ERC-888: 多维代币标准 (ERC-888)
ERC-888：
多维代币体系的模型，其使用标识符代表余额和数据。
相关的标准：
EIP-20
EIP-721
非常相关的标准：
ERC-994
ERC-998
ERC-1155
ERC-1178
ERC-1203
ERC1155合约源码
Multi Token Standard：
https://github.com/ethereum/EIPs/issues/1155
验证：
safeTransferFrom(from, to, id, amount, data) //id表示721，标识不同的代币
setApprovalForAll(operator, approved)
pragma solidity ^0.7.1; /** * @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}. */ interface IERC165 { /** * @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 ERC1155 compliant contract, as defined in the * https://eips.ethereum.org/EIPS/eip-1155[EIP]. * * _Available since v3.1._ */ interface IERC1155 is IERC165 { /** * @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 {IERC1155MetadataURI-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:erc1155.adoc#batch-operations[Batched] version of {balanceOf}. * * Requirements: * * - `accounts` and `ids` must have the same length. */ function balanceOfBatch(address[] memory accounts, uint256[] memory 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 {IERC1155Receiver-onERC1155Received} and return the * acceptance magic value. */ function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external; /** * @dev xref:ROOT:erc1155.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 {IERC1155Receiver-onERC1155BatchReceived} and return the * acceptance magic value. */ function safeBatchTransferFrom(address from, address to, uint256[] calldata ids, uint256[] calldata amounts, bytes calldata data) external; } /** * @dev Implementation of the {IERC165} interface. * * Contracts may inherit from this and call {_registerInterface} to declare * their support of an interface. */ contract ERC165 is IERC165 { /* * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7 */ bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7; /** * @dev Mapping of interface ids to whether or not it's supported. */ mapping(bytes4 => bool) private _supportedInterfaces; constructor () { // Derived contracts need only register support for their own interfaces, // we register support for ERC165 itself here _registerInterface(_INTERFACE_ID_ERC165); } /** * @dev See {IERC165-supportsInterface}. * * Time complexity O(1), guaranteed to always use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) public view override returns (bool) { return _supportedInterfaces[interfaceId]; } /** * @dev Registers the contract as an implementer of the interface defined by * `interfaceId`. Support of the actual ERC165 interface is automatic and * registering its interface id is not required. * * See {IERC165-supportsInterface}. * * Requirements: * * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). */ function _registerInterface(bytes4 interfaceId) internal virtual { require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); _supportedInterfaces[interfaceId] = true; } } /** * _Available since v3.1._ */ interface IERC1155Receiver is IERC165 { /** @dev Handles the receipt of a single ERC1155 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("onERC1155Received(address,address,uint256,uint256,bytes)"))` (i.e. 0xf23a6e61, 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("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed */ function onERC1155Received( address operator, address from, uint256 id, uint256 value, bytes calldata data ) external returns(bytes4); /** @dev Handles the receipt of a multiple ERC1155 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("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` (i.e. 0xbc197c81, 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("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed */ function onERC1155BatchReceived( address operator, address from, uint256[] calldata ids, uint256[] calldata values, bytes calldata data ) external returns(bytes4); } /** * @dev _Available since v3.1._ */ abstract contract ERC1155Receiver is ERC165, IERC1155Receiver { constructor() { _registerInterface( ERC1155Receiver(0).onERC1155Received.selector ^ ERC1155Receiver(0).onERC1155BatchReceived.selector ); } } /** * @dev Interface of the optional ERC1155MetadataExtension interface, as defined * in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP]. * * _Available since v3.1._ */ interface IERC1155MetadataURI is IERC1155 { /** * @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 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 GSN 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 payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when an * operation overflows. * * Using this library instead of the unchecked operations eliminates an entire * class of bugs, so it's recommended to use it always. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } /** * @dev Returns the integer division of two unsigned integers. Reverts with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b > 0, errorMessage); uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } /** * @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) { // According to EIP-1052, 0x0 is the value returned for not-yet created accounts // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned // for accounts without code, i.e. `keccak256('')` bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != accountHash && codehash != 0x0); } /** * @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"); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (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"); return _functionCallWithValue(target, data, value, errorMessage); } function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) { require(isContract(target), "Address: call to non-contract"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.call{ value: weiValue }(data); 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 // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } 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 () { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } } /** * * @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/erc-1155 * * _Available since v3.1._ */ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { using SafeMath for uint256; 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; /* * bytes4(keccak256('balanceOf(address,uint256)')) == 0x00fdd58e * bytes4(keccak256('balanceOfBatch(address[],uint256[])')) == 0x4e1273f4 * bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465 * bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5 * bytes4(keccak256('safeTransferFrom(address,address,uint256,uint256,bytes)')) == 0xf242432a * bytes4(keccak256('safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)')) == 0x2eb2c2d6 * * => 0x00fdd58e ^ 0x4e1273f4 ^ 0xa22cb465 ^ * 0xe985e9c5 ^ 0xf242432a ^ 0x2eb2c2d6 == 0xd9b67a26 */ bytes4 private constant _INTERFACE_ID_ERC1155 = 0xd9b67a26; /* * bytes4(keccak256('uri(uint256)')) == 0x0e89341c */ bytes4 private constant _INTERFACE_ID_ERC1155_METADATA_URI = 0x0e89341c; /** * @dev See {_setURI}. */ constructor (string memory uri) { _setURI(uri); // register the supported interfaces to conform to ERC1155 via ERC165 _registerInterface(_INTERFACE_ID_ERC1155); // register the supported interfaces to conform to ERC1155MetadataURI via ERC165 _registerInterface(_INTERFACE_ID_ERC1155_METADATA_URI); } /** * @dev See {IERC1155MetadataURI-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) external view override returns (string memory) { return _uri; } /** * @dev See {IERC1155-balanceOf}. * * Requirements: * * - `account` cannot be the zero address. */ function balanceOf(address account, uint256 id) public view override returns (uint256) { require(account != address(0), "ERC1155: balance query for the zero address"); return _balances[id][account]; } /** * @dev See {IERC1155-balanceOfBatch}. * * Requirements: * * - `accounts` and `ids` must have the same length. */ function balanceOfBatch( address[] memory accounts, uint256[] memory ids ) public view override returns (uint256[] memory) { require(accounts.length == ids.length, "ERC1155: accounts and ids length mismatch"); uint256[] memory batchBalances = new uint256[](accounts.length); for (uint256 i = 0; i < accounts.length; ++i) { require(accounts[i] != address(0), "ERC1155: batch balance query for the zero address"); batchBalances[i] = _balances[ids[i]][accounts[i]]; } return batchBalances; } /** * @dev See {IERC1155-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public virtual override { require(_msgSender() != operator, "ERC1155: setting approval status for self"); _operatorApprovals[_msgSender()][operator] = approved; emit ApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC1155-isApprovedForAll}. */ function isApprovedForAll(address account, address operator) public view override returns (bool) { return _operatorApprovals[account][operator]; } /** * @dev See {IERC1155-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 id, uint256 amount, bytes memory data ) public virtual override { require(to != address(0), "ERC1155: transfer to the zero address"); require( from == _msgSender() || isApprovedForAll(from, _msgSender()), "ERC1155: caller is not owner nor approved" ); address operator = _msgSender(); _beforeTokenTransfer(operator, from, to, _asSingletonArray(id), _asSingletonArray(amount), data); _balances[id][from] = _balances[id][from].sub(amount, "ERC1155: insufficient balance for transfer"); _balances[id][to] = _balances[id][to].add(amount); emit TransferSingle(operator, from, to, id, amount); _doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data); } /** * @dev See {IERC1155-safeBatchTransferFrom}. */ function safeBatchTransferFrom( address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) public virtual override { require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); require(to != address(0), "ERC1155: transfer to the zero address"); require( from == _msgSender() || isApprovedForAll(from, _msgSender()), "ERC1155: transfer caller is not owner nor approved" ); 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]; _balances[id][from] = _balances[id][from].sub( amount, "ERC1155: insufficient balance for transfer" ); _balances[id][to] = _balances[id][to].add(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 `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the * acceptance magic value. */ function _mint(address account, uint256 id, uint256 amount, bytes memory data) internal virtual { require(account != address(0), "ERC1155: mint to the zero address"); address operator = _msgSender(); _beforeTokenTransfer(operator, address(0), account, _asSingletonArray(id), _asSingletonArray(amount), data); _balances[id][account] = _balances[id][account].add(amount); emit TransferSingle(operator, address(0), account, id, amount); _doSafeTransferAcceptanceCheck(operator, address(0), account, id, amount, data); } /** * @dev xref:ROOT:erc1155.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 {IERC1155Receiver-onERC1155BatchReceived} 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), "ERC1155: mint to the zero address"); require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); address operator = _msgSender(); _beforeTokenTransfer(operator, address(0), to, ids, amounts, data); for (uint i = 0; i < ids.length; i++) { _balances[ids[i]][to] = amounts[i].add(_balances[ids[i]][to]); } 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), "ERC1155: burn from the zero address"); address operator = _msgSender(); _beforeTokenTransfer(operator, account, address(0), _asSingletonArray(id), _asSingletonArray(amount), ""); _balances[id][account] = _balances[id][account].sub( amount, "ERC1155: burn amount exceeds balance" ); emit TransferSingle(operator, account, address(0), id, amount); } /** * @dev xref:ROOT:erc1155.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), "ERC1155: burn from the zero address"); require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); address operator = _msgSender(); _beforeTokenTransfer(operator, account, address(0), ids, amounts, ""); for (uint i = 0; i < ids.length; i++) { _balances[ids[i]][account] = _balances[ids[i]][account].sub( amounts[i], "ERC1155: burn amount exceeds balance" ); } 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 IERC1155Receiver(to).onERC1155Received(operator, from, id, amount, data) returns (bytes4 response) { if (response != IERC1155Receiver(to).onERC1155Received.selector) { revert("ERC1155: ERC1155Receiver rejected tokens"); } } catch Error(string memory reason) { revert(reason); } catch { revert("ERC1155: transfer to non ERC1155Receiver implementer"); } } } function _doSafeBatchTransferAcceptanceCheck( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) private { if (to.isContract()) { try IERC1155Receiver(to).onERC1155BatchReceived(operator, from, ids, amounts, data) returns (bytes4 response) { if (response != IERC1155Receiver(to).onERC1155BatchReceived.selector) { revert("ERC1155: ERC1155Receiver rejected tokens"); } } catch Error(string memory reason) { revert(reason); } catch { revert("ERC1155: transfer to non ERC1155Receiver implementer"); } } } function _asSingletonArray(uint256 element) private pure returns (uint256[] memory) { uint256[] memory array = new uint256[](1); array[0] = element; return array; } } contract HMOB is ERC1155,Ownable(){ uint256 id; constructor() public ERC1155("https://www.goldstandardgrp.com/metadata/berlin/HMOR.json") { } function mintToken(address _address,uint256 supply) public onlyOwner { _mint(_address,id,supply,""); id++; } }
参考：https://github.com/shahzaintariq/ERC1155
https://github.com/shahzaintariq/ERC1155/blob/master/contracts/HMOR.sol
