Functions as arguments

Is there a way to have functions as arguments? If I have a function that takes a double and returns a double, is there a way I can make another function that takes the first function as an argument?

Code:

---

int foo();

int foofoo(int var);

int main()
{
    int a = foofoo(foo());
    return 0;
}

---

like that?

Yes, for example:

Code:

---

#include <iostream>

double foo(double x);

void bar(double (*func)(double), double x);

int main()
{
    bar(foo, 1.5);
}

double foo(double x)
{
    return x + x;
}

void bar(double (*func)(double), double x)
{
    std::cout << func(x) << std::endl;
}

---

So func in bar is a function pointer, in this case a function pointer to foo. You could also use function objects instead, which can be more powerful.