Value types of variable size
- by YellPika
I'm trying to code a small math library in C#. I wanted to create a generic vector structure where the user could define the element type (int, long, float, double, etc.) and dimensions.
My first attempt was something like this...
public struct Vector<T>
{
public readonly int Dimensions;
public readonly T[] Elements;
// etc...
}
Unfortunately, Elements, being an array, is also a reference type. Thus, doing this,
Vector<int> a = ...;
Vector<int> b = a;
a[0] = 1;
b[0] = 2;
would result in both a[0] and b[0] equaling 2.
My second attempt was to define an interface IVector<T>, and then use Reflection.Emit to automatically generate the appropriate type at runtime. The resulting classes would look roughly like this:
public struct Int32Vector3 : IVector<T>
{
public int Element0;
public int Element1;
public int Element2;
public int Dimensions { get { return 3; } }
// etc...
}
This seemed fine until I found out that interfaces seem to act like references to the underlying object. If I passed an IVector to a function, and changes to the elements in the function would be reflected in the original vector.
What I think is my problem here is that I need to be able to create classes that have a user specified number of fields. I can't use arrays, and I can't use inheritance.
Does anyone have a solution?
EDIT: This library is going to be used in performance critical situations, so reference types are not an option.
