This is my contract code that implements ERC721A
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
import 'erc721a/contracts/ERC721A.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/utils/ReentrancyGuard.sol';
import '@openzeppelin/contracts/utils/Pausable.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/Address.sol';
contract Abba is ERC721A, Ownable, Pausable, ReentrancyGuard {
string private _baseTokenURI;
uint256 public mintPrice;
uint256 public immutable maxSupply;
uint256 public immutable maxBatchSizePerAddress;
uint256 public mintStart;
constructor(address initialOwner, uint256 collectionSize_, uint256 maxPerAddress_) ERC721A("Abba", "ABBA") Ownable(initialOwner) {
maxSupply = collectionSize_;
maxBatchSizePerAddress = maxPerAddress_;
}
//Mint function
function Mint(uint256 quantity) public payable whenNotPaused{
require(mintStart != 0 && block.timestamp >= mintStart, "Mint has not yet started!");
require(msg.value >= quantity * mintPrice, "Insufficient Funds");
require(_numberMinted(msg.sender) + quantity <= maxBatchSizePerAddress, "You can't mint more than this!");
require(_totalMinted() + quantity <= maxSupply, "All tokens sold out");
_mint(msg.sender, quantity);
}
//OwnerMint
function OwnerMint(uint256 quantity) public payable onlyOwner{
require(_totalMinted() + quantity <= maxSupply, "All tokens sold out");
_mint(msg.sender, quantity);
}
//Withdraw function
function WithdrawFunds() external onlyOwner nonReentrant{
uint256 balance = address(this).balance;
Address.sendValue(payable(msg.sender), balance);
}
//Metadata
function setBaseURI(string calldata baseURI) external onlyOwner{
_baseTokenURI = baseURI;
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseTokenURI;
}
function pause() external onlyOwner{
_pause();
}
function unpause() external onlyOwner{
_unpause();
}
//set mint date
function setMintDate(uint256 _mintDate) external onlyOwner{
mintStart = _mintDate;
}
//set price
function setMintPrice(uint64 _price) external onlyOwner{
mintPrice = _price;
}
}
Then this is the actual Chiru Labs ERC721A implementation
// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.3.0
// Creator: Chiru Labs
pragma solidity ^0.8.4;
import './IERC721A.sol';
/**
* @dev Interface of ERC721 token receiver.
*/
interface ERC721A__IERC721Receiver {
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
/**
* @title ERC721A
*
* @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
* Non-Fungible Token Standard, including the Metadata extension.
* Optimized for lower gas during batch mints.
*
* Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
* starting from `_startTokenId()`.
*
* The `_sequentialUpTo()` function can be overriden to enable spot mints
* (i.e. non-consecutive mints) for `tokenId`s greater than `_sequentialUpTo()`.
*
* Assumptions:
*
* - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
* - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
*/
contract ERC721A is IERC721A {
// Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
struct TokenApprovalRef {
address value;
}
// =============================================================
// CONSTANTS
// =============================================================
// Mask of an entry in packed address data.
uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
// The bit position of `numberMinted` in packed address data.
uint256 private constant _BITPOS_NUMBER_MINTED = 64;
// The bit position of `numberBurned` in packed address data.
uint256 private constant _BITPOS_NUMBER_BURNED = 128;
// The bit position of `aux` in packed address data.
uint256 private constant _BITPOS_AUX = 192;
// Mask of all 256 bits in packed address data except the 64 bits for `aux`.
uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
// The bit position of `startTimestamp` in packed ownership.
uint256 private constant _BITPOS_START_TIMESTAMP = 160;
// The bit mask of the `burned` bit in packed ownership.
uint256 private constant _BITMASK_BURNED = 1 << 224;
// The bit position of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;
// The bit mask of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;
// The bit position of `extraData` in packed ownership.
uint256 private constant _BITPOS_EXTRA_DATA = 232;
// Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
// The mask of the lower 160 bits for addresses.
uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;
// The maximum `quantity` that can be minted with {_mintERC2309}.
// This limit is to prevent overflows on the address data entries.
// For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
// is required to cause an overflow, which is unrealistic.
uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
// The `Transfer` event signature is given by:
// `keccak256(bytes("Transfer(address,address,uint256)"))`.
bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;
// =============================================================
// STORAGE
// =============================================================
// The next token ID to be minted.
uint256 private _currentIndex;
// The number of tokens burned.
uint256 private _burnCounter;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to ownership details
// An empty struct value does not necessarily mean the token is unowned.
// See {_packedOwnershipOf} implementation for details.
//
// Bits Layout:
// - [0..159] `addr`
// - [160..223] `startTimestamp`
// - [224] `burned`
// - [225] `nextInitialized`
// - [232..255] `extraData`
mapping(uint256 => uint256) private _packedOwnerships;
// Mapping owner address to address data.
//
// Bits Layout:
// - [0..63] `balance`
// - [64..127] `numberMinted`
// - [128..191] `numberBurned`
// - [192..255] `aux`
mapping(address => uint256) private _packedAddressData;
// Mapping from token ID to approved address.
mapping(uint256 => TokenApprovalRef) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
// The amount of tokens minted above `_sequentialUpTo()`.
// We call these spot mints (i.e. non-sequential mints).
uint256 private _spotMinted;
// =============================================================
// CONSTRUCTOR
// =============================================================
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_currentIndex = _startTokenId();
if (_sequentialUpTo() < _startTokenId()) _revert(SequentialUpToTooSmall.selector);
}
// =============================================================
// TOKEN COUNTING OPERATIONS
// =============================================================
/**
* @dev Returns the starting token ID for sequential mints.
*
* Override this function to change the starting token ID for sequential mints.
*
* Note: The value returned must never change after any tokens have been minted.
*/
function _startTokenId() internal view virtual returns (uint256) {
return 0;
}
/**
* @dev Returns the maximum token ID (inclusive) for sequential mints.
*
* Override this function to return a value less than 2**256 - 1,
* but greater than `_startTokenId()`, to enable spot (non-sequential) mints.
*
* Note: The value returned must never change after any tokens have been minted.
*/
function _sequentialUpTo() internal view virtual returns (uint256) {
return type(uint256).max;
}
/**
* @dev Returns the next token ID to be minted.
*/
function _nextTokenId() internal view virtual returns (uint256) {
return _currentIndex;
}
/**
* @dev Returns the total number of tokens in existence.
* Burned tokens will reduce the count.
* To get the total number of tokens minted, please see {_totalMinted}.
*/
function totalSupply() public view virtual override returns (uint256 result) {
// Counter underflow is impossible as `_burnCounter` cannot be incremented
// more than `_currentIndex + _spotMinted - _startTokenId()` times.
unchecked {
// With spot minting, the intermediate `result` can be temporarily negative,
// and the computation must be unchecked.
result = _currentIndex - _burnCounter - _startTokenId();
if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
}
}
/**
* @dev Returns the total amount of tokens minted in the contract.
*/
function _totalMinted() internal view virtual returns (uint256 result) {
// Counter underflow is impossible as `_currentIndex` does not decrement,
// and it is initialized to `_startTokenId()`.
unchecked {
result = _currentIndex - _startTokenId();
if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
}
}
/**
* @dev Returns the total number of tokens burned.
*/
function _totalBurned() internal view virtual returns (uint256) {
return _burnCounter;
}
/**
* @dev Returns the total number of tokens that are spot-minted.
*/
function _totalSpotMinted() internal view virtual returns (uint256) {
return _spotMinted;
}
// =============================================================
// ADDRESS DATA OPERATIONS
// =============================================================
/**
* @dev Returns the number of tokens in `owner`'s account.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
if (owner == address(0)) _revert(BalanceQueryForZeroAddress.selector);
return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens minted by `owner`.
*/
function _numberMinted(address owner) internal view returns (uint256) {
return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/
function _numberBurned(address owner) internal view returns (uint256) {
return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
*/
function _getAux(address owner) internal view returns (uint64) {
return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
}
/**
* Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
* If there are multiple variables, please pack them into a uint64.
*/
function _setAux(address owner, uint64 aux) internal virtual {
uint256 packed = _packedAddressData[owner];
uint256 auxCasted;
// Cast `aux` with assembly to avoid redundant masking.
assembly {
auxCasted := aux
}
packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
_packedAddressData[owner] = packed;
}
// =============================================================
// IERC165
// =============================================================
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
* to learn more about how these ids are created.
*
* This function call must use less than 30000 gas.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
// The interface IDs are constants representing the first 4 bytes
// of the XOR of all function selectors in the interface.
// See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
// (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
return
interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
}
// =============================================================
// IERC721Metadata
// =============================================================
/**
* @dev Returns the token collection name.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the token collection symbol.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
if (!_exists(tokenId)) _revert(URIQueryForNonexistentToken.selector);
string memory baseURI = _baseURI();
return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, it can be overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
// =============================================================
// OWNERSHIPS OPERATIONS
// =============================================================
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
return address(uint160(_packedOwnershipOf(tokenId)));
}
/**
* @dev Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around over time.
*/
function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
return _unpackedOwnership(_packedOwnershipOf(tokenId));
}
/**
* @dev Returns the unpacked `TokenOwnership` struct at `index`.
*/
function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
return _unpackedOwnership(_packedOwnerships[index]);
}
/**
* @dev Returns whether the ownership slot at `index` is initialized.
* An uninitialized slot does not necessarily mean that the slot has no owner.
*/
function _ownershipIsInitialized(uint256 index) internal view virtual returns (bool) {
return _packedOwnerships[index] != 0;
}
/**
* @dev Initializes the ownership slot minted at `index` for efficiency purposes.
*/
function _initializeOwnershipAt(uint256 index) internal virtual {
if (_packedOwnerships[index] == 0) {
_packedOwnerships[index] = _packedOwnershipOf(index);
}
}
/**
* @dev Returns the packed ownership data of `tokenId`.
*/
function _packedOwnershipOf(uint256 tokenId) private view returns (uint256 packed) {
if (_startTokenId() <= tokenId) {
packed = _packedOwnerships[tokenId];
if (tokenId > _sequentialUpTo()) {
if (_packedOwnershipExists(packed)) return packed;
_revert(OwnerQueryForNonexistentToken.selector);
}
// If the data at the starting slot does not exist, start the scan.
if (packed == 0) {
if (tokenId >= _currentIndex) _revert(OwnerQueryForNonexistentToken.selector);
// Invariant:
// There will always be an initialized ownership slot
// (i.e. `ownership.addr != address(0) && ownership.burned == false`)
// before an unintialized ownership slot
// (i.e. `ownership.addr == address(0) && ownership.burned == false`)
// Hence, `tokenId` will not underflow.
//
// We can directly compare the packed value.
// If the address is zero, packed will be zero.
for (;;) {
unchecked {
packed = _packedOwnerships[--tokenId];
}
if (packed == 0) continue;
if (packed & _BITMASK_BURNED == 0) return packed;
// Otherwise, the token is burned, and we must revert.
// This handles the case of batch burned tokens, where only the burned bit
// of the starting slot is set, and remaining slots are left uninitialized.
_revert(OwnerQueryForNonexistentToken.selector);
}
}
// Otherwise, the data exists and we can skip the scan.
// This is possible because we have already achieved the target condition.
// This saves 2143 gas on transfers of initialized tokens.
// If the token is not burned, return `packed`. Otherwise, revert.
if (packed & _BITMASK_BURNED == 0) return packed;
}
_revert(OwnerQueryForNonexistentToken.selector);
}
/**
* @dev Returns the unpacked `TokenOwnership` struct from `packed`.
*/
function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
ownership.addr = address(uint160(packed));
ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
ownership.burned = packed & _BITMASK_BURNED != 0;
ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
}
/**
* @dev Packs ownership data into a single uint256.
*/
function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
}
}
/**
* @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
*/
function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
// For branchless setting of the `nextInitialized` flag.
assembly {
// `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
}
}
// =============================================================
// APPROVAL OPERATIONS
// =============================================================
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account. See {ERC721A-_approve}.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
*/
function approve(address to, uint256 tokenId) public payable virtual override {
_approve(to, tokenId, true);
}
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
if (!_exists(tokenId)) _revert(ApprovalQueryForNonexistentToken.selector);
return _tokenApprovals[tokenId].value;
}
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom}
* for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
_operatorApprovals[_msgSenderERC721A()][operator] = approved;
emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
}
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted. See {_mint}.
*/
function _exists(uint256 tokenId) internal view virtual returns (bool result) {
if (_startTokenId() <= tokenId) {
if (tokenId > _sequentialUpTo()) return _packedOwnershipExists(_packedOwnerships[tokenId]);
if (tokenId < _currentIndex) {
uint256 packed;
while ((packed = _packedOwnerships[tokenId]) == 0) --tokenId;
result = packed & _BITMASK_BURNED == 0;
}
}
}
/**
* @dev Returns whether `packed` represents a token that exists.
*/
function _packedOwnershipExists(uint256 packed) private pure returns (bool result) {
assembly {
// The following is equivalent to `owner != address(0) && burned == false`.
// Symbolically tested.
result := gt(and(packed, _BITMASK_ADDRESS), and(packed, _BITMASK_BURNED))
}
}
/**
* @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
*/
function _isSenderApprovedOrOwner(
address approvedAddress,
address owner,
address msgSender
) private pure returns (bool result) {
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
msgSender := and(msgSender, _BITMASK_ADDRESS)
// `msgSender == owner || msgSender == approvedAddress`.
result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
}
}
/**
* @dev Returns the storage slot and value for the approved address of `tokenId`.
*/
function _getApprovedSlotAndAddress(uint256 tokenId)
private
view
returns (uint256 approvedAddressSlot, address approvedAddress)
{
TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
// The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
assembly {
approvedAddressSlot := tokenApproval.slot
approvedAddress := sload(approvedAddressSlot)
}
}
// =============================================================
// 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 payable virtual override {
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
// Mask `from` to the lower 160 bits, in case the upper bits somehow aren't clean.
from = address(uint160(uint256(uint160(from)) & _BITMASK_ADDRESS));
if (address(uint160(prevOwnershipPacked)) != from) _revert(TransferFromIncorrectOwner.selector);
(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.selector);
_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;
}
}
}
}
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;
assembly {
// 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.
from, // `from`.
toMasked, // `to`.
tokenId // `tokenId`.
)
}
if (toMasked == 0) _revert(TransferToZeroAddress.selector);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public payable 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 payable virtual override {
transferFrom(from, to, tokenId);
if (to.code.length != 0)
if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
_revert(TransferToNonERC721ReceiverImplementer.selector);
}
}
/**
* @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.selector);
}
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.selector);
_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:
// - `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)
);
// Updates:
// - `balance += quantity`.
// - `numberMinted += quantity`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;
if (toMasked == 0) _revert(MintToZeroAddress.selector);
uint256 end = startTokenId + quantity;
uint256 tokenId = startTokenId;
if (end - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);
do {
assembly {
// 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`.
tokenId // `tokenId`.
)
}
// The `!=` check ensures that large values of `quantity`
// that overflows uint256 will make the loop run out of gas.
} while (++tokenId != end);
_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.selector);
if (quantity == 0) _revert(MintZeroQuantity.selector);
if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) _revert(MintERC2309QuantityExceedsLimit.selector);
_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)
);
if (startTokenId + quantity - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);
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.selector);
}
} while (index < end);
// This prevents reentrancy to `_safeMint`.
// It does not prevent reentrancy to `_safeMintSpot`.
if (_currentIndex != end) revert();
}
}
}
/**
* @dev Equivalent to `_safeMint(to, quantity, '')`.
*/
function _safeMint(address to, uint256 quantity) internal virtual {
_safeMint(to, quantity, '');
}
/**
* @dev Mints a single token at `tokenId`.
*
* Note: A spot-minted `tokenId` that has been burned can be re-minted again.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` must be greater than `_sequentialUpTo()`.
* - `tokenId` must not exist.
*
* Emits a {Transfer} event for each mint.
*/
function _mintSpot(address to, uint256 tokenId) internal virtual {
if (tokenId <= _sequentialUpTo()) _revert(SpotMintTokenIdTooSmall.selector);
uint256 prevOwnershipPacked = _packedOwnerships[tokenId];
if (_packedOwnershipExists(prevOwnershipPacked)) _revert(TokenAlreadyExists.selector);
_beforeTokenTransfers(address(0), to, tokenId, 1);
// Overflows are incredibly unrealistic.
// The `numberMinted` for `to` is incremented by 1, and has a max limit of 2**64 - 1.
// `_spotMinted` is incremented by 1, and has a max limit of 2**256 - 1.
unchecked {
// Updates:
// - `address` to the owner.
// - `startTimestamp` to the timestamp of minting.
// - `burned` to `false`.
// - `nextInitialized` to `true` (as `quantity == 1`).
_packedOwnerships[tokenId] = _packOwnershipData(
to,
_nextInitializedFlag(1) | _nextExtraData(address(0), to, prevOwnershipPacked)
);
// Updates:
// - `balance += 1`.
// - `numberMinted += 1`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] += (1 << _BITPOS_NUMBER_MINTED) | 1;
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;
if (toMasked == 0) _revert(MintToZeroAddress.selector);
assembly {
// 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`.
tokenId // `tokenId`.
)
}
++_spotMinted;
}
_afterTokenTransfers(address(0), to, tokenId, 1);
}
/**
* @dev Safely mints a single token at `tokenId`.
*
* Note: A spot-minted `tokenId` that has been burned can be re-minted again.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}.
* - `tokenId` must be greater than `_sequentialUpTo()`.
* - `tokenId` must not exist.
*
* See {_mintSpot}.
*
* Emits a {Transfer} event.
*/
function _safeMintSpot(
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_mintSpot(to, tokenId);
unchecked {
if (to.code.length != 0) {
uint256 currentSpotMinted = _spotMinted;
if (!_checkContractOnERC721Received(address(0), to, tokenId, _data)) {
_revert(TransferToNonERC721ReceiverImplementer.selector);
}
// This prevents reentrancy to `_safeMintSpot`.
// It does not prevent reentrancy to `_safeMint`.
if (_spotMinted != currentSpotMinted) revert();
}
}
}
/**
* @dev Equivalent to `_safeMintSpot(to, tokenId, '')`.
*/
function _safeMintSpot(address to, uint256 tokenId) internal virtual {
_safeMintSpot(to, tokenId, '');
}
// =============================================================
// APPROVAL OPERATIONS
// =============================================================
/**
* @dev Equivalent to `_approve(to, tokenId, false)`.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_approve(to, tokenId, false);
}
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the
* zero address clears previous approvals.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function _approve(
address to,
uint256 tokenId,
bool approvalCheck
) internal virtual {
address owner = ownerOf(tokenId);
if (approvalCheck && _msgSenderERC721A() != owner)
if (!isApprovedForAll(owner, _msgSenderERC721A())) {
_revert(ApprovalCallerNotOwnerNorApproved.selector);
}
_tokenApprovals[tokenId].value = to;
emit Approval(owner, to, tokenId);
}
// =============================================================
// 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.selector);
}
_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 + _spotMinted` 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.selector);
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 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
// We will need 1 word for the trailing zeros padding, 1 word for the length,
// and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
let m := add(mload(0x40), 0xa0)
// Update the free memory pointer to allocate.
mstore(0x40, m)
// Assign the `str` to the end.
str := sub(m, 0x20)
// Zeroize the slot after the string.
mstore(str, 0)
// 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)
}
}
/**
* @dev For more efficient reverts.
*/
function _revert(bytes4 errorSelector) internal pure {
assembly {
mstore(0x00, errorSelector)
revert(0x00, 0x04)
}
}
}
To skip all that code, here's the actual withdraw function from my contract
//Withdraw function
function WithdrawFunds() external onlyOwner nonReentrant{
uint256 balance = address(this).balance;
Address.sendValue(payable(msg.sender), balance);
}
I'm sort of a beginner with Solidity and Javascript, so I don not know how to use evm_setNextBlockTimestamp
, using evm_increaseTime
was challenging enough. Do you mind explaining?