Is Predicate available anywhere in .NET? From MSDN http://msdn.microsoft.com/en-us/library/bfcke1bz.aspx, I don't see a Predicate anywhere. I see an anonymous that returns a boolean but no generics or a "Predicate" keyword. ...
Hi, I am trying to serialize something based upon meeting particular criteria. To this end my original hope was to use attributes containing a lambda expression on an object's properties. However, as this cannot be done I've settled for having a Func<T,bool> member within the class and passing the type (or first parameter type) and na...
I know it isn't possible to inherit from a generic type parameter, but it would be handy when implementing a common proxy for derivatives of an abstract type :-) Does anyone know why this isn't possible? Example C#: abstract class Foo { public virtual void Bar() { // nop } } class FooProxy<TFoo> : TFoo where TFoo : Foo {...
Dear ladies and sirs. Imagine the following perfectly legal type hierarchy: class A<T> where T : A<T> { } class B : A<B> { public B():base(){} } My question is given a statically compiled definition of A<> is it possible to emit the type B dynamically? The problem is how to specify the parent type in ModuleBuilder.DefineType. Or...
I have the following code private Map<KEY, Object> values = new HashMap<KEY, Object>(); public void set(KEY key, Object value) { values.put(key, value); } private Object getObj(KEY key) { return values.get(key) == null ? key.getDefaultValue() : values.get(key); } public List<E> getList(KEY key) { return (List<E>) getObj(key); } ...
I'm solving algorithmical problems, and i want to write custom functions and predicates that can be applied to collections. Recently, i started using Google Collections and it is just wonderful for this task. I want to use BigInteger and BigDecimal same way, as i would use any other numbers. Without pondering how it should be done, i d...
i'm implementing a generic interface (iqueryprovider, specifically). at some point, i'm forced to return a generic result, that i need to get from some internal interface: public TResult Execute<TResult>(...) { return something.Foo<TResult>(); } where something.Foo is public T Foo<T>() where T: MyBaseClass, new() { ... } this o...
I have an enum type like this as an example: public Enum MyEnum { enum1, enum2, enum3 }; I'll read a string from config file. What I need it to parse the string to MyEnum type or null o not defined. Not sure if the following codes will work (sorry for not having access to my VS right now): // example: ParseEnum<MyEnum>("ENUM1", r...
I have a persistence framework, and I am trying to use generics so I don't have to keep creating new list classes for each type of object I want to store in a type safe way. I have a method that returns the class of the contained object in the list class (so I know which queries to run and which object to create. As an example, it look...
Hello, I have an strongly typed DataTable 'MyType', I'd like convert it in an List. How can I do this ? Thanks, ...
I could be wrong but I'm guessing from this previous SO post that, since an enum in Java cannot be declared locally, that therefore it is therefore problematic for a method to return type Enum? I can declare that a method should return an Enum (see below) but how would one then go about implementing such a method to return anything othe...
I have a view ViewUserControl<SearchViewData> where SearchViewData: CommonViewData In this view I thus have a reference to Html. This is of the type HtmlHelper<SearchViewData> I create a custom HtmlHelper class called CommonHtmlHelper where I want to this (note the HtmlHelper parameter's type): public static SelectList Translat...
I'm trying to build a factory method that uses the generics feature of C#. In this factory method I would like to constraint it to some specific classes, all of which do not have a default constructor. Here is my example. Can someone tell me if it's possible to run it? public class AbstractClass { //this abstract class does not h...
I've run into an issue in Java's Generics in which the same code will compile and work fine in Java 6, but will fail to compile because of the same erasure in Java 5. I have a file TestErasure.java that has an overloaded method, called "method": import java.util.ArrayList; import java.util.List; public class TestErasure { public stati...
IQueryable<T> IS3Repository.FindAllBuckets<T>() { IQueryable<object> list = _repository.GetAllBuckets().Cast<object>().AsQueryable(); return list == null ? default(T) : (T)list; } This is the error: Error 3 Cannot implicitly convert type 'T' to 'System.Linq.IQueryable'. An explicit conversion exists (are you missing a cast?) I ...
When serializing a custom generic collection to Xml how do I add an attribute to the generated collection element. Currently I have: <RootObject> <Id>1</Id> <Items> <MyCollectionItem/> <MyCollectionItem/> </Items> </RootObject> What I need is: <RootObject> <Id>1</Id> <Items Name="My collection name"> <MyCollec...
Anybody knows how to write the piece of code below using generics AND avoiding compiler warnings ? (@SuppressWarnings("unchecked") is considered cheating). And, maybe, checking via generics that the type of "left" is the same as the type of "right" ? public void assertLessOrEqual(Comparable left, Comparable right) { if (left == nul...
I have been playing with generics and was hoping I could get some feedback or suggestions on a function I created to help handle reading null values from the DB. My main concern is in the if statement. Is there a better way to find out if T is a string ect.? Thanks. public static T CheckNull<T>(object value) { if ((value ...
Context I want to make this call via reflection instanceOfEventPublisher.Publish<T>(T eventInst); When I call ` private void GenCall(IEventPublisher eventPublisher, object theEventObj){ var thePublisher = eventPublisher.GetType(); thePublisher.InvokeMember( "Publish", BindingFlags.Default | B...
i'm creating an html.helper for a 3rd party javascript grid component. i'm passing my gridextension my viewmodel. in my viewmodel class i've got custom attributes on my properties describing how each column is displayed. in my gridextension, i want to then serialize my class of T. in my CreateSerializedRow method i'd like to be a...