Why doesn't Array class expose its indexer directly?

Question

something to mention for answering:

1. Don\'t worry about variance, while the item in question is Array rather than

Answer 1

Even if array's were all 1D, you'd still have a Covariance and Contravariance issue:

If the base class had a

public Object this[int index] { get; set; }

indexer property, then the concrete types indexer properties

public TValue this[int index] { get; set; }

would collide with that of the base type (since the parameter is of the setter is the same however the return value isn't).

Casting the base class into either a base interface or a generic interface like either IList or IList solves this, since the non-specific indexer can be implemented explicitly. This is the same with the

Add(Object value)

vs.

Add(TValue value)

methods.

The multi dimensional issue could, theoretically, be overcome by defining a conversion between 1D indexes and n-D indexes (e.g. [n] = [n / length(0), n % length(0)]) since n-D matrices are stored as one continuous buffer.