Thread: Need help with basic C DLL

Hello, I'm not sure what I'm doing (i study math/physics not CS) and need some help. I am trying to write a DLL in C such that I can pass in two parameters and return a double. Here is the code:

Code:

#pragma once
#include <stdio.h>
#define DLLF _declspec(dllexport)

DLLF double FractalPriceReturn(double price, bool frac)
    {
        double fracprice = price;
        bool fracflag = frac;
        if (fracflag == 2)
        {
            return fracprice;
        }
        else return 0;
    }

////////

The software (a neural network) I'm using to call the DLL selects the file (the DLL) that I want to use but as soon as I do that it crashes my neural network software. Am I saving the program incorrectly? The code is built in VS. Is there something wrong with my code? (It's been a while). Thanks for any responses.

Hello,

Isn't a bool just true or false?

Regards

Would you mind elaborating on "crashes my neural network"? Are you able to compile and successfully link against your DLL?

Originally Posted by mad-hatter

Hello,

Isn't a bool just true or false?

Regards

Also, this. You're declaring a bool and then comparing it to the number two which will never be equal. Ever. In fact, you shouldn't even be doing such mismatched typed comparisons. I suggest you turn up your compiler warnings.

I just need to see the structure/syntax in C, of what a DLL looks like that takes 2 parameters and returns a value. Could be adding two numbers, that would work just fine. THanks