当未使用时，如何在返回变量中沉默警告？

Question

我在solidity中有以下函数：

function validateAndPayForPaymasterTransaction(
    bytes32, 
    bytes32, 
    Transaction calldata _transaction
) external payable override onlyBootloader returns (bytes4 magic, bytes memory context) {
    require(
        _transaction.paymasterInput.length >= 4,
        "The standard paymaster input must be at least 4 bytes long"
    );

    bytes4 paymasterInputSelector = bytes4(
        _transaction.paymasterInput[0:4]
    );
    if (paymasterInputSelector == IPaymasterFlow.approvalBased.selector) {
        (address token, uint256 minAllowance, ) = abi
            .decode(
                _transaction.paymasterInput[4:],
                (address, uint256, bytes)
            );

        require(token == allowedToken, "Invalid token");
        require(minAllowance >= 1, "Min allowance too low");

        address userAddress = address(uint160(_transaction.from));
        address thisAddress = address(this);

        uint256 providedAllowance = IERC20(token).allowance(
            userAddress,
            thisAddress
        );
        require(
            providedAllowance >= PRICE_FOR_PAYING_FEES,
            "The user did not provide enough allowance"
        );

        // Note, that while the minimal amount of ETH needed is tx.gasPrice * tx.gasLimit,
        // neither paymaster nor account are allowed to access this context variable.
        uint256 requiredETH = _transaction.gasLimit *
            _transaction.maxFeePerGas;

        // Pulling all the tokens from the user
        IERC20(token).transferFrom(userAddress, thisAddress, 1);
        // The bootloader never returns any data, so it can safely be ignored here.
        (bool success, ) = payable(BOOTLOADER_FORMAL_ADDRESS).call{
            value: requiredETH
        }("");
        require(success, "Failed to transfer funds to the bootloader");
    } else {
        revert("Unsupported paymaster flow");
    }
}

在从函数(bytes4 magic, bytes memory context)返回的两个变量中，我得到了这些警告：

Unused function parameter. Remove or comment out the variable name to silence this warning.

我怎么才能沉默这个警告呢？我实际上不能删除变量，因为它们是覆盖函数的一部分。如果我这样做，我会得到以下信息：

Overriding function return types differ.

Answer 1

这些警告的解决办法是：

按照return语句的建议，从舒班斯卡特尔语句中删除变量的名称：

function validateAndPayForPaymasterTransaction(
    bytes32, 
    bytes32, 
    Transaction calldata _transaction
) external payable override onlyBootloader returns (bytes4, bytes memory)

然后确保在代码的每个return中返回上述值类型(所有不恢复代码路径)：

return (paymasterInputSelector, bytesVariable);

在本例中，paymasterInputSelector为bytes4类型，bytesVariable为bytes类型。

注意-声明如下所示的bytes变量：

        bytes memory bytesVariable = new bytes(0);