如何将结构(没有属性，只有方法)传递给三角函数？

#include <iostream>

struct MyStruct {
    double (*func)(double);
};

double square(double x) {
    return x * x;
}

double cube(double x) {
    return x * x * x;
}

void trigonometricFunction(double (*func)(double), double x) {
    double result = func(x);
    std::cout << "The result is: " << result << std::endl;
}

int main() {
    MyStruct myStruct1;
    myStruct1.func = square;
    trigonometricFunction(myStruct1.func, 3.0);

    MyStruct myStruct2;
    myStruct2.func = cube;
    trigonometricFunction(myStruct2.func, 3.0);

    return 0;
}