I profiled my code and found out that my class, which implements Comparable<T>, spends 8x more cpu time in compareTo(Object) than in compareTo(T) I assume that the slowdown is because of virtual table lookup for this method. Is there a way to force static invocation of the function? (like in non virtual C++ methods) I still wa...
Suppose I have two C++ classes: class A { public: A() { fn(); } virtual void fn() { _n = 1; } int getn() { return _n; } protected: int _n; }; class B : public A { public: B() : A() {} virtual void fn() { _n = 2; } }; If I write the following code: main() { B b; int n = b.getn(); } One might expect that n is set ...
I have an abstract class in a library. I'm trying to make it as easy as possible to properly implement a derivation of this class. The trouble is that I need to initialize the object in a three-step process: grab a file, do a few intermediate steps, and then work with the file. The first and last step are particular to the derived class....
If I have one base class and I derive 10 different concrete derived classes from it then will each and every concrete derived class have a different vtable? ...
I've been having a discussion with my coworkers as to whether to prefix overridden methods with the virtual keyword, or only at the originating base class. I tend to prefix all virtual methods (that is, methods involving a vtable lookup) with the virtual keyword. My rationale is threefold: Given that C++ lacks an override keyword, the...
hi guys, i have the following classes: class A { protected: A *inner; public: .... virtual void doSomething() = 0; .... } class B: public A { ... void doSomething() { if(inner != NULL) inner->doSomething(); } ... } When I use inner->doSomething() I get a segmentation fault. What should I...
Ola the 'flow! I have been using Moq recently in my development process and I like what I am able to achieve. However, I find myself making my methods (and properties for the mostpart) virtual so that I can replace them with a mock in my tests. Other than "you are making all your methods and properties overrideable", what real world r...
First let's establish this. I have public abstract class Foo { public static void StaticMethod() { } } public class Bar : Foo { } is it valid to call Bar.StaticMethod(); ??? If so, let's expand previous example: public abstract class Foo { public static void StaticMethod() { } public abstract void VirtualMethod(); ...
I have a class which doesn't currently need to be thread-safe, but in future we might want to make a thread-safe version. The way I see it, I can either make it thread-safe now by putting locks around the relevant functions, or I can make them virtual now and put locks around them in overrides in a descendent class later on. That is, t...
This is an extension for this question asked an hour ago. We cannot modify the access modifiers, when overriding a virtual method in derived class. Consider Control class in System.Web.UI namespace public class Control : IComponent, IDisposable,... { protected internal virtual void CreateChildControls() { } . . } Now Con...
Consider this simple Java class: class MyClass { public void bar(MyClass c) { c.foo(); } } I want to discuss what happens on the line c.foo(). Original, Misleading Question Note: Not all of this actually happens with each individual invokevirtual opcode. Hint: If you want to understand Java method invocation, don't read just...
Hi, There is a thing I do not understand well: when virtual method is called, the base method is called as well? Because when I use public override WinForm OnPaint method, in its body base.OnPaint(e) is called. I do not understand it, I thought virtual methods overrides the original one. If it is not usually called, why it is called in ...
I can't do this interface InterfaceA { void MethodA(); } class ClassA : InterfaceA { virtual void InterfaceA.MethodA() // Error: The modifier 'virtual' is not valid for this item { } } Where the following works class ClassA : InterfaceA { public virtual void MethodA() { } } Why? How to circumvent th...
I have a class designed to do import/export of data in one of a few different formats. Each format should have exactly the same interface, so I'm implementing it as a base class with a bunch of virtual methods and a derived class for each specific format: #ifndef _IMPORTEXPORT_H_ #define _IMPORTEXPORT_H_ #include "stdio.h" enum EXPORT...
I create a parent class that calls it's own virtual member. But this virtual member is overridden by child class. class Parent { public: void doSomething() { doVirtual(); } protected: virtual void doVirtual() {} }; class Child : public Parent { protected: virtual void doVirtual() {} }; Parent *c = new Child(); ...
I have a set of classes, where each class represents a diferent type of a database field. For example, a very basic subset of it would be: public abstract class DbObject { internal DbObject() { } } public class DbInteger : DbObject { public int Data { get; set; } public DbInteger(int data) { this.Data = data; } } public class ...
Just starting to use Java. I find a lot of similarities with .NET, but I see that all methods in Java are virtual by default. So the question is what can I do to make them non virtual ? Is the final keyword the one and right solution ? ...
Consider the following code (it's a little long, but hopefully you can follow): class A { } class B : A { } class C { public virtual void Foo(B b) { Console.WriteLine("base.Foo(B)"); } } class D: C { public override void Foo(B b) { Console.WriteLine("Foo(B)"); } public void Foo(A a) { ...
I want to know if i don't put override key word before the method in derived class method m1(), then what is the default value before this, or will it throw a compile time error? class A { virtual void m1(){} } class B: A { void m1(){} } ...