Nested function alternatives in C++

Question

I want to make a function f() that uses three values to compute its result: a, b, and e. e is dependent on a and b, so technically f() is only a function of a and b. But for the sake of readability, it is easier to look at a function containing the abstraction e than to look at a messier formula containing many a's and b's.

Is there any way to use dependent variables like e without the use of nested functions, which C++ does not allow?

Answer 1

C++ does have local variables, which makes this easy:

double f(double const a, double const b)
{
    double const e = a * b + b * b * b;
    return a + b + e;
}