// SPDX-License-Identifier: AGPL-3.0-onlypragmasolidity >=0.8.0;/// @notice Modern, minimalist, and gas efficient ERC-721 implementation./// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC721.sol)abstractcontractERC721{
/*//////////////////////////////////////////////////////////////
EVENTS
//////////////////////////////////////////////////////////////*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed id);
eventApproval(addressindexed owner, addressindexed spender, uint256indexed id);
eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/*//////////////////////////////////////////////////////////////
METADATA STORAGE/LOGIC
//////////////////////////////////////////////////////////////*/stringpublic name;
stringpublic symbol;
functiontokenURI(uint256 id) publicviewvirtualreturns (stringmemory);
/*//////////////////////////////////////////////////////////////
ERC721 BALANCE/OWNER STORAGE
//////////////////////////////////////////////////////////////*/mapping(uint256=>address) internal _ownerOf;
mapping(address=>uint256) internal _balanceOf;
functionownerOf(uint256 id) publicviewvirtualreturns (address owner) {
require((owner = _ownerOf[id]) !=address(0), "NOT_MINTED");
}
functionbalanceOf(address owner) publicviewvirtualreturns (uint256) {
require(owner !=address(0), "ZERO_ADDRESS");
return _balanceOf[owner];
}
/*//////////////////////////////////////////////////////////////
ERC721 APPROVAL STORAGE
//////////////////////////////////////////////////////////////*/mapping(uint256=>address) public getApproved;
mapping(address=>mapping(address=>bool)) public isApprovedForAll;
/*//////////////////////////////////////////////////////////////
CONSTRUCTOR
//////////////////////////////////////////////////////////////*/constructor(stringmemory _name, stringmemory _symbol) {
name = _name;
symbol = _symbol;
}
/*//////////////////////////////////////////////////////////////
ERC721 LOGIC
//////////////////////////////////////////////////////////////*/functionapprove(address spender, uint256 id) publicvirtual{
address owner = _ownerOf[id];
require(msg.sender== owner || isApprovedForAll[owner][msg.sender], "NOT_AUTHORIZED");
getApproved[id] = spender;
emit Approval(owner, spender, id);
}
functionsetApprovalForAll(address operator, bool approved) publicvirtual{
isApprovedForAll[msg.sender][operator] = approved;
emit ApprovalForAll(msg.sender, operator, approved);
}
functiontransferFrom(addressfrom,
address to,
uint256 id
) publicvirtual{
require(from== _ownerOf[id], "WRONG_FROM");
require(to !=address(0), "INVALID_RECIPIENT");
require(
msg.sender==from|| isApprovedForAll[from][msg.sender] ||msg.sender== getApproved[id],
"NOT_AUTHORIZED"
);
// Underflow of the sender's balance is impossible because we check for// ownership above and the recipient's balance can't realistically overflow.unchecked {
_balanceOf[from]--;
_balanceOf[to]++;
}
_ownerOf[id] = to;
delete getApproved[id];
emit Transfer(from, to, id);
}
functionsafeTransferFrom(addressfrom,
address to,
uint256 id
) publicvirtual{
transferFrom(from, to, id);
require(
to.code.length==0||
ERC721TokenReceiver(to).onERC721Received(msg.sender, from, id, "") ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
functionsafeTransferFrom(addressfrom,
address to,
uint256 id,
bytescalldata data
) publicvirtual{
transferFrom(from, to, id);
require(
to.code.length==0||
ERC721TokenReceiver(to).onERC721Received(msg.sender, from, id, data) ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
/*//////////////////////////////////////////////////////////////
ERC165 LOGIC
//////////////////////////////////////////////////////////////*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualreturns (bool) {
return
interfaceId ==0x01ffc9a7||// ERC165 Interface ID for ERC165
interfaceId ==0x80ac58cd||// ERC165 Interface ID for ERC721
interfaceId ==0x5b5e139f; // ERC165 Interface ID for ERC721Metadata
}
/*//////////////////////////////////////////////////////////////
INTERNAL MINT/BURN LOGIC
//////////////////////////////////////////////////////////////*/function_mint(address to, uint256 id) internalvirtual{
require(to !=address(0), "INVALID_RECIPIENT");
require(_ownerOf[id] ==address(0), "ALREADY_MINTED");
// Counter overflow is incredibly unrealistic.unchecked {
_balanceOf[to]++;
}
_ownerOf[id] = to;
emit Transfer(address(0), to, id);
}
function_burn(uint256 id) internalvirtual{
address owner = _ownerOf[id];
require(owner !=address(0), "NOT_MINTED");
// Ownership check above ensures no underflow.unchecked {
_balanceOf[owner]--;
}
delete _ownerOf[id];
delete getApproved[id];
emit Transfer(owner, address(0), id);
}
/*//////////////////////////////////////////////////////////////
INTERNAL SAFE MINT LOGIC
//////////////////////////////////////////////////////////////*/function_safeMint(address to, uint256 id) internalvirtual{
_mint(to, id);
require(
to.code.length==0||
ERC721TokenReceiver(to).onERC721Received(msg.sender, address(0), id, "") ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
function_safeMint(address to,
uint256 id,
bytesmemory data
) internalvirtual{
_mint(to, id);
require(
to.code.length==0||
ERC721TokenReceiver(to).onERC721Received(msg.sender, address(0), id, data) ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
}
/// @notice A generic interface for a contract which properly accepts ERC721 tokens./// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC721.sol)abstractcontractERC721TokenReceiver{
functiononERC721Received(address,
address,
uint256,
bytescalldata) externalvirtualreturns (bytes4) {
return ERC721TokenReceiver.onERC721Received.selector;
}
}
Contract Source Code
File 2 of 9: ERC721Enumerable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)pragmasolidity ^0.8.0;import"./PVERC721.sol";
import"@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/abstractcontractERC721EnumerableisPVERC721{
// Mapping from owner to list of owned token IDsmapping(address=>mapping(uint256=>uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens listmapping(uint256=>uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumerationuint256[] private _allTokens;
// Mapping from token id to position in the allTokens arraymapping(uint256=>uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverride(ERC721) returns (bool) {
return interfaceId ==type(IERC721Enumerable).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/functiontokenOfOwnerByIndex(address owner, uint256 index) publicviewvirtualreturns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/functiontotalSupply() publicviewvirtualreturns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/functiontokenByIndex(uint256 index) publicviewvirtualreturns (uint256) {
require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
return _allTokens[index];
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* 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, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/functiontransferFrom(addressfrom, address to, uint256 id) publicoverride{
_beforeTokenTransfer(from, to, id);
super.transferFrom(from, to, id);
}
function_mint(address to, uint256 id) internaloverride{
_beforeTokenTransfer(address(0), to, id);
super._mint(to, id);
}
function_burn(uint256 id) internaloverride{
_beforeTokenTransfer(_ownerOf[id], address(0), id);
super._burn(id);
}
function_beforeTokenTransfer(addressfrom,
address to,
uint256 tokenId
) internalvirtual{
if (from==address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} elseif (from!= to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to ==address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} elseif (to !=from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/function_addTokenToOwnerEnumeration(address to, uint256 tokenId) private{
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/function_addTokenToAllTokensEnumeration(uint256 tokenId) private{
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/function_removeTokenFromOwnerEnumeration(addressfrom, uint256 tokenId) private{
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and// then delete the last slot (swap and pop).uint256 lastTokenIndex = ERC721.balanceOf(from) -1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessaryif (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the arraydelete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/function_removeTokenFromAllTokensEnumeration(uint256 tokenId) private{
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and// then delete the last slot (swap and pop).uint256 lastTokenIndex = _allTokens.length-1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding// an 'if' statement (like in _removeTokenFromOwnerEnumeration)uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index// This also deletes the contents at the last position of the arraydelete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
Contract Source Code
File 3 of 9: 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 4 of 9: IERC721.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.6.0) (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`.
*
* 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;
/**
* @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 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 the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (bool);
}
Contract Source Code
File 5 of 9: IERC721Enumerable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)pragmasolidity ^0.8.0;import"../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/interfaceIERC721EnumerableisIERC721{
/**
* @dev Returns the total amount of tokens stored by the contract.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/functiontokenOfOwnerByIndex(address owner, uint256 index) externalviewreturns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/functiontokenByIndex(uint256 index) externalviewreturns (uint256);
}