如何重载*op以乘以常量和单个dim数组成员

所以，我有一个相当具体的问题，我一生都找不到在互联网上引用的。

我想知道如何重载*运算符，这样我就可以在常数和数组的一部分之间相乘。

我的代码，至少是相关的部分，如果需要更多，我可以发布：

    licenseCount licenseCount::operator * (const licenseCount& u) const
    {
        return(this->fxdx*u.fxdx, this->y_array*u.y_array);
    }
    int licenseCount::calc_vol(double z, char *argv[])
    {
        int area;
        std::string y_array[9];
        std::ifstream y_data;
        y_data.open( argv[1] );
        if(y_data.fail())
        {
            std::cout << "Can't open file!n";
            exit(1);
        }
        else
        {
            for(int i=0; i<=9;i++)
            {
                int temp;
                y_data >> y_array[i];
                std::cout << y_array[i] << 'n';
                if(i%2 == 0)
                {
                    temp = 2 * y_array[i];
                    area += fxdx * temp;
                }
                else if(i = 0)
                {
                   area += fxdx * y_array[i];
                }
                else
                {   
                   temp = 4 * y_array[i];
                   area += fxdx * temp;
                }
                std::cout << area;
            }
        vol = area * depth;
        return vol;
    }

我的错误：

licenseCount.cpp:62: error: 'const class licenseCount' has no member named 'y_array'
licenseCount.cpp:62: error: 'const class licenseCount' has no member named 'y_array'
licenseCount.cpp: In member function `int licenseCount::calc_vol(double, char**)':
licenseCount.cpp:90: error: no match for 'operator*' in '2 * y_array[i]'
licenseCount.cpp:91: warning: converting to `int' from `double'
licenseCount.cpp:95: error: no match for 'operator*' in '((licenseCount*)this)-licenseCount::fxdx * y_array[i]'
licenseCount.cpp:98: error: no match for 'operator*' in '4 * y_array[i]'
licenseCount.cpp:99: warning: converting to `int' from `double'
licenseCount.cpp:111: error: a function-definition is not allowed here before '{' token
licenseCount.cpp:113: error: expected `}' at end of input

我在互联网上搜索了很多遍，也许我的搜索词有错误，但我使用了我能想到的每一个单词组合来试图找到答案/叹息

请注意，这是家庭作业，但我们将非常感谢您的解释/帮助！