member

问题 I tried like that: member e [] = False member e xs = foldr (==) e xs and then: member 3 [1,2,3,4,5] and I get this error message: No instance for (Num Bool) arising from the literal `3' In the first argument of `memb', namely `3' I don't know what it means... can someone help me? PS: member is a function that, given a element and a list of elements, returns whether the element belongs to that list or not. The usual implementation is: member a [] = False member a (x:xs) | (a == x) = True |

问题 I'm writing documentation for package I've published, and I find the more thorough your documentation, the easier people find your package to use (duh). I'm actually having a lot of fun lovingly writing up all the features and details of my code. However, I'm completely flummoxed by how to write Sphinx-compatible documentation for class-level variables. In particular, I've got some enum classes I'd like to document, but for the life of me I can't figure out a way to attach documentation to

问题 why or for what reason is it not possible to declare a class member variable in C++ as static mutable ? Something like static mutable int t; //This won't compile For me, there is no reason to ban such declarations. E.g. for reasons like maintaining a global class-wide statistics, it may be convenient to have static variable that can be altered by (logically) const methods. So either this is sort of a misdesign in C++ and unnecessarily complicated, or there is a practical or theoretical reason

问题 My problem is about passing a member function from a Class A, to a member function of a Class B: I tried something like this : typedef void (moteurGraphique::* f)(Sprite); f draw =&moteurGraphique::drawSprite; defaultScene.boucle(draw); moteurGraphique is A class, moteurGraphique::drawSprite is A member function, defaultScene is an instance of B class, and boucle is B member function. All that is called in a member function of A: void moteurGraphique::drawMyThings() I tried different ways to

问题 Inside a MVC controller I attempted to create a field similar to: Func<MyModel, ViewResult> ModelResult=(model) => View("myview.cshtml", model); This results in the compilation error An object reference is required for the non-static field, method, or property 'System.Web.Mvc.Controller.View(string, object)' This code works fine as a method private ViewResult ModelResult(MyModel model) { return View("myview.cshtml", model); } It also works fine if the field is initialized by the constructor

问题 I want to get the collection of all the members that are present in a class. How do I do that? I am using the following, but it is giving me many extra names along with the members. Type obj = objContactField.GetType(); MemberInfo[] objMember = obj.GetMembers(); String name = objMember[5].Name.ToString(); 回答1: Get a collection of all the properties of a class and their values: class Test { public string Name { get; set; } } Test instance = new Test(); Type type = typeof(Test); Dictionary

问题 I found recent interest in Kotlin as a language, because the platform we develop for is Java 6 based and hence lacks any syntactic sugar the recent years brought to Java. There's but one thing that makes it impossible to use Kotlin over Java in development, that is, the platform we develop for uses some reflection internally and requires members to be public. It won't work otherwise. So, the bytecode generated from the Kotlin file in fact produces public getters and setters, the fields

问题 I found recent interest in Kotlin as a language, because the platform we develop for is Java 6 based and hence lacks any syntactic sugar the recent years brought to Java. There's but one thing that makes it impossible to use Kotlin over Java in development, that is, the platform we develop for uses some reflection internally and requires members to be public. It won't work otherwise. So, the bytecode generated from the Kotlin file in fact produces public getters and setters, the fields

问题 What is the best or conventional method to align members inside a structure? Is adding dummy arrays the best solution? I have a struct of double and a triple of double s? struct particle{ double mass; std::tuple<double, double, double> position; } If I have an array of these, the memory will look like this [d][d d d][d][d d d][d][d d d]... The problem is that the distance from the first triple to the second triple is not an integer multiple of sizeof(std::tuple<double, double,double>)==3

问题 I'm currently having trouble with part of Chapter 6 of "Programming: Principles and Practice Using C++" (2nd ed, 3rd printing). According to the book's index, an example of a member initializer list is on page 184. Part of page 184 reads as follows: "Here, we'll just provide two member functions to give us a more convenient way of initializing Tokens: class Token { public: char kind; // what kind of token double value; // for numbers: a value }; We can now initialize ("construct") Token