Which approach is the better one and why? template<typename T> struct assistant { T sum(const T& x, const T& y) const { ... } }; template<typename T> T operator+ (const T& x, const T& y) { assistant<T> t; return t.sum(x, y); } Or template<typename T> struct assistant { static T sum(const T& x, const T& y) { ... } };...
We have a C++ (SOAP-based) web service deployed Using Systinet C++ Server, that has a single port for all the incoming connections from Java front-end. However recently in production environment when it was tested with around 150 connections, the service went down and hence I wonder how to achieve load-balancing in a C++ SOAP-based web ...
I'm implementing callback routines for external static C++ library to be used in Objective-C project. Now I have trouble moving data between callback and normal routines. As you can see below my "msgStore" is defined as part of MyMessage class and can be used within class routines such as init(). However attempting same from callback rou...
I have the following OpenGL code in the display function: glLoadIdentity(); gluLookAt(eyex, eyey, eyez, atx, aty, atz, upx, upy, upz); // called as: gluLookAt(20, 5, 5, -20, 5, 5, 0, 1, 0); axis(); glutWireCube (1.); glFlush (); axis() draws lines from (0,0,0) to (10,0,0), (0,10,0) and (0,10,0), plus a line from (1,0,0) to (1,3,0). ...
Hi Guys, I want to change from my program the speaker setup, which is under speaker settings / advanced... section. I tried to find maybe there is some sort of registry entry but no luck till now :| Any Ideas ? Thanks a lot ! ...
Why does compiler generate error? template<class T> void ignore (const T &) {} void f() { ignore(std::endl); } Compiler VS2008 gives the following error: cannot deduce template argument as function argument is ambiguous. ...
I had a small WTF moment this morning. Ths WTF can be summarized with this: float x = 0.2f; float y = 0.1f; float z = x + y; assert(z == x + y); //This assert is triggered! (Atleast with visual studio 2008) The reason seems to be that the expression x + y is promoted to double and compared with the truncated version in z. (If i change...
float f = 0.7; if( f == 0.7 ) printf("equal"); else printf("not equal"); Why output is -> not equal ???? Why is happens so ? ...
Do files or folders on S60 have some unique id value that can identify them? I would like to have an id that can be later used to extract full path of a file or folder. Is this achievable? If not, what would be the best way to keep track of files of interest? E.g. if I have a pdf reader, and I want to have a menu option to show all pd...
On Linux pwrite operation (which is seek+write) is atomic, meaning doing pwrite-s in multiple threads with one file descriptor is safe. I want to create file descriptor duplicate, using dup(). Now, having fd1 and fd2 - will pwrite-s work as expected, or there's danger of race condition? ...
Well, I think my problem originates in a lake of knowledge of basic C++ concepts. The problem is, in my code (below) I have the classes Header and Register. For both, I pass a reference to a ifstrem file already opened. The Header reads some bytes from it. Register has a method to return a reference of Header (which is passed in Register...
I'm trying to use a C library in a C++ app and have found my self in the following situation (I know my C, but I'm fairly new to C++). On the C side I have a collection of functions that takes a function pointer as their argument. On the C++ side I have objects with a functor which has the same signature as the function pointer needed b...
Can anyone please tell me that which type of sorting technique (bubble, insertion, selection, quick, merge, count...) is implemented in the std::sort() function defined in the <algorithm> header file in C++? ...
I suppose they are different, right? From a performance perspective, which is faster? Has anyone ever did some benchmarking ? Can I use them to pass data within the same process ? (i.e., among different threads) thanks! ...
This doesn't compile: template<class X> struct A { template<int I> void f() {} }; template<class T> void g() { A<T> a; a.f<3>(); // Compilation fails here (Line 18) } int main(int argc, char *argv[]) { g<int>(); // Line 23 } The compiler (gcc) says: hhh.cpp: In function 'void g()': hhh.cpp:18: error: expected ...
Hello, i have small problem understanding why my smart pointer class is leaking on self assing. If i do something like this SmartPtr sp1(new CSine());//CSine is a class that implements IFunction iterface sp1=sp1; my colleagues told me that my smart pointer leaks. I added some log messages in my smart pointer to track what is going on ...
What is the for loop doing? I just can't understand it. list<pair<int, double> > nabors; list<pair<int, double> >::iterator i; for (i = nabors.begin(); i != nabors.end() && dist >= i->second; i++); Thanks in advance ...
I'm in the middle of porting some c++ code to java, and I keep running across instances where whoever wrote it kept doing the following: double c = (1.0/(a+1.0)*pow(b, a+1.0)); double d = (1./(integral(gamma, dmax)-integral(gamma, dmin)))*(integral(gamma+1, dmax)-integral(gamma+1, dmin)); Instead of: double c = pow(b, a+1.0)/(a+1.0);...
I am trying ot add a function template that will print if it contains precision values or valves and the value. The rest of the program works except this function. I am not sure what I am doing wrong but the error I recieve is: error C2784: 'void printInstrumentDetail(const I *const )' : could not deduce template argument for 'const I *...
I'm trying input a phone number in the format: 555-555-5555 into a struct with three int's. I've tried using getline with a delimiter of "-", but I keep getting the error: "cannot convert parameter 1 from 'int' to 'char *'". I tried creating a temp char* variable to store the number in and then type casting it to int, but that didn't w...