Say I have: class A { public: static void DoStuff(); // ... more methods here ... }; And later on I have a function that wants to call DoStuff: B::SomeFunction(A* a_ptr) { Is it better to say: a_ptr->DoStuff(); } Or is the following better even though I have an instance pointer: A::DoStuff() } This is purely a matter of style, but I'd like to get some informed opin
说我有： class A { public: static void DoStuff(); // ... more methods here ... }; 后来我有一个想要调用DoStuff的函数： B::SomeFunction(A* a_ptr) { 是否更好地说： a_ptr->DoStuff(); } 或者，即使我有一个实例指针，以下更好： A::DoStuff() } 这纯粹是一种风格问题，但我想在作出决定之前得到一些明智的意见。 我想我更喜欢“A :: DoStuff（）”，因为更清楚的是正在调用静态方法。 最好
I have a lot of code like this: #define WITH_FEATURE_X struct A { #ifdef WITH_FEATURE_X // ... declare some variables Y #endif void f (); }; void A::f () { // ... do something #ifdef WITH_FEATURE_X // ... do something and use Y #else // ... do something else #endif // ... do something } and I'd like to replace the #defines with template parameters: template < int WITH_FEAT
我有很多这样的代码： #define WITH_FEATURE_X struct A { #ifdef WITH_FEATURE_X // ... declare some variables Y #endif void f (); }; void A::f () { // ... do something #ifdef WITH_FEATURE_X // ... do something and use Y #else // ... do something else #endif // ... do something } 我想用模板参数替换#define： template < int WITH_FEATURE_X > // can be 0 or 1 struct A; 但是我不想
I would like to send an http post request in c++. It seems like libcurl (Curlpp) is the way to go. Now, here is a typical request that am sending http://abc.com:3456/handler1/start?<name-Value pairs> The name values pairs will have: field1: ABC field2: b, c, d, e, f field3: XYZ etc. Now, I would like to know how to achieve the same using curlpp or libcurl. Code snippets will really
我想用c ++发送一个http post请求。 似乎libcurl（Curlpp）是要走的路。 现在，这是一个典型的发送请求 http://abc.com:3456/handler1/start?<name-Value pairs> The name values pairs will have: field1: ABC field2: b, c, d, e, f field3: XYZ etc. 现在，我想知道如何使用curlpp或libcurl来实现相同的功能。 代码片段确实有帮助。 没有Curlpp的经验，但这是我用libcurl做的。 您可以使用设置您的目标网
Can anyone help me to find out the top 1% (or say top 100 pixels)brightest pixels with their locations of a gray image in opencv. because cvMinMaxLoc() gives only brightest pixel location. Any help is greatly appreciated. 请尝试使用cvThreshold。 this is a simple yet unneficient/stupid way to do it: for i=1:100 get brightest pixel using cvMinMaxLoc store location set it to a value of
任何人都可以帮助我找出在opencv中灰度图像位置最高的1％（或称前100像素）最亮的像素。 因为cvMinMaxLoc（）只给出最明亮的像素位置。 任何帮助是极大的赞赏。 请尝试使用cvThreshold。 这是一个简单而不够/愚蠢的做法： for i=1:100 get brightest pixel using cvMinMaxLoc store location set it to a value of zero end 如果你不介意效率这应该工作。 您还应该检查cvInRangeS以查找定义低阈值和高阈值的其他
We are compiling an embedded C/C++ application that is deployed in a shielded device in an environment bombarded with ionizing radiation. We are using GCC and cross-compiling for ARM. When deployed, our application generates some erroneous data and crashes more often than we would like. The hardware is designed for this environment, and our application has run on this platform for several year
我们正在编译一个嵌入式C / C ++应用程序，该应用程序部署在屏蔽设备中的电离辐射轰炸环境中。 我们正在使用GCC并针对ARM进行交叉编译。 部署时，我们的应用程序会产生一些错误的数据，并且会比我们想要的更频繁地崩溃。 硬件是为这种环境设计的，我们的应用程序已经在这个平台上运行了好几年。 我们可以对我们的代码进行更改，还是可以通过编译时改进来识别/纠正由单个事件冲突引起的软错误和内存损坏？ 是否有其他开发人
EDIT I switched from memcmp to a home brewed 13 byte compare function and the homebrew doesnt have the extra instructions. So all I can guess is that the extra assembly is just a flaw in the optimizer. if (!EQ13(&ti, &m_ti)) { // in 2014, memcmp was not being optimzied here 000007FEF91B2CFE mov rdx,qword ptr [rsp] 000007FEF91B2D02 movzx eax,byte ptr [rsp+0Ch] 0000
编辑 我从memcmp切换到家庭酿造的13字节比较功能，并且自制软件没有额外的指令。 所以我只能猜测，额外的组装只是优化器中的一个缺陷。 if (!EQ13(&ti, &m_ti)) { // in 2014, memcmp was not being optimzied here 000007FEF91B2CFE mov rdx,qword ptr [rsp] 000007FEF91B2D02 movzx eax,byte ptr [rsp+0Ch] 000007FEF91B2D07 mov ecx,dword ptr [rsp+8] 000007FEF91B2D0B cmp
I'm seeing 15% performance degradation of the same C++ code compiled to exactly same machine instructions but located on differently aligned addresses. When my tiny main loop starts at 0x415220 it's faster then when it is at 0x415250. I'm running this on Intel Core2 Duo. I use gcc 4.4.5 on x86_64 Ubuntu. Can anybody explain the cause of slowdown and how I can force gcc to optimal
我看到相同的C ++代码编译为完全相同的机器指令，但位于不同对齐的地址上的性能下降了15％。 当我的微小主循环从0x415220开始时，它的速度快于0x415250。 我在Intel Core2 Duo上运行这个。 我在x86_64 Ubuntu上使用gcc 4.4.5。 任何人都可以解释放缓的原因，以及我可以如何强制gcc优化对齐循环？ 以下是使用Profiler注释对两种情况进行反汇编： 415220 576 12.56% |XXXXXXXXXXXXXX 48 c1 eb 08 s
I don't understand the program which is shown below. #include<stdio.h> #include<sys/types.h> #include<malloc.h> main() { int *i1, *i2; char *s; printf("sbrk(0) before malloc(4): 0x%xn", sbrk(0)); i1 = (int *) malloc(4); printf("sbrk(0) after `i1 = (int *) malloc(4)': 0x%xn", sbrk(0)); i2 = (int *) malloc(4); printf("sbrk(0) after `i2 = (int *) ma
我不明白下面显示的程序。 #include<stdio.h> #include<sys/types.h> #include<malloc.h> main() { int *i1, *i2; char *s; printf("sbrk(0) before malloc(4): 0x%xn", sbrk(0)); i1 = (int *) malloc(4); printf("sbrk(0) after `i1 = (int *) malloc(4)': 0x%xn", sbrk(0)); i2 = (int *) malloc(4); printf("sbrk(0) after `i2 = (int *) malloc(4)': 0x%xn", sbrk(0));
I am having some difficulty compiling a C++ program that I've written. This program is very simple and, to the best of my knowledge, conforms to all the rules set forth in the C++ Standard. I've read over the entirety of ISO/IEC 14882:2003 twice to be sure. The program is as follows: Here is the output I received when trying to compile this program with Visual C++ 2010: c:dev>c
编写我编写的C ++程序时遇到一些困难。 该程序非常简单，并且据我所知，符合C ++标准中规定的所有规则。 我已经仔细阅读了两次ISO / IEC 14882：2003的全部内容。 该计划如下： 以下是我在尝试使用Visual C ++ 2010编译此程序时收到的输出： c:dev>cl /nologo helloworld.png cl : Command line warning D9024 : unrecognized source file type 'helloworld.png', object file assumed helloworld.png : fatal error L
When my C++ program crashes I would like it to automatically generate a stacktrace. My program is being run by many different users and it also runs on Linux, Windows and Macintosh (all versions are compiled using gcc ). I would like my program to be able to generate a stack trace when it crashes and the next time the user runs it, it will ask them if it is ok to send the stack trace to me so
当我的C ++程序崩溃时，我希望它自动生成一个堆栈跟踪。 我的程序由许多不同的用户运行，它也运行在Linux，Windows和Macintosh上（所有版本都使用gcc ）。 我希望我的程序能够在崩溃时生成堆栈跟踪，并且在用户下次运行堆栈跟踪时，它会询问他们是否可以将堆栈跟踪发送给我，以便我可以跟踪问题。 我可以处理发送给我的信息，但我不知道如何生成跟踪字符串。 有任何想法吗？ 对于Linux，我相信Mac OS X，如果您使用gcc或