virtual

Can a compiler inline a virtual function if I use a pointer in a clear situation?

由 倾然丶 夕夏残阳落幕 提交于 2019-12-06 22:10:03
问题 I've already read Are inline virtual functions really a non-sense?. But I still have some doubts and found no answer there. They say that if situation isn't ambiguous, compiler should inline the virtual function . However: This can happen only when the compiler has an actual object rather than a pointer or reference to an object. So what if I have a B class derived from an A one (which contains a virtual void doSth() function) and I use the B* pointer, not the A* : B* b = new B; b->doSth();

UVM中的class

由 痞子三分冷 提交于 2019-12-06 19:24:14
UVM中的类包括：基类(base)------------uvm_void/uvm_object/uvm_transaction/uvm_root/uvm_phase/uvm_port_base 报告(reporting)--------uvm_report_object/uvm_report_handler/uvm_report_server/uvm_report_catcher Factory---------uvm_*_register/uvm_factory 配置(config)------uvm_resource/uvm_resoure_db/uvm_config_db sequencer--------uvm_sequencer_base/uvm_sequencer_param/uvm_squencer/uvm_push_sequencer sequence--------uvm_sequence_item/uvm_sequence_base/uvm_sequence sychronization------uvm_event/uvm_event_callback/uvm_barrier/uvm_objection/uvm_heartbeat containers----------uvm_pool/uvm_queue TLM component--------uvm

Why can't I use virtual/override on class variables as I can on methods?

由 浪子不回头ぞ 提交于 2019-12-06 18:31:26
问题 In the following example I am able to create a virtual method Show() in the inherited class and then override it in the inheriting class. I want to do the same thing with the protected class variable prefix but I get the error: The modifier 'virtual' is not valid for this item But since I can't define this variable as virtual/override in my classes, I get the compiler warning : TestOverride234355.SecondaryTransaction.prefix' hides inherited member 'TestOverride234355.Transaction.prefix'. Use

Virtual methods without body

由 点点圈 提交于 2019-12-06 16:48:10
问题 I was looking at some code in an abstract class: public virtual void CountX(){} public virtual void DoCalculation() { ...code} Why should I declare an empty virtual method in an abstract class if it is not mandatory to override it in derived types? 回答1: As @Adam told you, there are many cases in which it makes sense. When you create an abstract class, it's because you want to create a common interface for all classes deriving from that one; however, at that level of inheritance you won't have

WLC-Virtual Interface IP

由 可紊 提交于 2019-12-06 16:22:30
关于思科WLC，有很多接口类型，如下所示，这里主要针对Virtual IP记录一些最佳实践建议。 思科WLC的Virtual IP地址的作用： • Mobility management • DHCP中继 • Embedded L3安全（如Guest Web认证和VPN终止） • 它还启用了第3层Web授权时，维护第3层安全和移动性管理器（mobility managers）使用的DNS网关主机名，以验证证书的来源 主要作用： 1. 充当客户端DHCP过程的placeholder 2. 充当Web认证登录页面的重定向地址 Virtual IP限制： 1. 该地址是用作Client和WLC之间交流 2. 该地址不会显示为从分布式端口到分布式系统网络的源地址或目的地址 3. 为了使得系统正常运行，该地址必须被设置（不能为0.0.0.0） 4. 网络上的任何其他设备的IP都不能和该IP地址相同 5. 该IP地址不可ping通，且不应该存在在网络中的任何路由表中 6. 该IP无法映射到物理端口 7. 如果在mobility group情况下，所有的WLC都需要配置同样的Virtual IP，否则，WLC间漫游无法handoff完成，客户端会在一段时间断开连接 通常情况下，我们可能配置的virtual IP是1.1.1.1，但是这已经不是目前建议的最佳配置，参考如下： Virtual

Creating clone of an object not working with virtual base class

由 断了今生、忘了曾经 提交于 2019-12-06 16:09:28
问题 #include<iostream> using namespace std; class Something { public: int j; Something():j(20) {cout<<"Something initialized. j="<<j<<endl;} }; class Base { private: Base(const Base&) {} public: Base() {} virtual Base *clone() { return new Base(*this); } virtual void ID() { cout<<"BASE"<<endl; } }; class Derived : public Base { private: int id; Something *s; Derived(const Derived&) {} public: Derived():id(10) {cout<<"Called constructor and allocated id"<<endl;s=new Something();} ~Derived()

Size of classes with virtual functions GCC/Xcode

由 只愿长相守 提交于 2019-12-06 14:21:28
问题 Can anyone explain to me what is going on here? First off, I think most programmers know that a class with a virtual function has a vtbl and thus has 4 extra bytes on the top of it. As far as I know, that's fairly standard. I've tested this and taken advantage of this fact before to do load in place from a binary file with patched vtbls. For the last 6 months, I've been working in Xcode and just recently came across the need to do some load in place stuff, so I was looking into patching vtbls

第52课.c++中的抽象类和接口

由 徘徊边缘 提交于 2019-12-06 14:14:02
1.什么是抽象类 a.可用于表示现实世界中的抽象概念 b.是一种只能定义类型，而不能产生对象的类 c.只能被继承被重写相关函数 （不能创建对象，只能用于继承，可以用来定义指针） d.直接特征是 相关函数没有完整的实现 2.抽象类与纯虚函数 a.c++语言中没有抽象类的概念 b.c++中通过纯虚函数实现抽象类 c.纯虚函数是指只定义原型的成员函数 d.一个c++类中只要存在纯虚函数这个类就成为了抽象类 eg. 纯虚函数语法规则： class Shape { public: virtaul double area () = 0; }; //这里" = 0"用于告诉编译器当前是声明纯虚函数，因此不需要定义函数体 eg： #include <iostream> #include <string> using namespace std; class Shape { public: virtual double area () = 0; }; class Rect : public Shape { int ma; int mb; public: Rect (int a, int b) { ma = a; mb = b; } double area () { return ma * mb; } }; class Circle : public Shape { int mr; public:

Can the implementation of a virtual function be put in the header file

由 时光怂恿深爱的人放手 提交于 2019-12-06 13:01:41
usually if we put an implementation of a non-virtual member function in the header file that function would be inlined. how about if we put the implementation of a virtual member function in the header file? I guess it would be the same as putting it in the cpp file because inlining and polymorphism do not work together. Am I right on this? Putting the implementation of a method in the header file doesn't make it inline. Putting it in the class declaration does. I'll assume that's what you meant from now on. What is important here is that declaring a function inline is only an information to

Polymorphism without virtual in C++ for multi level inheritance

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-06 11:50:01
I have a situation where I need to achieve polymorphism without vtable. Here is what I am trying to do There is a class hierarchy: C extends B, B extends A The idea is to declare a function pointer in A and constructors of B and C assign their corresponding methods to the function pointer in A With the code below I am able to achieve polymorphism for class C but not for class B. Obviously I am missing something here. I am not sure if this is even possible. Greatly appreciate any insights into this problem. I can do this with the below code A<C> *c = new C(); c->BasePrint(); //Reached C's Print
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