Is there any way I can change this code so I can remove the unchecked warning ArrayList<String> keys = new ArrayList<String>(); // do some stuff then // save keys in session HttpServletRequest request = getThreadLocalRequest(); HttpSession session = request.getSession(true); session.setAttribute(uuid, keys); // get keys from session so...
Can anyone explain why the second example below won't compile? 'Test 2' gives "error FS0670: This code is not sufficiently generic. The type variable ^a could not be generalized because it would escape its scope.". I fail to understand this error message. // Test 1 type test1<'a> = | A of 'a with override t.ToString() = ...
Is it faster the List.Remove(T) or List.RemoveAt(int) method in .NET collections? Is speed different for value types or reference types? Thanks, Alberto ...
I have an interface as follows: public interface ISelectEntity { List<T> GetFromDB<T, O>(O data); } I'm implementing it as follows within a StatusCodes class List<StatusCodes> ISelectEntity.GetFromDB<StatusCodes, StatusCodesInputParameters>(StatusCodesInputParameters data) { return EntitiesClass.PopulateStatusCodes(E...
If I have a generic class: public class MyClass<T> { public T Value; } I want to instantiate several items such as... new MyClass<string> new MyClass<int> ...and add them to a collection. How do I define the collection so that it can hold a list of generic types? I then want to iterate through the collection at some point, and u...
I'm using VB.NET with .NET 2.0. I have two lists, and I want to compare the lists on a specific property in the object, not the object as a whole, and create a new list that contains objects that are in one list, but not the other. myList1.Add(New Customer(1,"John","Doe") myList1.Add(New Customer(2,"Jane","Doe") myList2.Add(New Cust...
Suppose I have a method to return a list of keys in a dictionary, sorted by their values: /// Perhaps a wildly inefficient way to achieve this! public static List<K> SortByValues<K,V>( Dictionary<K,V> items ) { var keys = new K[items.Count]; var values = new V[items.Count]; var index = 0; foreach( var kvp in items ) ...
Assigning values without using usual notation like "this.<Double>getAnything(int flag)" private <T> T getAnything(int flag) { Object o = null; if (flag==0) o=new String("NewString"); else if (flag==1) o=new Double(0D); return (T)o; } private void someMethod() { String s = getAnything(0); Double ...
class Program { static void Main(string[] args) { Type t = typeof(A<,>); Console.WriteLine(typeof(A<,>)); // prints A'2[T1,T2] } } class A<T1,T2> { } As far as I know, generic type A<T1, T2> is not an actual type, but rather a blueprint/template for an actual type, so why does typeof accept it as a par...
why in the first line of this code: template <typename VectorType> std::string repr_vector_dynamic(const VectorType* vect) { std::stringstream strs; strs << "("; for (int i = 0; i < vect->size(); ++i) { if (0 != i) { strs << ", "; } strs << (*vect)[i]; } strs << ")"; return str...
This post (http://blogs.msdn.com/b/brada/archive/2005/01/18/355755.aspx) says IEnumerable<T> is Contra-variant. However type T is co-variant because it is an out parameter. So in what context is IEnumerable<T> Contra-variant ?? Hope I am not confusing! Thanks for the answers in advance! ...
Hi, at the moment I'm using a List<short> as a buffer to hold things for a while while a calculation is made to each value based on other values further down the buffer. I then realised that this probably wasn't very effecient as I have been told that List<> is a linked list so every time I do whatever = myList[100]; the poor thing is ha...
Hi all, I have a generic method (in a non generic class) returning elements. public IEnumerable<T> GetElements<T>() where T : class { foreach (Element element in elements) { if (element is T) { yield return element as T; } } } I want to transform...
Hello, I am trying to mock a generic interface and whenever I mock it, I gets this warning The expression of type GenericInterface needs unchecked conversion to conform to GenericInterface My interface is interface GenericInterface<T>{ public T get(); } and My test is @Test public void testGenericMethod(){ Generic...
If i declare a generic class as something like public class Driver<V extends Car> where Car is an interface. Then, I use it with something like this: Driver<?> driver = new Driver<Chevrolet>(); I don't want to specify a specific implementation of car as the generic. Why is it that I cannot call methods implemented in driver that ...
I'm working on creating a new base class for an asp.net app in order to create my own version of a strongly typed view from MVC. The app itself is NOT a MVC app though. Below is the basis of my custom class. public class BasePage<T> : Page where T : IPageInfo { public BasePage() { this.MyPageInfo = IoC.GetInstance<IPag...
[WebMethod] public void Test(KeyValuePair<string,string> details) { } I have defined the above web-method. The KeyValuePair is defined in http://schemas.datacontract.org/2004/07/System.Collections.Generic how can i add it to my wsdl auto-generated file? i have to define this type because otherwise i get an empty definition...
I'd like to create a class of the following type public class EnumerableDisposer<IEnumerable<IDisposable>> But it won't let me declare it this way. I've also tried: public class EnumerableDisposer<T> : IDisposable where T : IEnumerable<J> where J : IDisposable But the compiler tells me that the type/namespace J could not be found....
I've got a method I'm trying to translate from c# to vb, goes something like this .. x.For(typeof(IRepository<>)).Use(typeof(Repository<>)); VB doesn't seem to like the idea of a IRepository(Of ) ... what's the syntax on that? ...
I'm writing a generic type to handle the underlying Active Directory objects such as groups, organisational units and users. I'm also using "manual" dependency injection within my generic interface. I would like to know if, in my situation, which is more appropriate: generic interface or generic method? Here's a simplified code sample ...