This is kind of a follow to my other post about Unity (http://stackoverflow.com/questions/3998559/irepository-iservice-unity-in-an-asp-net-mvc-application-reference-question). Basically I'm trying to register a generic type in the web.config. I've read a few posts and this SEEMS like it is configured correctly. <unity xmlns="http://s...
Hello, I need to custom marshal/unmarchal a TDictionary in Delphi (XE). The dictionary is declared as: TMyRecord = record key11: integer; key12: string; ... end; TMyDict: TDictionary<string, TMyRecord>; Now, if i marshal the dictionary without registering a custom converter, the marshaller will put all kind of fields in the JSO...
Why can I only upcast a generic and not downcast it? How is it not clear to the compiler that if my constraint says where T : BaseClass and U is derived from BaseClass that (U)objectOfTypeT is valid? ...
Given a data type data Foo = Foo1 { foo1Name :: String} | Foo2 { foo2Name :: String, foo2Age :: Integer } I would like to be able to extract the Data.Data.DataTypeS of Foo1 and Foo2s fields. I tried datatype = (undefined :: Foo) constrs = dataTypeConstrs datatype foo1 = fromConstrs (head constrs) :: Foo foo1Fields = gmapQ dataT...
Hello, I have class like following: public class Tree<T extends Comparable<? super T>> { // private data omitted private Tree() {} // non parametric private constructor, not exposed // static factory method public static <T extends Comparable<? super T>> Tree<T> newInstance() { return new Tree<T>(); } } Now from anothe...
In such a function: <T> void foo(T obj) The type of obj.getClass() is Class<?> and not Class<? extends T>. Why? The following code works fine: String foo = ""; Class<? extends String> fooClass = foo.getClass(); So the signature of T#getClass() seems to return a Class<? extends T>, right? Why is the signature different if T really...
Here, I wondered about how to implement Collection#toArray(T[] array) properly. I was mostly annoyed that array.getClass().getComponentType() is of type Class<?> and not Class<? extends T> as I would have expected. Therefore, I coded these three functions: @SuppressWarnings("unchecked") static <T> Class<? extends T> classOf(T obj) { ...
I can't seem to figure this out...a little help please, thank you vm! I have a generic collection of Features. Each Feature has a FeatureId and FeatureName. I need to pass the featureids into an IEnumerable<string>. I thought I was close with this: Listing.Features.ToArray().Cast<string>().AsEnumerable(); and even tried to 'MacGy...
In the chapter Generics CLR Via C# v3, Jeffrey Richter says below TypeList<T> has two advantages Compile-time type safety boxing value types over List<Object>, but how is the Compile-time type safety is achieved? //A single instance of TypeList could hold different types. using System; using System.Collections.Generic; using System....
public K[] toArray() { K[] result = (K[])new Object[this.size()]; int index = 0; for(K k : this) result[index++] = k; return result; } This code does not seem to work, it will through out an exception: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to ... Could someone tell me how I can ...
I am using Entity Framework v4. I am trying to implement some logic to Validate my entities before they are saved by overriding the SaveChanges method. I am also POCO for my entities. I get a list of modified and new entities by doing the following. var entities = (ObjectStateManager.GetObjectStateEntries(EntityState.Added | EntityStat...
I am trying to get around a compile error ("Bound mismatch: ...") relating to dynamic enum lookup. Basically I want to achieve something like this: String enumName = whatever.getEnumName(); Class<? extends Enum<?>> enumClass = whatever.getEnumClass(); Enum<?> enumValue = Enum.valueOf(enumClass, enumName); Whatever I do, I always end ...
Hello, my question is about type variables used in generic classes and methods, why can't we do something like this T = new T(); "Construct an object of the type variable" i know that generic information is erased during compilation, and everything is converted to Object, so why doesn't the compiler assume that T is an object and let us ...
I have generic structure and I need to search using various generic type's attributes. Let's think of following implementation: public class Person { private int id; private String name; // + getters & setters } Now I have my custom data structure and one of it's method is like: public T search(T data) { ... } That is nonsen...
Here is an example of some code I'm working on: public interface FooMaker<T extends Enum<T> & FooType> { public List<Foo<T>> getFoos(String bar); } Let's further assume there will be many different concrete implementations of FooMaker. So I wrote some code to utilize the FooMakers. FooMaker<?> maker = Foos.getRandomMaker(); Li...
I'm refactoring some code that was originally designed with generics to also work with reflection. The particular code base has default(T) scattered throughout. I've created a method that will look similar named Default(T), but I don't think my implementation is correct. Essentially my implementation looks like this: private object D...
specificly im trying to write a piece of code that will allow me to perform basic math operations on a "T extends Number" object variable. it needs to be able to handle any number type that is a subclass of Number. i know some of the types under Number have .add() methods built in, and some even have .multiply() methods built in. i need ...
Firstly, I've asked this question elsewhere, but meta.stackoverflow.com seems to think that asking the same questions elsewhere is fine, so here goes. I'll update both if/when I get an answer. I'm doing a lot of conversion between simple types and I wanted to handle it as nicely as possible. What I thought would be nice would be to be a...
hello, I am writing a wrapper for a class written in C++. I must have an template interface class and inherif a wrapper class for a certain type of variable. this is the code template<typename T> public interface class IDataSeriesW { property T default [int] { T get (int Index); void set (int Index ,T val); } }; publi...
I have one generic interface in c#, and almost always I use it with one of the types. I want to create a non-generic interface for that type and use it. Let's say, I've the following code: public interface IMyGenericList<out T> where T : IItem { IEnumerable<T> GetList(); } public class MyList<T> : IMyGenericList<T> where T : IItem...