Safe (in the C# sense) way to implement something with pointers

Question

            ...
            {
                int *r1, *r2;
                r1 = GetCorrectRegister(first);
                r2 = GetCorrectRegister(second);
                switch ((OpCode)current.opcode)
                {
                    case OpCode.ADDR:
                        r2 = r1 + r2;
                        break;
                }
            }
            ...

This is the obvious, easiest way to solve this problem. However, I'd prefer not to use an unsafe method if I can avoid it. Basically, I have a bunch of integers which represent registers. There are assembly instructions that take register mnemonics as arguments. I'd prefer not to have the logic to determine which variable to assign to in each branch of the switch statement or make some sort of kludgey GetRegisterValue(mnemonic) and SetRegisterValue(mnemonic) functions. Is there some C#y way to do something similar?

Answer 1

I have a bunch of integers which represent registers

The obvious thing here is not to have a bunch of integers. Create an array

 int[] registers = new int[NUMBER_OF_REGISTERS];

Your above code turns into

    {
            int r1Index, r2Index;
            r1Index = GetCorrectRegisterIndex(first);
            r2Index = GetCorrectRegisterIndex(second);
            switch ((OpCode)current.opcode)
            {
                case OpCode.ADDR:
                    registers[r1Index] = registers[r1Index] + registers[r2Index];
                    break;
            }


     }

Additionally, use an enum to create symbolic names for your register names where each name gives you the right index.