I making a method that generate a unique string key for some parameters. But the same key if call with same values.

I just accept primitive types, string, DateTime, Guid, and Nullable(since I append types together, I can distinguish who is int and who is int?), because I can convert all to string without lost values or precision.(for float and double a use ToString("R"), to DateTime ToString("O")).

Exists a easy way to know which types I can transform in strings without conflict? And how do this transform(how I said before, float, double and datetime have specific ways)

Thanks