Question

I have a structure that I would like to make the variables related to each other. Here is a snippet of the code:

struct RSI
{
     int RSI;
     int ESI = RSI & 0x1F;
     int SI = ESI & 0x0F;
     int SIL = SI & 0x08;
};

Is there a way to do this in C, without having to create functions to modify the variables?

Answer 1

No, you would need to define functions to do that.

In C++, you could of course encapsulate the details:

struct RSI
{
private:
    int rsi;

public:
    RSI(int rsi) : rsi(rsi) {}

    int getRSI() const { return rsi; }
    int getESI() const { return getRSI() & 0x1F; }
    int getSI()  const { return getESI() & 0x0F; }
    int getSIL() const { return getSI()  & 0x08; }
};