Alex Rivera | Logout

Using a 'using alias = class' with generic types?

Asked 2011-02-08T18:38:47.213
139

So sometimes I want to include only one class from a namespace rather than a whole namespace, like the example here I create a alias to that class with the using statement:

using System;
using System.Text;
using Array = System.Collections.ArrayList;

I often do this with generics so that I don't have to repeat the arguments:

using LookupDictionary = System.Collections.Generic.Dictionary<string, int>;

Now I want to accomplish the same with a generic type, while preserving it as a generic type:

using List<T> = System.Collections.Generic.List<T>;

But that doesn't compile, so is there any way to achieve creating this alias while leaving the type as generic?

c# .net generics alias
Edit
Report

1 Answer

17

as shown at http://msdn.microsoft.com/en-us/library/sf0df423.aspx and http://msdn.microsoft.com/en-us/library/c3ay4x3d%28VS.80%29.aspx, you can do

using gen = System.Collections.Generic;
using GenList = System.Collections.Generic.List<int>;

and then use

gen::List<int> x = new gen::List<int>;

or

GenList x = new GenList();

however you have to replicate those using definitions at every file where you use them, so if you make some changes to them in the future and forget to update at every file, things will break badly.

I hope C# in the future Will treat aliases like the do with extension methods and let you define many of them in a file that you use elsewhere, then maintain them at one place and hide the internal unnecessary type mapping details from the type consumers.

answered 2012-07-04T19:12:05.677

Your Answer