固定性:从其他智能合约调用修饰符

pragma solidity ^0.8.0;

contract Voting {
    mapping(address => bool) public voters;
    uint256 public voteCost = 100;

    modifier onlyVoter {
        require(voters[msg.sender], "Only registered voters can vote");
        _;
    }

    modifier hasEnoughTokens(uint256 amount) {
        // 假设有一个代币合约的实例 tokenContract
        require(tokenContract.balanceOf(msg.sender) >= amount, "Not enough tokens");
        _;
    }

    function registerVoter(address user) public {
        voters[user] = true;
    }

    function vote() public onlyVoter hasEnoughTokens(voteCost) {
        // 执行投票逻辑
        // ...
    }
}

modifier onlyVoter {
    if (!voters[msg.sender]) {
        revert("Only registered voters can vote");
    }
    _;
}