// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)pragmasolidity ^0.8.1;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0// for contracts in construction, since the code is only stored at the end// of the constructor execution.return account.code.length>0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value
) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytesmemory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytesmemory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytesmemory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
Contract Source Code
File 2 of 12: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragmasolidity ^0.8.0;/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 3 of 12: ERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)pragmasolidity ^0.8.0;import"./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 4 of 12: ERC721A.sol
// SPDX-License-Identifier: MIT// Creator: Chiru Labspragmasolidity ^0.8.4;import'@openzeppelin/contracts/token/ERC721/IERC721.sol';
import'@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import'@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
import'@openzeppelin/contracts/utils/Address.sol';
import'@openzeppelin/contracts/utils/Context.sol';
import'@openzeppelin/contracts/utils/Strings.sol';
import'@openzeppelin/contracts/utils/introspection/ERC165.sol';
errorApprovalCallerNotOwnerNorApproved();
errorApprovalQueryForNonexistentToken();
errorApproveToCaller();
errorApprovalToCurrentOwner();
errorBalanceQueryForZeroAddress();
errorMintToZeroAddress();
errorMintZeroQuantity();
errorOwnerQueryForNonexistentToken();
errorTransferCallerNotOwnerNorApproved();
errorTransferFromIncorrectOwner();
errorTransferToNonERC721ReceiverImplementer();
errorTransferToZeroAddress();
errorURIQueryForNonexistentToken();
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension. Built to optimize for lower gas during batch mints.
*
* Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
*
* Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
*
* Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
*/contractERC721AisContext, ERC165, IERC721, IERC721Metadata{
usingAddressforaddress;
usingStringsforuint256;
// Compiler will pack this into a single 256bit word.structTokenOwnership {
// The address of the owner.address addr;
// Keeps track of the start time of ownership with minimal overhead for tokenomics.uint64 startTimestamp;
// Whether the token has been burned.bool burned;
}
// Compiler will pack this into a single 256bit word.structAddressData {
// Realistically, 2**64-1 is more than enough.uint64 balance;
// Keeps track of mint count with minimal overhead for tokenomics.uint64 numberMinted;
// Keeps track of burn count with minimal overhead for tokenomics.uint64 numberBurned;
// For miscellaneous variable(s) pertaining to the address// (e.g. number of whitelist mint slots used).// If there are multiple variables, please pack them into a uint64.uint64 aux;
}
// The tokenId of the next token to be minted.uint256internal _currentIndex;
// The number of tokens burned.uint256internal _burnCounter;
// Token namestringprivate _name;
// Token symbolstringprivate _symbol;
// Mapping from token ID to ownership details// An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.mapping(uint256=> TokenOwnership) internal _ownerships;
// Mapping owner address to address datamapping(address=> AddressData) private _addressData;
// Mapping from token ID to approved addressmapping(uint256=>address) private _tokenApprovals;
// Mapping from owner to operator approvalsmapping(address=>mapping(address=>bool)) private _operatorApprovals;
constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
_currentIndex = _startTokenId();
}
/**
* To change the starting tokenId, please override this function.
*/function_startTokenId() internalviewvirtualreturns (uint256) {
return0;
}
/**
* @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
*/functiontotalSupply() publicviewreturns (uint256) {
// Counter underflow is impossible as _burnCounter cannot be incremented// more than _currentIndex - _startTokenId() timesunchecked {
return _currentIndex - _burnCounter - _startTokenId();
}
}
/**
* Returns the total amount of tokens minted in the contract.
*/function_totalMinted() internalviewreturns (uint256) {
// Counter underflow is impossible as _currentIndex does not decrement,// and it is initialized to _startTokenId()unchecked {
return _currentIndex - _startTokenId();
}
}
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverride(ERC165, IERC165) returns (bool) {
return
interfaceId ==type(IERC721).interfaceId||
interfaceId ==type(IERC721Metadata).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/functionbalanceOf(address owner) publicviewoverridereturns (uint256) {
if (owner ==address(0)) revert BalanceQueryForZeroAddress();
returnuint256(_addressData[owner].balance);
}
/**
* Returns the number of tokens minted by `owner`.
*/function_numberMinted(address owner) internalviewreturns (uint256) {
returnuint256(_addressData[owner].numberMinted);
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/function_numberBurned(address owner) internalviewreturns (uint256) {
returnuint256(_addressData[owner].numberBurned);
}
/**
* Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
*/function_getAux(address owner) internalviewreturns (uint64) {
return _addressData[owner].aux;
}
/**
* Sets the auxillary 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{
_addressData[owner].aux = aux;
}
/**
* Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around in the collection over time.
*/function_ownershipOf(uint256 tokenId) internalviewreturns (TokenOwnership memory) {
uint256 curr = tokenId;
unchecked {
if (_startTokenId() <= curr && curr < _currentIndex) {
TokenOwnership memory ownership = _ownerships[curr];
if (!ownership.burned) {
if (ownership.addr !=address(0)) {
return ownership;
}
// Invariant:// There will always be an ownership that has an address and is not burned// before an ownership that does not have an address and is not burned.// Hence, curr will not underflow.while (true) {
curr--;
ownership = _ownerships[curr];
if (ownership.addr !=address(0)) {
return ownership;
}
}
}
}
}
revert OwnerQueryForNonexistentToken();
}
/**
* @dev See {IERC721-ownerOf}.
*/functionownerOf(uint256 tokenId) publicviewoverridereturns (address) {
return _ownershipOf(tokenId).addr;
}
/**
* @dev See {IERC721Metadata-name}.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/functiontokenURI(uint256 tokenId) publicviewvirtualoverridereturns (stringmemory) {
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
stringmemory baseURI = _baseURI();
returnbytes(baseURI).length!=0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
}
/**
* @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, can be overriden in child contracts.
*/function_baseURI() internalviewvirtualreturns (stringmemory) {
return'';
}
/**
* @dev See {IERC721-approve}.
*/functionapprove(address to, uint256 tokenId) publicoverride{
address owner = ERC721A.ownerOf(tokenId);
if (to == owner) revert ApprovalToCurrentOwner();
if (_msgSender() != owner &&!isApprovedForAll(owner, _msgSender())) {
revert ApprovalCallerNotOwnerNorApproved();
}
_approve(to, tokenId, owner);
}
/**
* @dev See {IERC721-getApproved}.
*/functiongetApproved(uint256 tokenId) publicviewoverridereturns (address) {
if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/functionsetApprovalForAll(address operator, bool approved) publicvirtualoverride{
if (operator == _msgSender()) revert ApproveToCaller();
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/functionisApprovedForAll(address owner, address operator) publicviewvirtualoverridereturns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/functiontransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
safeTransferFrom(from, to, tokenId, '');
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) publicvirtualoverride{
_transfer(from, to, tokenId);
if (to.isContract() &&!_checkContractOnERC721Received(from, to, tokenId, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
}
/**
* @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 (`_mint`),
*/function_exists(uint256 tokenId) internalviewreturns (bool) {
return _startTokenId() <= tokenId && tokenId < _currentIndex &&!_ownerships[tokenId].burned;
}
function_safeMint(address to, uint256 quantity) internal{
_safeMint(to, 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.
*
* Emits a {Transfer} event.
*/function_safeMint(address to,
uint256 quantity,
bytesmemory _data
) internal{
_mint(to, quantity, _data, true);
}
/**
* @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.
*/function_mint(address to,
uint256 quantity,
bytesmemory _data,
bool safe
) internal{
uint256 startTokenId = _currentIndex;
if (to ==address(0)) revert MintToZeroAddress();
if (quantity ==0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.// balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1// updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1unchecked {
_addressData[to].balance+=uint64(quantity);
_addressData[to].numberMinted +=uint64(quantity);
_ownerships[startTokenId].addr = to;
_ownerships[startTokenId].startTimestamp =uint64(block.timestamp);
uint256 updatedIndex = startTokenId;
uint256 end = updatedIndex + quantity;
if (safe && to.isContract()) {
do {
emit Transfer(address(0), to, updatedIndex);
if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
} while (updatedIndex != end);
// Reentrancy protectionif (_currentIndex != startTokenId) revert();
} else {
do {
emit Transfer(address(0), to, updatedIndex++);
} while (updatedIndex != end);
}
_currentIndex = updatedIndex;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/function_transfer(addressfrom,
address to,
uint256 tokenId
) private{
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
if (prevOwnership.addr !=from) revert TransferFromIncorrectOwner();
bool isApprovedOrOwner = (_msgSender() ==from||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
if (to ==address(0)) revert TransferToZeroAddress();
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// 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 {
_addressData[from].balance-=1;
_addressData[to].balance+=1;
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = to;
currSlot.startTimestamp =uint64(block.timestamp);
// If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr ==address(0)) {
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId != _currentIndex) {
nextSlot.addr =from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev This is equivalent to _burn(tokenId, false)
*/function_burn(uint256 tokenId) internalvirtual{
_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) internalvirtual{
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
addressfrom= prevOwnership.addr;
if (approvalCheck) {
bool isApprovedOrOwner = (_msgSender() ==from||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
}
_beforeTokenTransfers(from, address(0), tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// 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 {
AddressData storage addressData = _addressData[from];
addressData.balance-=1;
addressData.numberBurned +=1;
// Keep track of who burned the token, and the timestamp of burning.
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr =from;
currSlot.startTimestamp =uint64(block.timestamp);
currSlot.burned =true;
// If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr ==address(0)) {
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId != _currentIndex) {
nextSlot.addr =from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, address(0), tokenId);
_afterTokenTransfers(from, address(0), tokenId, 1);
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.unchecked {
_burnCounter++;
}
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/function_approve(address to,
uint256 tokenId,
address owner
) private{
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/function_checkContractOnERC721Received(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) privatereturns (bool) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytesmemory reason) {
if (reason.length==0) {
revert TransferToNonERC721ReceiverImplementer();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
/**
* @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(addressfrom,
address to,
uint256 startTokenId,
uint256 quantity
) internalvirtual{}
/**
* @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(addressfrom,
address to,
uint256 startTokenId,
uint256 quantity
) internalvirtual{}
}
Contract Source Code
File 5 of 12: IERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/interfaceIERC165{
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/functionsupportsInterface(bytes4 interfaceId) externalviewreturns (bool);
}
Contract Source Code
File 6 of 12: IERC721.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)pragmasolidity ^0.8.0;import"../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/interfaceIERC721isIERC165{
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/eventApproval(addressindexed owner, addressindexed approved, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/functionbalanceOf(address owner) externalviewreturns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functionownerOf(uint256 tokenId) externalviewreturns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/functiontransferFrom(addressfrom,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/functionapprove(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/functionsetApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytescalldata data
) external;
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)pragmasolidity ^0.8.0;/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/interfaceIERC721Receiver{
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/functiononERC721Received(address operator,
addressfrom,
uint256 tokenId,
bytescalldata data
) externalreturns (bytes4);
}
Contract Source Code
File 9 of 12: MerkleProof.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol)pragmasolidity ^0.8.0;/**
* @dev These functions deal with verification of Merkle Trees proofs.
*
* The proofs can be generated using the JavaScript library
* https://github.com/miguelmota/merkletreejs[merkletreejs].
* Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
*
* See `test/utils/cryptography/MerkleProof.test.js` for some examples.
*/libraryMerkleProof{
/**
* @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
* defined by `root`. For this, a `proof` must be provided, containing
* sibling hashes on the branch from the leaf to the root of the tree. Each
* pair of leaves and each pair of pre-images are assumed to be sorted.
*/functionverify(bytes32[] memory proof,
bytes32 root,
bytes32 leaf
) internalpurereturns (bool) {
return processProof(proof, leaf) == root;
}
/**
* @dev Returns the rebuilt hash obtained by traversing a Merklee tree up
* from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
* hash matches the root of the tree. When processing the proof, the pairs
* of leafs & pre-images are assumed to be sorted.
*
* _Available since v4.4._
*/functionprocessProof(bytes32[] memory proof, bytes32 leaf) internalpurereturns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i =0; i < proof.length; i++) {
bytes32 proofElement = proof[i];
if (computedHash <= proofElement) {
// Hash(current computed hash + current element of the proof)
computedHash = _efficientHash(computedHash, proofElement);
} else {
// Hash(current element of the proof + current computed hash)
computedHash = _efficientHash(proofElement, computedHash);
}
}
return computedHash;
}
function_efficientHash(bytes32 a, bytes32 b) privatepurereturns (bytes32 value) {
assembly {
mstore(0x00, a)
mstore(0x20, b)
value :=keccak256(0x00, 0x40)
}
}
}
Contract Source Code
File 10 of 12: MutantShibaClub.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.9;/*
MM
MMMM
MMMMM
MMMMMM MM
MMM MMM
MMMMM
M MMMMMMMMMM MMMMMM
MMMM MMMMMMMMMMMMM MMMM
MMMMMM MMMMMMMMMMMMMM MM
MMMMMM MMMMMMMMMMMMMMM MMMMMMMMMM
MMMM MMMMMMMMMMMMMMM MMMMMMMMMMMM
MMMM MMMMMMMMMMMMMMM MMMMMMMMMMMMM
MMMMMMMMMMM MMMMMMMMMMMMMM MMMMMMMMMMMMMM
MMMMMMMMMMMMMM MMMMMMMMMMMM MMMMMMMMMMMMMMM
MMMMMMMMMMMMMMM MMMMMMMMMM MMMMMMMMMMMMMM
MMMMMMMMMMMMMMMM MMMMMMMMM MMMMMMMMMMMMMM
MMMMMMMMMMMMMMMM MMM MMM MMMMMMMMMMMMMM
MMMMMMMMMMMMMMMM MMMM MMMMMMM
MM MMMMMMMMMMMMMMMM
MMMM MMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMM MMM MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMM MM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMM
MMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMM
MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMM
MMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMM
M MMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
M MM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMM
MMMMMMMM MMM
MMMMMM M
MMMMMM
MMMMM
MMMMM
MMMMM
MMMM
MM
*/import"./ERC721A.sol";
import"@openzeppelin/contracts/access/Ownable.sol";
import"@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
contractMutantShibaClubisERC721A, Ownable{
usingStringsforuint256;
// ======== SUPPLY ========uint256publicconstant MAX_SUPPLY =10000;
// ======== MAX MINTS ========uint256public maxCommunityMint =1;
uint256public maxPublicSaleMint =1;
// ======== PRICE ========uint256public publicSalePrice;
uint256public communitySalePrice;
uint256public preSalePrice =0.16ether;
uint256public teamMintPrice =0.1ether;
// ======== SALE STATUS ========boolpublic isPreSaleActive;
boolpublic isCommunitySaleActive;
boolpublic isPublicSaleActive;
// ======== METADATA ========boolpublic isRevealed;
stringprivate _baseTokenURI;
// ======== MERKLE ROOT ========bytes32public preSaleMerkleRoot;
bytes32public communitySaleMerkleRoot;
// ======== MINTED ========mapping(address=>uint256) public preSaleMinted;
mapping(address=>bool) public communitySaleMinted;
mapping(address=>uint256) public publicSaleMinted;
// ======== GNOSIS ========addresspublicconstant GNOSIS_SAFE =0xe16B650921475afA532f7C08A8eA1C2fCDa8ab93;
// ======== FOUNDERS & TEAM ======== addresspublicconstant TEAM =0xcdBB9a281f1086aEcB6c4d5ac290130c1A8778De;
addresspublicconstant FOUNDER_BERRY =0x28C1dEd0D767fDC39530f676362175afe35E96B4;
addresspublicconstant FOUNDER_GABA =0xbe14e8d7a3417046627f305C918eC435C3c23fbC;
addresspublicconstant FOUNDER_LORDSLABS =0xbb59f8ce665d238A9e8D942172D283ba87061F6F;
addresspublicconstant FOUNDER_CRAZYJUMP =0xE386aE197A42e49C727BF15070FE71C68F18ad45;
// ======== CONSTRUCTOR ======== constructor() ERC721A("Mutant Shiba Club", "MSC") {}
/**
* @notice must be an EOA
*/modifiercallerIsUser() {
require(tx.origin==msg.sender, "The caller is another contract");
_;
}
// ======== MINTING ========/**
* @notice presale mint
*/functionpreSaleMint(uint256 _quantity, uint256 _maxAmount, bytes32[] calldata _proof) externalpayablecallerIsUser{
require(isPreSaleActive, "PRESALE NOT ACTIVE");
require(msg.value== preSalePrice * _quantity, "NEED TO SEND CORRECT ETH AMOUNT");
require(totalSupply() + _quantity <= MAX_SUPPLY, "MAX SUPPLY REACHED" );
require(preSaleMinted[msg.sender] + _quantity <= _maxAmount, "EXCEEDS MAX CLAIM");
bytes32 sender =keccak256(abi.encodePacked(msg.sender, _maxAmount));
bool isValidProof = MerkleProof.verify(_proof, preSaleMerkleRoot, sender);
require(isValidProof, "INVALID PROOF");
preSaleMinted[msg.sender] += _quantity;
_safeMint(msg.sender, _quantity);
}
/**
* @notice community sale mint
*/functioncommunitySaleMint(bytes32[] calldata _proof) externalpayablecallerIsUser{
require(isCommunitySaleActive, "COMMUNITY SALE NOT ACTIVE");
require(msg.value== communitySalePrice, "NEED TO SEND CORRECT ETH AMOUNT");
require(totalSupply() + maxCommunityMint <= MAX_SUPPLY, "MAX SUPPLY REACHED" );
require(!communitySaleMinted[msg.sender], "EXCEEDS MAX CLAIM");
bytes32 sender =keccak256(abi.encodePacked(msg.sender));
bool isValidProof = MerkleProof.verify(_proof, communitySaleMerkleRoot, sender);
require(isValidProof, "INVALID PROOF");
communitySaleMinted[msg.sender] =true;
_safeMint(msg.sender, maxCommunityMint);
}
/**
* @notice public sale mint
*/functionpublicSaleMint(uint256 _quantity) externalpayablecallerIsUser{
require(isPublicSaleActive, "PUBLIC SALE IS NOT ACTIVE");
require(totalSupply() + _quantity <= MAX_SUPPLY, "MAX SUPPLY REACHED" );
require(publicSaleMinted[msg.sender] + _quantity <= maxPublicSaleMint, "EXCEEDS MAX MINTS PER ADDRESS");
require(msg.value== publicSalePrice * _quantity, "NEED TO SEND CORRECT ETH AMOUNT");
publicSaleMinted[msg.sender] += _quantity;
_safeMint(msg.sender, _quantity);
}
functionteamMint(uint256 _quantity, bool _founders) externalpayableonlyOwner{
require(totalSupply() + _quantity <= MAX_SUPPLY, "MAX SUPPLY REACHED" );
require(msg.value== teamMintPrice, "NEED TO SEND CORRECT ETH AMOUNT");
if (_founders) {
// ======== FOUNDER MINT ========
_safeMint(FOUNDER_BERRY, 15);
_safeMint(FOUNDER_GABA, 15);
_safeMint(FOUNDER_LORDSLABS, 15);
_safeMint(FOUNDER_CRAZYJUMP, 15);
// ======== TEAM MINT ========
_safeMint(TEAM, 40);
_safeMint(TEAM, 43);
_safeMint(TEAM, 57);
} else {
// ======== TEAM MINT ========
_safeMint(TEAM, _quantity);
}
}
// ======== SALE STATUS SETTERS ========/**
* @notice activating or deactivating presale status
*/functionsetPreSaleStatus(bool _status) externalonlyOwner{
isPreSaleActive = _status;
}
/**
* @notice activating or deactivating community sale status
*/functionsetCommunitySaleStatus(bool _status) externalonlyOwner{
isCommunitySaleActive = _status;
}
/**
* @notice activating or deactivating public sale
*/functionsetPublicSaleStatus(bool _status) externalonlyOwner{
isPublicSaleActive = _status;
}
// ======== PRICE SETTERS ========/**
* @notice set presale price
*/functionsetPreSalePrice(uint256 _price) externalonlyOwner{
preSalePrice = _price;
}
/**
* @notice set whitelist price
*/functionsetCommunitySalePrice(uint256 _price) externalonlyOwner{
communitySalePrice = _price;
}
/**
* @notice set public sale price
*/functionsetPublicSalePrice(uint256 _price) externalonlyOwner{
publicSalePrice = _price;
}
// ======== MERKLE ROOT SETTERS ========/**
* @notice set presale merkleroot
*/functionsetPresaleMerkleRoot(bytes32 _merkleRoot) externalonlyOwner{
preSaleMerkleRoot = _merkleRoot;
}
/**
* @notice set community sale merkleroot
*/functionsetCommunitySaleMerkleRoot(bytes32 _merkleRoot) externalonlyOwner{
communitySaleMerkleRoot = _merkleRoot;
}
// ======== METADATA URI ========/**
* @notice tokenURI
*/functiontokenURI(uint256 _tokenId) publicviewvirtualoverridereturns (stringmemory) {
require(_exists(_tokenId), "URI query for non-existent token");
if (!isRevealed) {
return _baseTokenURI;
} else{
returnstring(abi.encodePacked(_baseTokenURI, _tokenId.toString()));
}
}
/**
* @notice set base URI
*/functionsetBaseURI(stringcalldata baseURI) externalonlyOwner{
_baseTokenURI = baseURI;
}
/**
* @notice set IsRevealed to true or false
*/functionsetIsRevealed(bool _reveal) externalonlyOwner{
isRevealed = _reveal;
}
/**
* @notice set startTokenId to 1
*/function_startTokenId() internalviewvirtualoverride(ERC721A) returns (uint256) {
return1;
}
// ======== WITHDRAW GNOSIS ========/**
* @notice withdraw funds to gnosis safe
*/functionwithdraw() externalonlyOwner{
(bool success, ) = GNOSIS_SAFE.call{value: address(this).balance}("");
require(success, "Transfer failed.");
}
}
Contract Source Code
File 11 of 12: Ownable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)pragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
require(newOwner !=address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/function_transferOwnership(address newOwner) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
Contract Source Code
File 12 of 12: Strings.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)pragmasolidity ^0.8.0;/**
* @dev String operations.
*/libraryStrings{
bytes16privateconstant _HEX_SYMBOLS ="0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/functiontoString(uint256 value) internalpurereturns (stringmemory) {
// Inspired by OraclizeAPI's implementation - MIT licence// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.solif (value ==0) {
return"0";
}
uint256 temp = value;
uint256 digits;
while (temp !=0) {
digits++;
temp /=10;
}
bytesmemory buffer =newbytes(digits);
while (value !=0) {
digits -=1;
buffer[digits] =bytes1(uint8(48+uint256(value %10)));
value /=10;
}
returnstring(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/functiontoHexString(uint256 value) internalpurereturns (stringmemory) {
if (value ==0) {
return"0x00";
}
uint256 temp = value;
uint256 length =0;
while (temp !=0) {
length++;
temp >>=8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/functiontoHexString(uint256 value, uint256 length) internalpurereturns (stringmemory) {
bytesmemory buffer =newbytes(2* length +2);
buffer[0] ="0";
buffer[1] ="x";
for (uint256 i =2* length +1; i >1; --i) {
buffer[i] = _HEX_SYMBOLS[value &0xf];
value >>=4;
}
require(value ==0, "Strings: hex length insufficient");
returnstring(buffer);
}
}