C++ Function List

Question

I'm working on a fairly complex project, a custom encryption routine if you will (just for fun) and I've run into this issue in designing my code layout.

I have a number of functions that I want to be able to call by index. Specifically, I need to be able to call one randomly for the encrypt process, but then address that by a specific index in the decrypt process.

I was considering a classic function array, but my main concern is that a function array would be tricky to maintain, and a little ugly. (The goal is to get each function pair in a separate file, to reduce compile times and make the code easier to manage.) Does anyone have a more elegant C++ solution as an alternative to a function array? Speed isn't really an issue, I'm more worried about maintainability.

-Nicholas

Answer 1

You could write something like:

class EncryptionFunction
{
public:
    virtual Foo Run(Bar input) = 0;
    virtual ~MyFunction() {}
};

class SomeSpecificEncryptionFunction : public EncryptionFunction
{
    // override the Run function
};

// ...

std::vector<EncryptionFunction*> functions;

// ...

functions[2]->Run(data);

You could use operator() instead of Run as the function name, if you prefer.