ERC-7196: 简单 Token，简化版 ERC-20

pragma solidity ^0.8.20;

/**
 * @title ERC7196 Simple token interface
 * @dev See https://ercs.ethereum.org/ERCS/erc-7196
 */
interface IERC7196 {
    /**
     * @notice Used to notify transfer tokens.
     * @param from Address of the from
     * @param to Address of the receive
     * @param value The transaction amount
     */
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );
	
    /**
     * @notice Get the total supply
     * @return total The total supply amount
     */
    function totalSupply() 
        external  
        view
        returns (uint256 total);
	  
    /**
     * @notice get the balance of owenr address
     * @param owner Address of the owner
     * @return balance The balance of the owenr address
     */
    function balanceOf(address owner) 
        external
        view
        returns (uint256 balance);

    /**
     * @notice Transfer token
     * @param to Address of the to
     * @param value The transaction amount
     * @return success The bool value returns whether the transfer is successful
     */
    function transfer(address to, uint256 value)
        external
        returns (bool success);

}

pragma solidity ^0.8.20;

import "./IERC7196.sol";
import "../../math/SafeMath.sol";

/**
 * @title Standard ERC7196 token
 * @dev Note: the ERC-165 identifier for this interface is 0xc1b31357
 * @dev Implementation of the basic standard token.
 */
contract ERC7196 is IERC7196 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    uint256 private _totalSupply;

    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address owner) external view returns (uint256) {
        return _balances[owner];
    }

    function transfer(address to, uint256 value) external returns (bool) {
        require(value <= _balances[msg.sender]);
        require(to != address(0));

        _balances[msg.sender] = _balances[msg.sender].sub(value);
        _balances[to] = _balances[to].add(value);
        emit Transfer(msg.sender, to, value);
        return true;
    }

}