virtual

How does compiler optimize virtual methods implemented by a sealed class

由 对着背影说爱祢 提交于 2019-12-11 06:48:01
问题 I'm wondering how the following code is optimized. Specifically concerning virtual and direct calls. I have commented on how I think everything is optimized but those are just guesses. public abstract class Super { public abstract void Foo(); public void FooUser() { Foo(); } } public class Child1 : Super { public override void Foo() { //doSomething } } public class SealedChild : Super { public override void Foo() { //doSomething } } class Program { void main() { Child1 child1 = new Child1();

Upload Arduino code on virtual serial port through Arduino IDE

由 我是研究僧i 提交于 2019-12-11 05:36:41
问题 I downloaded several software that provide virtual COM ports. These COM ports do appear in the Device Manager and can be selected for upload from the Arduino IDE, menu Tools -> Serial Port -> COM3. It starts uploading and reaches 90% and then it either times out or just does nothing. I want to upload onto the virtual COM port so I could then read the compilation output files in another program. I don't want to use my Arduino at all, and I don't want to manually get the verbose output files

Windows Azure creating virtual directory to local storage

由 自古美人都是妖i 提交于 2019-12-11 04:09:08
问题 I need a help with creating virtual directory pointing to local storage in Windows Azure (production environment). I can set up a virtual directory manually but it is being erased every time Azure is restarted. The clue is to create the virtual directory via config file when I upload a package of my project on Azure. The question is how to create such directory so that it is pointing to local storage. Thx in advance for any suggestions. Best Regards, Darek 回答1: I suggest you create the

Avoiding virtual functions on embedded target

由 人走茶凉 提交于 2019-12-11 03:44:53
问题 I have a class Player that plays back data from a big block of memory that consists of a number of equal chunks. typedef char chunk_t[100]; typedef struct { chunk_t data[100] } blockOfMemory_t; The Player itself could theoretically work for different layouts and contents of data, so I would like to program it in a re-usable way. To do this, I thought of something like this: class Player { public: Player() { ... } virtual ~Player() { ... } void play() { for (int i = 0; i < getNumChunks(); i++)

Isn't 'virtual' keyword redundant when 'override' or 'final' specifiers are used?

由 我的梦境 提交于 2019-12-11 03:03:59
问题 Let's say I have the following base class: class Base { public: virtual void f() {}; }; If I want to write a class that will override the f() and will not allow to override it to it's derived classes can write it using following approaches: Approach 1: class Derived : public Base { public: virtual void f() override final {}; }; Approach 2: class Derived : public Base { public: void f() final {}; }; Approach 1 is a fully detailed when Approach 2 more compact and final still says that f() is

Is there a way to get the C++ virtual member function address

由 与世无争的帅哥 提交于 2019-12-11 02:54:39
问题 I searched this article: C++ : Getting function virtual 'address' with member function pointer In order to test if the virtual member function is usually at the beginning address of the object, I wrote the code as following: #include <pwd.h> #include <string.h> #include <stdio.h> class Base { public: int mBase1; char mBase2; virtual void foo() { fprintf(stderr,"Base foo called\n"); } }; class Child: public Base { public: int cc; virtual void foo() { fprintf(stderr,"Child foo called"); } };

Segfault when calling virtual function of derived class

由 拟墨画扇 提交于 2019-12-11 02:45:45
问题 I've been having a problem with segfaults when I call virtual function of a derived class. However, these segfaults do not occur if I change the name of the function to be different from the name of the virtual function in the base class. Here's some code: //in main //initialize scene objects //camera if((camera = (Camera*)malloc(sizeof(Camera))) == NULL){ cout << "Could not allocate memory for camera" << endl; } //...code in middle //inside file parsing... //infile is an ifstream /

Why doesn’t std::string have a virtual destructor?

由 可紊 提交于 2019-12-11 01:21:14
问题 When I was working on a project that involved defining sentences in a given language, I was surprised to discover that std::string destructor was not virtual. This made it a lot more difficult to specialize this class (I had to create a wrapper). Why did the standard committee decide to have this class not virtual? in /usr/lib64/gcc/x86_64-pc-linux-gnu/4.5.3/include/g++-v4/bits/basic_string.h, we have: template<typename _CharT, typename _Traits, typename _Alloc> class basic_string { ... /** *

Liferay: After changing Public Virtual Host settings, can't log in

由 橙三吉。 提交于 2019-12-11 01:01:22
问题 I did a mistake and seems like I can't fix it alone, if it can be fixed. I have the Liferay URL looking like this: http://192.168.10.10:8080/web/guest ; I wanted to remove the '/web/guest' part from the address so from Manage -> Settings wrote 192.168.10.10:8080 to the Public Virtual Host field. After saving it, I can't log in anymore. Everytime I write http://192.168.10.10:8080/login (as I did before), it goes to the index page and not the login page. Then if I write the login after 'web

VMware导出虚拟机到Oracle Virtual Box

由 霸气de小男生 提交于 2019-12-10 21:51:08
VMware导出虚拟机到Oracle Virtual Box 01 `VMware worktation Pro` 选中需要导出的虚拟机->打开菜单“文件”->“导出为OVF”->选择文件保存路径->保存->等待。。。->得到mf、ovf、vmdk和iso文件 02 `Oracle Virtual Box` 打开菜单“管理”->导入虚拟电脑->选择ovf文件->下一步->导入->等待。。。->得到虚拟机 03 `网卡设置-添加网卡` 选中导入的虚拟机->点“设置”或者右键后选设置->选网络->点击网卡2->勾选启用网络连接->连接方式选择“仅主机(host-only)网络”->混杂模式选择全部允许->勾选接入网线->点击OK 04 `启动虚拟机` ip a 【发现有3个网卡，而且有一个网卡没有ip地址】 service network restart 【重启网络失败】 05 `修改网络配置` cd /etc/sysconfig/network-scripts 【网络脚本目录】 ll|grep ifcfg 【发现有个ifcfg-ens32】 mv ifcfg-ens32 .. 【将ens32移到父目录，备份】 service network restart 【执行成功】 06 `为没有ip的网卡添加ip` ip addr add/delete <VirtualBox Host
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