What features do you wish were part of C#?

Question

... and things that you still look forward to seeing in the upcoming versions.

Answer 1

This topic has essentially been covered here. It contains some very interesting suggestions indeed (a few of which are in fact noted to be planned for C# 4.0). Definitely worth reading through the whole thing.

Answer 2

Property-scoped fields

public int N {
  private int n, m = 3;
  get { return n + m; }
  set { n = value; }
}

Chained null checks

if (document!RootNode!ChildNode != null) ...

Answer 3

Multiple setters:

private Uri _linkUrl;
public Uri linkUrl
{
    get { return _linkUrl; }
    set
    {
        _linkUrl = value;
    }
    set<string>
    {
       _linkUrl = new Uri(value);
    }
}

//this of course works fine
MyObj.linkUrl = new Uri("http://stackoverflow.com"); 

// but I could also just do this:
MyObj.linkUrl = "http://stackoverflow.com";

Answer 4

Conditional/filtered event handlers:

class A
{
   public event EventHandler MyEvent;
}

class B
{
   int x;
   A classA = new A();
   public ClassB()
   {
     classA.MyEvent += new EventHandler(OnMyEvent).Where(x > 5);
   }
}

This would mean I only get events when the filter is matched. I could also envisage using other LINQ-style operators such as First() where you only get the event fired once and then never again.

For example, instead of writing:

   private void OnMyEvent(object sender, EventArgs e)
   {
      if (x > 5)
      {
         // Do stuff.
      }
   }

I can specify the condition where the handler is attached to the event. The compiler would insert a new handler behind the scenes with the condition applied based on the method I define. This way, i can define a single handler that is used with different conditions on multiple events rather than needing one handler per event just because I need a different condition or filter in there. There wouldn't be a need for any new CLR support - this would just be syntax changes.

I want language support for exception filters as well.

Update

I believe my "filtered events" concept can be created through the use of .NET 4 and the Rx framework.

Answer 5

Nullable strings

string? strx; 
strx.GetValueOrDefault(string.Empty);

Extension Properties

Same as extension methods but properties, would allow extending unowned code into fluent interfaces

objX.Is().Not.Something();

vs

objX.Is.Not.Something();

Answer 6

• Static extension methods and properties
• Built-in arithmetic support in Generics

Answer 7

"Friend" keyword from C++. It opens great possibilities in right hands.