why do we need virtual methods in C++?

May 31, 2016 Calling a virtual method through an interface always was a lot slower than calling a static method through an interface. But why is that? Sure, the virtual method call costs some time, but comparing it with the difference of a normal sta

1.Instance Constructors and Classes (Reference Types) Constructors methods : 1.allow an instance of a type to be initialized to a good state. 2.are always called .ctor (for constructor) in a method definition metadata table. 3.When creating an instan

Lately I've received several questions along the lines of the following, which I typically summarize as "async over sync": In my library, I have a method "public T Foo();".  I'm considering exposing an asynchronous method that would si

前言 最近在复习一些 C++基础知识,写了一些 C++的代码,当我在类中定义了虚函数并且直接在类定义内部实现这些虚函数时,编译器就会报警告:’xxx‘ has no out-of-line virtual method definitions:its vtable will be emitted in every translation unit.如下图: 如何解决 以前好像从来没留意过这些问题,然后决定找找原因,后来查了一些资料终于找到真正的原因,来看一段话:If a class is def

原文: http://arne-mertz.de/2015/12/modern-c-features-override-and-final/ Today I write about a pair of less often discussed, less complicated features introduced in C++11, which are nevertheless useful. Both can provide some additional security and cla

From: http://www.codeproject.com/Tips/441838/Designing-the-Interface-of-DLLs-in-C-Cplusplus-P Introduction This tip assumes that you are familiar with DLL usage and related terms like static/dynamic linking. If you have no idea how to use DLLs, then

1.which of the following is not automatically generated by the compiler? a. default constructor    b. copy constructor    c. equality operator(op==)     d. assignment operator(op=)       e. destructor 2.which of the following is not an STL collection

原文: http://www.codeguru.com/cpp/cpp/cpp_mfc/callbacks/article.php/c10557/Callback-Functions-Tutorial.htm Callback Functions Tutorial Introduction If you are reading this article, you probably wonder what callback functions are. This article explains

试题网址: http://www.shiyanbar.com/ctf/1871 0x01 首先我们得到了一个hello.dex文件,要把它反编译为smali文件,使用工具baksmali,cmd命令:  java -jar baksmali-2.0.3.jar -o class/ Hello.dex ,就在当前目录下生成了一个文件夹,里边有一个hello.smali 代码如下: .class public LHello; .super Ljava/lang/Object; .source "He