I don't even think I have the question correct as I am just starting with generics and my knowledge isn't very great. Say I have the following method: public class Wrapper { public List<TInfoType> GetInfo<TInfoType>(Array data, EdmCmd edmCmd) { switch (edmCmd.meCmdType) { case EdmCmdType.EdmCmd_PostAdd: ...
A co-worker of mine asked me last week if it were possible in C# to extend a generic class from its generic parameter. He said it was possible in C++. What he wanted makes actually sense. He wanted a generic decorator to annotate an arbitrary class with additional information. Something like: pubic class Decorator<T> : T { public obj...
Hi folks, been struggling with this for a couple of days now and still stumped. i have a data structure that starts with containers that can hold other containers, and eventually leaf nodes. i'm looking for a way of being to iterate thru elements of a type directly, without pulling them into another collection so i can operate on them i...
Can I contain two different types in a collection? For example, can I have List< String U Integer > ? ...
I'm looking for best practices here. Sorry. I know it's subjective, but there are a lot of smart people here, so there ought to be some "very good" ways of doing this. I have a custom object called Employee. That object has seven properties like name, phone, email, and so on. There is also a table in my SQL database called tblEmployees...
or the other way around? I use generic lists all the time. But I hear occasionally about IEnumerables, too, and I honestly have no clue (today) what they are for and why I should use them. So, at the risk of having something on the net forever more proclaiming my ignorance, I humbly post this question. ...
Given the following models adapted from http://www.djangoproject.com/documentation/models/generic%5Frelations/ class TaggedItem(models.Model): """A tag on an item.""" tag = models.SlugField() content_type = models.ForeignKey(ContentType) object_id = models.PositiveIntegerField() content_object = generic.GenericForeig...
Possible Duplicate: IList<Type> to IList<BaseType> I am programming in C# using .NET 2.0 and I don't understand why the cast below results in a null reference. If you have an IList<IChild>, why can't you cast it to an IList<IParent> where IChild implements IParent. using System.Collections.Generic; namespace InterfaceTest { ...
I am trying to do the following: Given TypeInfo after reflecting on a LINQ-to-SQL object with various EntitySet<> child collections, retrieve the collection Do some operations on the collection The code below does not compile, obviously - just looking for another way to do this [Note, "Facade" is the L2S object in question). The thi...
When we declare (example) List<T> I can understand the declaration, but suppose I declare IEnumerable<T<T1, T2>> What did I actually declare? Does it mean, IEnumerable<T> contains two generic types? (What is the way to use it?) Can I have deep nested level like Person<T<T2<T3<P1,P2>>>>? Simple example will really helpful. ...
Basically, I want a class to be able to implement two different versions of the same generic interface. Consider this code type // a generic interface ITest<T> = interface ['{6901FE04-8FCC-4181-9E92-85B73264B5DA}'] function Val: T; end; // a class that purports to implement two different types of that interface TTe...
1)When I have Static void Sample<T>(T a,T b) Does the declaration Sample enforce that all parameters need to be of type T ? 2) Does the declaration Static void Sample(T a,T b) not a Generic method unless i specify Sample<T>? ...
Following on from another question I asked, I wanted to understand a bit more about the Scala method TraversableLike[A].map whose signature is as follows: def map[B, That](f: A => B)(implicit bf: CanBuildFrom[Repr, B, That]): That Notice a few things about this method: it takes a function turning each A in the traversable into a B i...
public class StuffDoer<T> { // do stuff } I want that this is always of type string, so instead of doing this: StuffDoer<string> stuffer = new StuffDoer<string>(); I want to be able to do this: StuffDoer stuffer = new StuffDoer(); and if I need a StuffDoer of type int, just define that with generics. StuffDoer<int> stuffer =...
I'm missing a trick here I think and can't believe I've never done this before. However, how can I cast a generic type using the as keyword? [Serializable] public abstract class SessionManager<T> where T : ISessionManager { protected SessionManager() { } public static T GetInstance(HttpSessionState session) { // E...
Is it possible to constrain the type of generic to, say, two different classes? Like so: TSomeClass<T: FirstClass; T: SecondClass> = class // ... end; (Sorry about the lack of formatting - the SO tool bar has disappeared from my browser). I know the above won't compile, its only written so to give you guys an idea. I tried TSomeCl...
In this code: TTest<IntfT: IInterface> = class protected fObj : TInterfacedObject; public function GetVal: IntfT; end; How would I implement the GetVal function if I want it to return fObj as an IntfT? I've tried: result := fObj as IntfT; and fObj.QueryInterface(IntfT,result); and result := fObj as IInterface; but noth...
I'm looking to create a set of functions which all implementations of a certain Interface can be extended to use. My question is whether there's a way to do this without using a proxy or manually extending each implementation of the interface? My initial idea was to see if it was possible to use generics; using a parameterized type as t...
I have some code that works like the below. I was wondering if its possible to get a Type object for the generic type passed to the DoSomething function. I realise that T is a type parameter but how would i turn this into a type object. The dosomething function is in a class where I want to know the underlying type used by the list ob...
When i need to pass a Generic Type I can use the Syntax (Example : Ofcourse it is not a Generic Method) public void Sample(T someValue) { ...... } What is the benefit of declaring Sample<T> ? I mean public void Sample<T> (T someValue) { ...... } ...