Annoying Void in C# / Java / alike

By gamlerhart January 12, 2012 .NET, java

One thing which regularly annoys me in C# and Java is the void type. Basically the void type is not a subtype of object, which makes it giant. Now when you write something which accepts a function as an argument you need two version: A version which accepts a function which returns something and a version which accepts a ‘void-returning’-function (the Action delegates in C#).

Void Is Not Cool Enough

In my code I often end up doing something like this:

class Example { // Stuff like transactions, run in contexts, binding methods etc etc. public T WithSomeContext<T>(Func<T> runInContext) { // do magic and stuff var result = runInContext(); // do other stuff return result; } // Doublicate to also accept Void returns public void WithSomeContext(Action runInContext) { WithSomeContext<object>(() => { runInContext(); return null; }); } public void UseIt() { var valueOne = 1; var valueTwo = 2; // with return value var sum = WithSomeContext(() => valueOne + valueTwo); WithSomeContext(() => Console.WriteLine("Hi-There")); } }

That’s just boilerplate which I really don’t need. In many other languages, for example Scala, this is handled more elegantly. The void-type (often called Unit) is a regular type. And void/unit values just represent ‘void/unit‘:

class Example{ def withContext[T](runInContext:()=>T):T ={ // do magic and stuff val result = runInContext(); // do other stuff return result; } // no need for another method. // Our withContext also can accept 'void'-returns aka Unit def useIt() { val valueOne = 1; val valueTwo = 2; var sum = withContext(() => valueOne + valueTwo); withContext(() => println("Hi-There")); } }

Yes, I know, it’s not the end of the (programming) world. There are tons of other issues which lead to more boiler-plate. Anyhow, it is such a little thing and still so god damn annoying. God help us that no new programming includes the same little weakness =).

Tagged on: C#, java, Scala

Gamlor

thoughts about programming, tv-series and other geeky stuff.

Annoying Void in C# / Java / alike