Tayseer On Programming

Yeah, this is because the creation of the actual generic types in runtime and distinction between generics and inheritance. Still odd though!

But hey, instead of the stupid foreach code, .NET 3.5 can make this less painful :)

I think what you are trying to achieve is something like:
return (IList<IIdentity>)identityList;

This in .NET 3.5 can be done in this line:
return new List<IIdentity>( identityList.Cast<IIdentity>() );

The Cast<T>() method is an extension method to IEnumerable that exists in System.Linq namespace, you need to import that as well:
using System.Linq;
But it's in the "Class" Visual Studio "New Item" template anyway, so, you are only writing the actual line.


Calling Cast<IIdentity>() returns an IEnumerable<IIdentity> that you can use to fill in a new List<IIdentity>.
And of course List<IIdentity> inherits IList<IIdentity>, the following code is fine and would normally compile:
IList<IIdentity> iIdentityList = new List<IIdentity>( identityList.Cast<IIdentity>() );

But as the last line has the same variable name stupidity issue, the good news is you DO NOT NEED TO WRITE IT :).
It's implicit cast in this new case, so the return statement above would just work with no additional work.

Of course I realize that you should have not even had to cast, as it should have been implicit conversion as well, ideal code would be just returning an List<Identity> from a method with return type IList<IIdentity> with zero additional code, like just:
return identityList;  // where that object is List<Identity>

However, as the generic type gets created in the runtime, the generic part is not used fr inheritance chain. That's why you have to call for someone to do the cast as the line I showed earlier:
return new List<IIdentity>( identityList.Cast<IIdentity>() );