|
assembly {
|
|
extraDataCasted := extraData
|
|
}
|
|
packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
|
|
_packedOwnerships[index] = packed;
|
|
}
|
|
|
|
/**
|
|
* @dev Called during each token transfer to set the 24bit `extraData` field.
|
|
* Intended to be overridden by the cosumer contract.
|
|
*
|
|
* `previousExtraData` - the value of `extraData` before transfer.
|
|
*
|
|
* Calling conditions:
|
|
*
|
|
* - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
|
|
* transferred to `to`.
|
|
* - When `from` is zero, `tokenId` will be minted for `to`.
|
|
* - When `to` is zero, `tokenId` will be burned by `from`.
|
|
* - `from` and `to` are never both zero.
|
|
*/
|
|
function _extraData(
|
|
address from,
|
|
address to,
|
|
uint24 previousExtraData
|
|
) internal view virtual returns (uint24) {}
|
|
|
|
/**
|
|
* @dev Returns the next extra data for the packed ownership data.
|
|
* The returned result is shifted into position.
|
|
*/
|
|
function _nextExtraData(
|
|
address from,
|
|
address to,
|
|
uint256 prevOwnershipPacked
|
|
) private view returns (uint256) {
|
|
uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
|
|
return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
|
|
}
|
|
|
|
// =============================================================
|
|
// OTHER OPERATIONS
|
|
// =============================================================
|
|
|
|
/**
|
|
* @dev Returns the message sender (defaults to `msg.sender`).
|
|
*
|
|
* If you are writing GSN compatible contracts, you need to override this function.
|
|
*/
|
|
function _msgSenderERC721A() internal view virtual returns (address) {
|
|
return msg.sender;
|
|
}
|
|
|
|
/**
|
|
* @dev Converts a uint256 to its ASCII string decimal representation.
|
|
*/
|
|
function _toString(uint256 value) internal pure virtual returns (string memory str) {
|
|
assembly {
|
|
// The maximum value of a uint256 contains 78 digits (1 byte per digit),
|
|
// but we allocate 0x80 bytes to keep the free memory pointer 32-byte word aligned.
|
|
// We will need 1 32-byte word to store the length,
|
|
// and 3 32-byte words to store a maximum of 78 digits. Total: 0x20 + 3 * 0x20 = 0x80.
|
|
str := add(mload(0x40), 0x80)
|
|
// Update the free memory pointer to allocate.
|
|
mstore(0x40, str)
|
|
|
|
// Cache the end of the memory to calculate the length later.
|
|
let end := str
|
|
|
|
// We write the string from rightmost digit to leftmost digit.
|
|
// The following is essentially a do-while loop that also handles the zero case.
|
|
// prettier-ignore
|
|
for { let temp := value } 1 {} {
|
|
str := sub(str, 1)
|
|
// Write the character to the pointer.
|
|
// The ASCII index of the '0' character is 48.
|
|
mstore8(str, add(48, mod(temp, 10)))
|
|
// Keep dividing `temp` until zero.
|
|
temp := div(temp, 10)
|
|
// prettier-ignore
|
|
if iszero(temp) { break }
|
|
}
|
|
|
|
let length := sub(end, str)
|
|
// Move the pointer 32 bytes leftwards to make room for the length.
|
|
str := sub(str, 0x20)
|
|
// Store the length.
|
|
mstore(str, length)
|
|
}
|
|
}
|
|
} |
