Recent questions tagged Generics

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generics - Is there a way to say "method returns this" in Java?

Is there a way to say "this method returns this" using Generics? Of course, I want to override this method in ... a cast, the override fails. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - What is the meaning of the <?> token in Java?

What is the meaning of the <?> token in this code copied from www.JavaPractices.com? When I replace it ... it still compiles and runs properly. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Relating parameterized types

I have a map where both the keys and values are generic types. Something like this: Map[Foo[A], Bar[A]] What ... , the compiler can't know this. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - F# compilation error: Unexpected type application

In F#, given the following class: type Foo() = member this.Bar<'t> (arg0:string) = ignore() Why ... the error: "Unexpected type application" See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - F# member constraints + ^a byref parameters

After some playing around F# member constraints feature and writing function like this: let inline parse< ^a when ^a ... What am I doing wrong? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - In Java is it possible to create a type-safe Map of classes to instances of their class?

I would like to create a map that uses a class as a key to return an instance of that class. Something ... that answer and not posted this. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Java bounded wildcard in return type

I've read in various places including here that having a bounded wildcard in a method return type is a bad idea. ... Is there a way round this? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - In Java is it possible to create a type-safe Map of classes to instances of their class?

I would like to create a map that uses a class as a key to return an instance of that class. Something ... that answer and not posted this. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Java bounded wildcard in return type

I've read in various places including here that having a bounded wildcard in a method return type is a bad idea. ... Is there a way round this? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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549 views

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generics - Why does Java's TreeSet<E> remove(Object) not take an E

From the Java 6 TreeSet<E> Documentation: boolean remove(Object o): Removes the specified element from this set if it ... should be of type E. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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527 views

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generics - Find type parameter of method return type in Java 6 annotation processor

I'm writing a tool that uses the annotation processor to generate source code depending on the return type of ... the whole java type system? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Scala fails to infer the right type arguments

Background info: I'm currently trying to set up a generic graph library that includes a few different search ... graph, Position(0,0)) See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - How to do `MyClass<String>.class` in Java?

How can call public <T> T doit(Class<T> clazz); using MyClass<String>.class as clazz where I can not ... the condition to my original question. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Complete, efficient NumericLiteral module implementation

Building on a discussion in this question, could anyone provide code, or a link to code, showing a complete ... this be improved and completed? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Complete, efficient NumericLiteral module implementation

Building on a discussion in this question, could anyone provide code, or a link to code, showing a complete ... this be improved and completed? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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538 views

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generics - How is Progress<T> different from Action<T> ? (C#)

I've been using Progress<T> and wondered if it can be replaced by Action<T>. In the code below, using ... How is Progress different from Action? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Golang: cast an interface to a typed variable dynamically

In go, is it possible to cast variables dynamically somehow? For example, if a simple cast would be: var intAge ... would work for all types). See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Why is anonymous class required in "super type token" pattern in java

In Neal Gafter's "super type token" pattern (http://gafter.blogspot.com/2006/12/super-type-tokens.html), an ... T> actual parameterized type : T See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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606 views

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generics - C# delegate for two methods with different parameters

I am using the following methods: public void M1(Int32 a) { // acquire MyMutex DoSomething(a); // release ... documentation? Environment: C# 2.0 See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Lazy class cast in Java?

Can someone please enlighten me as to why I don't get a ClassCastException in this snippet? I'm strictly interested ... Test.main(Test.java:30) See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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644 views

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generics - What is the <T> in Cast<T>() or List<T> in C#

I know this is probably a dupe, but I can't for the life of me remember what the name is or even how ... benefit do they provide? Generics, FTW See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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697 views

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generics - Java ArrayList of ? extends Interface

I have a group of classes that all implement a validation interface which has the method isValid(). I ... for both interfaces and subclasses. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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651 views

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generics - Scala: "Parameter type in structural refinement may not refer to an abstract type defined outside that refinement"

I'm having a problem with scala generics. While the first function I defined here seems to be perfectly ok, ... scala 2.8RC1 Regards, raichoo See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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548 views

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generics - How to write a trait bound for a reference to an associated type on the trait itself?

I have this code: extern crate serde; use serde::de::DeserializeOwned; use serde::Serialize; trait Bar<'a, T: ... ::to_string(&t).unwrap() } See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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generics - Polymorphic Scala return type

I have an abstract Scala class Base which has subclasses Derived1 and Derived2. Base defines a function f() ... as Derived1 in this context. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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530 views

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generics - What is the Collections.checkedList() call for in java?

I just want to know for what java.util.Collections.checkedList() is actually used. I have some code that I ... each element is a String. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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497 views

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generics - C# Converting List<int> to List<double>

I have a List<int> and I want to convert it to a List<double>. Is there any way to do this ... take advantage of the new language features. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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587 views

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generics - C# Dictionary with two Values per Key?

I have a situation in code where a Dictionary<string, string> seemed like the best idea - I need a ... something simpler for this scenario? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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