Compiler Error CS0720
'static class': cannot declare indexers in a static class
Indexers are not meaningful in static classes, since they can only be used with instances, and it is not possible to create instances of a static type.
Example
The following sample generates CS0720:
// CS0720.cs
public static class Test
{
public int this[int index] // CS0720
{
get { return 1; }
set {}
}
static void Main() {}
}