generics

问题 I've done some digging on similar questions but I cannot find a solution that works. I've got some types of generic functions, but I cannot seem to implement them correctly. In short, I have this: /** Takes three values of the same type and collapses them into one */ declare type MergeFunction = <T>(def: T, file?: T, arg?: T) => T /** The implementation I'm having trouble with. Merge three arrays of the same type. */ const arrayMerge: MergeFunction = <T>(def: T[], file: T[] = [], arg: T[] = [

问题 Awkward title I know, this is best explained in code. Given a set of classes: public abstract class MyBaseType { public string Message { get; set; } } public class MySuperType : MyBaseType { public string AdditionalInfo { get; set; } } public class MyOtherSuperType : MyBaseType { public DateTime Started { get; set; } public DateTime Finished { get; set; } } Is there a way to write a generic method that calls a non-generic method passing the generic type whilst interpreting the passed type as

问题 Assuming I have only the class name of a generic as a string in the form of "MyCustomGenericCollection(of MyCustomObjectClass)" and don't know the assembly it comes from, what is the easiest way to create an instance of that object? If it helps, I know that the class implements IMyCustomInterface and is from an assembly loaded into the current AppDomain. Markus Olsson gave an excellent example here, but I don't see how to apply it to generics. 回答1: Once you parse it up, use Type.GetType

问题 Assuming I have only the class name of a generic as a string in the form of "MyCustomGenericCollection(of MyCustomObjectClass)" and don't know the assembly it comes from, what is the easiest way to create an instance of that object? If it helps, I know that the class implements IMyCustomInterface and is from an assembly loaded into the current AppDomain. Markus Olsson gave an excellent example here, but I don't see how to apply it to generics. 回答1: Once you parse it up, use Type.GetType

问题 This question already has answers here : Is it impossible to use Generics dynamically? [duplicate] (2 answers) Closed 6 years ago . I'm trying to simplify my methods in creating several variables in a function which is repeated for different types and different actions, eventually I will migrate to a single function that can handle multiple types but I'm doing it in stages. I would like to be able to make a list of objects in their types instead of List without having to copy/paste the object

问题 Following are two methods in a class class Developer and Student are different and not share any parent. Both following method has same code and method called on both object have same name ex. getStartDate. class hierarchyValidator { private LocalDate[][] getArrayOfTimespan(List<Developer> developers) { //here i have to call some method on developer from list LocalDate startDate = developer.getStartDate(); .... } private LocalDate[][] getArrayOfTimespan(List<Student> students) { //here i have

问题 I am using C#/.NET 4.0 and a Protocol Buffers library (protobuf-net) which provides the following functionality. public static class Serializer { public static void Serialize<T>(Stream destination, T instance); public static void Serialize<T>(SerializationInfo info, T instance); public static void Serialize<T>(XmlWriter writer, T instance); public static void Serialize<T>(SerializationInfo info, StreamingContext context, T instance); public static T Deserialize<T>(Stream source); } I need to

问题 I want to add a custom serializer and deserializer for JSR 363 javax.measure.Quantity<Q extends Quantity<Q>> , which basically encapsulates a "value" and a "unit". Creating the serializer ( extends JsonSerializer<Quantity<?>> ) and the deserializer ( extends StdDeserializer<Quantity<?>> ) is easy. But it's not easy to register them. For deserializers, it's OK; look at the signature: SimpleModule.addDeserializer(Class<T> type, JsonDeserializer<? extends T> deser) Notice that the deserializer

问题 public static void main(String[] args) { Map<String, Map<Long, List<String>>> map = getHashMap(); } static <K,V> Map<K,V> getHashMap() { return new HashMap<K, V>(); } I saw a similar code in google guava (as factory methods) for making instances of Hashmap without mentioning the generic types.I don't understand how the generic is getting inferred by the above program.I mean how can the function getHashMap understand the type of map since i'm not passing any type information to the function.

问题 Ok question title is far from being self-explanatory. I see myself doing this often: From this answer: public static class Equality<T> { public static IEqualityComparer<T> CreateComparer<K>(Func<T, K> keySelector) { return new KeyEqualityComparer<K>(keySelector); } class KeyEqualityComparer<K> : IEqualityComparer<T> { readonly Func<T, K> keySelector; public KeyEqualityComparer(Func<T, K> keySelector) { this.keySelector = keySelector; } public bool Equals(T x, T y) { ---- } public int