C# Cast Entire Array?

The proposed LINQ solution using Cast/'Select' is fine, but since you know you are working with an array here, using ConvertAll is rather more efficienct, and just as simple.

var newArray = Array.ConvertAll(array, item => (NewType)item);

Using ConvertAll means
a) the array is only iterated over once,
b) the operation is more optimised for arrays (does not use IEnumerator<T>).

Don't let the Converter<TInput, TOutput> type confuse you - it is just a simple delegate, and thus you can pass a lambda expression for it, as shown above.

As an update to this old question, you can now do:

myArray.Cast<Vec2>().ToArray();

where myArray contains the source objects, and Vec2 is the type you want to cast to.

Cast doesn't consider user defined implicit conversions so you can't cast the array like that. You can use select instead:

myArray.Select(p => (Vec2)p).ToArray();

Or write a converter:

Array.ConvertAll(points, (p => (Vec2)p));

The latter is probably more efficient as the size of the result is known in advance.