Contract Example

pragma solidity ^0.8.2;

// SPDX-License-Identifier: MIT
/**

• @dev Interface of the VRC165 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 ({VRC165Checker}).
• For an implementation, see {VRC165}.
  /
  interface IVRC165 {
  /**
  @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.
  /
  function supportsInterface(bytes4 interfaceId) external view returns (bool);
  }

/**

• @dev Required interface of an VRC1155 compliant contract, as defined in the

• https://eips.ethereum.org/EIPS/eip-1155[EIP].

• Available since v3.1.
  /
  interface IVRC1155 is IVRC165 {
  /**
  @dev Emitted when value tokens of token type id are transferred from from to to by operator.
  */
  event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

  /**
   * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
   * transfers.
   */
  event TransferBatch(
      address indexed operator,
      address indexed from,
      address indexed to,
      uint256[] ids,
      uint256[] values
  );
  
  /**
   * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
   * `approved`.
   */
  event ApprovalForAll(address indexed account, address indexed operator, bool approved);
  
  /**
   * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
   *
   * If an {URI} event was emitted for `id`, the standard
   * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
   * returned by {IVRC1155MetadataURI-uri}.
   */
  event URI(string value, uint256 indexed id);
  
  /**
   * @dev Returns the amount of tokens of token type `id` owned by `account`.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   */
  function balanceOf(address account, uint256 id) external view returns (uint256);
  
  /**
   * @dev xref:ROOT:VRC1155.adoc#batch-operations[Batched] version of {balanceOf}.
   *
   * Requirements:
   *
   * - `accounts` and `ids` must have the same length.
   */
  function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
      external
      view
      returns (uint256[] memory);
  
  /**
   * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
   *
   * Emits an {ApprovalForAll} event.
   *
   * Requirements:
   *
   * - `operator` cannot be the caller.
   */
  function setApprovalForAll(address operator, bool approved) external;
  
  /**
   * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
   *
   * See {setApprovalForAll}.
   */
  function isApprovedForAll(address account, address operator) external view returns (bool);
  
  /**
   * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
   *
   * Emits a {TransferSingle} event.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
   * - `from` must have a balance of tokens of type `id` of at least `amount`.
   * - If `to` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155Received} and return the
   * acceptance magic value.
   */
  function safeTransferFrom(
      address from,
      address to,
      uint256 id,
      uint256 amount,
      bytes calldata data
  ) external;
  
  /**
   * @dev xref:ROOT:VRC1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
   *
   * Emits a {TransferBatch} event.
   *
   * Requirements:
   *
   * - `ids` and `amounts` must have the same length.
   * - If `to` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155BatchReceived} and return the
   * acceptance magic value.
   */
  function safeBatchTransferFrom(
      address from,
      address to,
      uint256[] calldata ids,
      uint256[] calldata amounts,
      bytes calldata data
  ) external;
  

  }

/**

• @dev Available since v3.1.
  /
  interface IVRC1155Receiver is IVRC165 {
  /**
  @dev Handles the receipt of a single VRC1155 token type. This function is
  called at the end of a safeTransferFrom after the balance has been updated.
  To accept the transfer, this must return
  bytes4(keccak256("onVRC1155Received(address,address,uint256,uint256,bytes)"))
  (i.e. 0xd37fbeb1, or its own function selector).
  @param operator The address which initiated the transfer (i.e. msg.sender)
  @param from The address which previously owned the token
  @param id The ID of the token being transferred
  @param value The amount of tokens being transferred
  @param data Additional data with no specified format
  @return bytes4(keccak256("onVRC1155Received(address,address,uint256,uint256,bytes)")) if transfer is allowed
  /
  function onVRC1155Received(
  address operator,
  address from,
  uint256 id,
  uint256 value,
  bytes calldata data
  ) external returns (bytes4);

  /**
      @dev Handles the receipt of a multiple VRC1155 token types. This function
      is called at the end of a `safeBatchTransferFrom` after the balances have
      been updated. To accept the transfer(s), this must return
      `bytes4(keccak256("onVRC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
      (i.e. 0xa4f0a8c7, or its own function selector).
      @param operator The address which initiated the batch transfer (i.e. msg.sender)
      @param from The address which previously owned the token
      @param ids An array containing ids of each token being transferred (order and length must match values array)
      @param values An array containing amounts of each token being transferred (order and length must match ids array)
      @param data Additional data with no specified format
      @return `bytes4(keccak256("onVRC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
  */
  function onVRC1155BatchReceived(
      address operator,
      address from,
      uint256[] calldata ids,
      uint256[] calldata values,
      bytes calldata data
  ) external returns (bytes4);
  

  }

/**

• @dev Interface of the optional VRC1155MetadataExtension interface, as defined
• in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP].
• Available since v3.1.
  /
  interface IVRC1155MetadataURI is IVRC1155 {
  /**
  @dev Returns the URI for token type id.
  *
  If the \{id\} substring is present in the URI, it must be replaced by
  clients with the actual token type ID.
  */
  function uri(uint256 id) external view returns (string memory);
  }

/**

• @dev Collection of functions related to the address type
  /
  library Address {
  /**
  @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
  ====
  /
  function isContract(address account) internal view returns (bool) {
  // This method relies on extcodesize, which returns 0 for contracts in
  // construction, since the code is only stored at the end of the
  // constructor execution.

      uint256 size;
      assembly {
          size := extcodesize(account)
      }
      return size > 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].
   */
  function sendValue(address payable 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._
   */
  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      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._
   */
  function functionCall(
      address target,
      bytes memory data,
      string memory errorMessage
  ) internal returns (bytes memory) {
      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._
   */
  function functionCallWithValue(
      address target,
      bytes memory data,
      uint256 value
  ) internal returns (bytes memory) {
      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._
   */
  function functionCallWithValue(
      address target,
      bytes memory data,
      uint256 value,
      string memory errorMessage
  ) internal returns (bytes memory) {
      require(address(this).balance >= value, "Address: insufficient balance for call");
      require(isContract(target), "Address: call to non-contract");
  
      (bool success, bytes memory 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._
   */
  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
      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._
   */
  function functionStaticCall(
      address target,
      bytes memory data,
      string memory errorMessage
  ) internal view returns (bytes memory) {
      require(isContract(target), "Address: static call to non-contract");
  
      (bool success, bytes memory 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._
   */
  function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
      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._
   */
  function functionDelegateCall(
      address target,
      bytes memory data,
      string memory errorMessage
  ) internal returns (bytes memory) {
      require(isContract(target), "Address: delegate call to non-contract");
  
      (bool success, bytes memory 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._
   */
  function verifyCallResult(
      bool success,
      bytes memory returndata,
      string memory errorMessage
  ) internal pure returns (bytes memory) {
      if (success) {
          return returndata;
      } else {
          // Look for revert reason and bubble it up if present
          if (returndata.length > 0) {
              // The easiest way to bubble the revert reason is using memory via assembly
  
              assembly {
                  let returndata_size := mload(returndata)
                  revert(add(32, returndata), returndata_size)
              }
          } else {
              revert(errorMessage);
          }
      }
  }
  

  }

/**

• @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.
  */
  abstract contract Context {
  function _msgSender() internal view virtual returns (address) {
  return msg.sender;
  }

  function _msgData() internal view virtual returns (bytes calldata) {
      return msg.data;
  }
  

  }

/**

• @dev Implementation of the {IVRC165} interface.
• Contracts that want to implement VRC165 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, {VRC165Storage} provides an easier to use but more expensive implementation.
  /
  abstract contract VRC165 is IVRC165 {
  /**
  @dev See {IVRC165-supportsInterface}.
  */
  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
  return interfaceId == type(IVRC165).interfaceId;
  }
  }

/**

• @dev Implementation of the basic standard multi-token.

• See https://eips.ethereum.org/EIPS/eip-1155

• Originally based on code by Enjin: https://github.com/enjin/VRC-1155

• Available since v3.1.
  */
  contract VRC1155 is Context, VRC165, IVRC1155, IVRC1155MetadataURI {
  using Address for address;

  // Mapping from token ID to account balances
  mapping(uint256 => mapping(address => uint256)) private _balances;
  
  // Mapping from account to operator approvals
  mapping(address => mapping(address => bool)) private _operatorApprovals;
  
  // Used as the URI for all token types by relying on ID substitution, e.g. https://token-cdn-domain/{id}.json
  string private _uri;
  
  /**
   * @dev See {_setURI}.
   */
  constructor(string memory uri_) {
      _setURI(uri_);
  }
  
  /**
   * @dev See {IVRC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId) public view virtual override(VRC165, IVRC165) returns (bool) {
      return
          interfaceId == type(IVRC1155).interfaceId ||
          interfaceId == type(IVRC1155MetadataURI).interfaceId ||
          super.supportsInterface(interfaceId);
  }
  
  /**
   * @dev See {IVRC1155MetadataURI-uri}.
   *
   * This implementation returns the same URI for *all* token types. It relies
   * on the token type ID substitution mechanism
   * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
   *
   * Clients calling this function must replace the `\{id\}` substring with the
   * actual token type ID.
   */
  function uri(uint256) public view virtual override returns (string memory) {
      return _uri;
  }
  
  /**
   * @dev See {IVRC1155-balanceOf}.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   */
  function balanceOf(address account, uint256 id) public view virtual override returns (uint256) {
      require(account != address(0), "VRC1155: balance query for the zero address");
      return _balances[id][account];
  }
  
  /**
   * @dev See {IVRC1155-balanceOfBatch}.
   *
   * Requirements:
   *
   * - `accounts` and `ids` must have the same length.
   */
  function balanceOfBatch(address[] memory accounts, uint256[] memory ids)
      public
      view
      virtual
      override
      returns (uint256[] memory)
  {
      require(accounts.length == ids.length, "VRC1155: accounts and ids length mismatch");
  
      uint256[] memory batchBalances = new uint256[](accounts.length);
  
      for (uint256 i = 0; i < accounts.length; ++i) {
          batchBalances[i] = balanceOf(accounts[i], ids[i]);
      }
  
      return batchBalances;
  }
  
  /**
   * @dev See {IVRC1155-setApprovalForAll}.
   */
  function setApprovalForAll(address operator, bool approved) public virtual override {
      require(_msgSender() != operator, "VRC1155: setting approval status for self");
  
      _operatorApprovals[_msgSender()][operator] = approved;
      emit ApprovalForAll(_msgSender(), operator, approved);
  }
  
  /**
   * @dev See {IVRC1155-isApprovedForAll}.
   */
  function isApprovedForAll(address account, address operator) public view virtual override returns (bool) {
      return _operatorApprovals[account][operator];
  }
  
  /**
   * @dev See {IVRC1155-safeTransferFrom}.
   */
  function safeTransferFrom(
      address from,
      address to,
      uint256 id,
      uint256 amount,
      bytes memory data
  ) public virtual override {
      require(
          from == _msgSender() || isApprovedForAll(from, _msgSender()),
          "VRC1155: caller is not owner nor approved"
      );
      _safeTransferFrom(from, to, id, amount, data);
  }
  
  /**
   * @dev See {IVRC1155-safeBatchTransferFrom}.
   */
  function safeBatchTransferFrom(
      address from,
      address to,
      uint256[] memory ids,
      uint256[] memory amounts,
      bytes memory data
  ) public virtual override {
      require(
          from == _msgSender() || isApprovedForAll(from, _msgSender()),
          "VRC1155: transfer caller is not owner nor approved"
      );
      _safeBatchTransferFrom(from, to, ids, amounts, data);
  }
  
  /**
   * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
   *
   * Emits a {TransferSingle} event.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - `from` must have a balance of tokens of type `id` of at least `amount`.
   * - If `to` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155Received} and return the
   * acceptance magic value.
   */
  function _safeTransferFrom(
      address from,
      address to,
      uint256 id,
      uint256 amount,
      bytes memory data
  ) internal virtual {
      require(to != address(0), "VRC1155: transfer to the zero address");
  
      address operator = _msgSender();
  
      _beforeTokenTransfer(operator, from, to, _asSingletonArray(id), _asSingletonArray(amount), data);
  
      uint256 fromBalance = _balances[id][from];
      require(fromBalance >= amount, "VRC1155: insufficient balance for transfer");
      unchecked {
          _balances[id][from] = fromBalance - amount;
      }
      _balances[id][to] += amount;
  
      emit TransferSingle(operator, from, to, id, amount);
      _doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data);
  }
  
  /**
   * @dev xref:ROOT:VRC1155.adoc#batch-operations[Batched] version of {_safeTransferFrom}.
   *
   * Emits a {TransferBatch} event.
   *
   * Requirements:
   *
   * - If `to` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155BatchReceived} and return the
   * acceptance magic value.
   */
  function _safeBatchTransferFrom(
      address from,
      address to,
      uint256[] memory ids,
      uint256[] memory amounts,
      bytes memory data
  ) internal virtual {
      require(ids.length == amounts.length, "VRC1155: ids and amounts length mismatch");
      require(to != address(0), "VRC1155: transfer to the zero address");
  
      address operator = _msgSender();
      _beforeTokenTransfer(operator, from, to, ids, amounts, data);
  
      for (uint256 i = 0; i < ids.length; ++i) {
          uint256 id = ids[i];
          uint256 amount = amounts[i];
  
          uint256 fromBalance = _balances[id][from];
          require(fromBalance >= amount, "VRC1155: insufficient balance for transfer");
          unchecked {
              _balances[id][from] = fromBalance - amount;
          }
          _balances[id][to] += amount;
      }
  
      emit TransferBatch(operator, from, to, ids, amounts);
      _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, amounts, data);
  }
  
  /**
   * @dev Sets a new URI for all token types, by relying on the token type ID
   * substitution mechanism
   * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
   *
   * By this mechanism, any occurrence of the `\{id\}` substring in either the
   * URI or any of the amounts in the JSON file at said URI will be replaced by
   * clients with the token type ID.
   *
   * For example, the `https://token-cdn-domain/\{id\}.json` URI would be
   * interpreted by clients as
   * `https://token-cdn-domain/000000000000000000000000000000000000000000000000000000000004cce0.json`
   * for token type ID 0x4cce0.
   *
   * See {uri}.
   *
   * Because these URIs cannot be meaningfully represented by the {URI} event,
   * this function emits no events.
   */
  function _setURI(string memory newuri) internal virtual {
      _uri = newuri;
  }
  
  /**
   * @dev Creates `amount` tokens of token type `id`, and assigns them to `account`.
   *
   * Emits a {TransferSingle} event.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   * - If `account` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155Received} and return the
   * acceptance magic value.
   */
  function _mint(
      address account,
      uint256 id,
      uint256 amount,
      bytes memory data
  ) internal virtual {
      require(account != address(0), "VRC1155: mint to the zero address");
  
      address operator = _msgSender();
  
      _beforeTokenTransfer(operator, address(0), account, _asSingletonArray(id), _asSingletonArray(amount), data);
  
      _balances[id][account] += amount;
      emit TransferSingle(operator, address(0), account, id, amount);
      _doSafeTransferAcceptanceCheck(operator, address(0), account, id, amount, data);
  }
  
  /**
   * @dev xref:ROOT:VRC1155.adoc#batch-operations[Batched] version of {_mint}.
   *
   * Requirements:
   *
   * - `ids` and `amounts` must have the same length.
   * - If `to` refers to a smart contract, it must implement {IVRC1155Receiver-onVRC1155BatchReceived} and return the
   * acceptance magic value.
   */
  function _mintBatch(
      address to,
      uint256[] memory ids,
      uint256[] memory amounts,
      bytes memory data
  ) internal virtual {
      require(to != address(0), "VRC1155: mint to the zero address");
      require(ids.length == amounts.length, "VRC1155: ids and amounts length mismatch");
  
      address operator = _msgSender();
  
      _beforeTokenTransfer(operator, address(0), to, ids, amounts, data);
  
      for (uint256 i = 0; i < ids.length; i++) {
          _balances[ids[i]][to] += amounts[i];
      }
  
      emit TransferBatch(operator, address(0), to, ids, amounts);
      _doSafeBatchTransferAcceptanceCheck(operator, address(0), to, ids, amounts, data);
  }
  
  /**
   * @dev Destroys `amount` tokens of token type `id` from `account`
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   * - `account` must have at least `amount` tokens of token type `id`.
   */
  function _burn(
      address account,
      uint256 id,
      uint256 amount
  ) internal virtual {
      require(account != address(0), "VRC1155: burn from the zero address");
  
      address operator = _msgSender();
  
      _beforeTokenTransfer(operator, account, address(0), _asSingletonArray(id), _asSingletonArray(amount), "");
  
      uint256 accountBalance = _balances[id][account];
      require(accountBalance >= amount, "VRC1155: burn amount exceeds balance");
      unchecked {
          _balances[id][account] = accountBalance - amount;
      }
      emit TransferSingle(operator, account, address(0), id, amount);
  }
  
  /**
   * @dev xref:ROOT:VRC1155.adoc#batch-operations[Batched] version of {_burn}.
   *
   * Requirements:
   *
   * - `ids` and `amounts` must have the same length.
   */
  function _burnBatch(
      address account,
      uint256[] memory ids,
      uint256[] memory amounts
  ) internal virtual {
      require(account != address(0), "VRC1155: burn from the zero address");
      require(ids.length == amounts.length, "VRC1155: ids and amounts length mismatch");
  
      address operator = _msgSender();
  
      _beforeTokenTransfer(operator, account, address(0), ids, amounts, "");
  
      for (uint256 i = 0; i < ids.length; i++) {
          uint256 id = ids[i];
          uint256 amount = amounts[i];
  
          uint256 accountBalance = _balances[id][account];
          require(accountBalance >= amount, "VRC1155: burn amount exceeds balance");
          unchecked {
              _balances[id][account] = accountBalance - amount;
          }
      }
      emit TransferBatch(operator, account, address(0), ids, amounts);
  }
  
  /**
   * @dev Hook that is called before any token transfer. This includes minting
   * and burning, as well as batched variants.
   *
   * The same hook is called on both single and batched variants. For single
   * transfers, the length of the `id` and `amount` arrays will be 1.
   *
   * Calling conditions (for each `id` and `amount` pair):
   *
   * - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * of token type `id` will be  transferred to `to`.
   * - When `from` is zero, `amount` tokens of token type `id` will be minted
   * for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens of token type `id`
   * will be burned.
   * - `from` and `to` are never both zero.
   * - `ids` and `amounts` have the same, non-zero length.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(
      address operator,
      address from,
      address to,
      uint256[] memory ids,
      uint256[] memory amounts,
      bytes memory data
  ) internal virtual {}
  
  function _doSafeTransferAcceptanceCheck(
      address operator,
      address from,
      address to,
      uint256 id,
      uint256 amount,
      bytes memory data
  ) private {
      if (to.isContract()) {
          try IVRC1155Receiver(to).onVRC1155Received(operator, from, id, amount, data) returns (bytes4 response) {
              if (response != IVRC1155Receiver.onVRC1155Received.selector) {
                  revert("VRC1155: VRC1155Receiver rejected tokens");
              }
          } catch Error(string memory reason) {
              revert(reason);
          } catch {
              revert("VRC1155: transfer to non VRC1155Receiver implementer");
          }
      }
  }
  
  function _doSafeBatchTransferAcceptanceCheck(
      address operator,
      address from,
      address to,
      uint256[] memory ids,
      uint256[] memory amounts,
      bytes memory data
  ) private {
      if (to.isContract()) {
          try IVRC1155Receiver(to).onVRC1155BatchReceived(operator, from, ids, amounts, data) returns (
              bytes4 response
          ) {
              if (response != IVRC1155Receiver.onVRC1155BatchReceived.selector) {
                  revert("VRC1155: VRC1155Receiver rejected tokens");
              }
          } catch Error(string memory reason) {
              revert(reason);
          } catch {
              revert("VRC1155: transfer to non VRC1155Receiver implementer");
          }
      }
  }
  
  function _asSingletonArray(uint256 element) private pure returns (uint256[] memory) {
      uint256[] memory array = new uint256[](1);
      array[0] = element;
  
      return array;
  }
  

  }

/**

• @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.
  */
  abstract contract Ownable is Context {
  address private _owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
  /**
   * @dev Initializes the contract setting the deployer as the initial owner.
   */
  constructor() {
      _setOwner(_msgSender());
  }
  
  /**
   * @dev Returns the address of the current owner.
   */
  function owner() public view virtual returns (address) {
      return _owner;
  }
  
  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
      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.
   */
  function renounceOwnership() public virtual onlyOwner {
      _setOwner(address(0));
  }
  
  /**
   * @dev Transfers ownership of the contract to a new account (`newOwner`).
   * Can only be called by the current owner.
   */
  function transferOwnership(address newOwner) public virtual onlyOwner {
      require(newOwner != address(0), "Ownable: new owner is the zero address");
      _setOwner(newOwner);
  }
  
  function _setOwner(address newOwner) private {
      address oldOwner = _owner;
      _owner = newOwner;
      emit OwnershipTransferred(oldOwner, newOwner);
  }
  

  }

contract VrcToken1155 is VRC1155, Ownable {
constructor() VRC1155("https://token-cdn-domain/{id}.json") {}

function setURI(string memory newuri) public onlyOwner {
    _setURI(newuri);
}

function mint(address account, uint256 id, uint256 amount, bytes memory data)
    public
    onlyOwner
{
    _mint(account, id, amount, data);
}

function mintBatch(address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data)
    public
    onlyOwner
{
    _mintBatch(to, ids, amounts, data);
}

}