C# in Depth

Advanced generics87within another, and types with multiple generic parameters. This sounds a lot morecomplicated, but it works as you probably think it should. Listing 3.8 shows this inaction, this time using static constructors to show just how many types there are.Listing 3.8Static constructors with nested generic typesNote!Only 5 linesof output…public class Outer{public class Inner{static Inner(){Console.WriteLine("Outer.Inner",typeof(T).Name,typeof(U).Name,typeof(V).Name);}public static void DummyMethod(){}}}...Outer.Inner.DummyMethod();Outer.Inner.DummyMethod();Outer.Inner.DummyMethod();Outer.Inner.DummyMethod();Outer.Inner.DummyMethod();Outer.Inner.DummyMethod();Each different list of type arguments counts as a different closed type, sothe output of listing 3.8 looks like this:Outer.InnerOuter.InnerOuter.InnerOuter.InnerOuter.InnerJust as with nongeneric types, the static constructor for any closed type is only executedonce, which is why the last line of listing 3.8 doesn’t create a sixth line of output—thestatic constructor for Outer.Inner executed earlier,producing the second line of output. To clear up any doubts, if we had a nongenericPlainInner class inside Outer, there would still have been one possibleOuter.PlainInner type per closed Outer type, so Outer.PlainInner wouldbe separate from Outer.PlainInner, with a separate set of static fields asseen earlier.Now that we’ve seen just what constitutes a different type, we should think aboutwhat the effects of that might be in terms of the amount of native code generated.And no, it’s not as bad as you might think…Licensed to Rhona Hadida