c++

WinForm-style Invoke() in unmanaged C++

I've been playing with a DataBus-type design for a hobby project, and I ran into an issue. Back-end components need to notify the UI that something has happened. My implementation of the bus delivers the messages synchronously with respect to the sender. In other words, when you call Send(), the method blocks until all the handlers have ...

Referencing a union inside a structure using union tag gives incorrect address

I had a need to declare a union inside a structure as defined below: struct MyStruct { int m_DataType; DWORD m_DataLen; union theData { char m_Buff [_MAX_PATH]; struct MyData m_myData; } m_Data; }; Initially, I tried accessing the union data as follows (before I added the m_Data declaration):...

understanding a Build c++

I think I know what a build is. But I am not sure. My definition of a build is another word for saying compiled application. Can someone please tell me what exactly a build is. And why do people ask for 3 types of builds. Such as Debug Build, Profile Build and a Release Build. What are the differences. [edit] the types of builds ...

Creating a good directory structure

This might be a silly question but I am still learning. I have read several books on creating application and creating a good directory structure. When people talk about creating a directory structure, do they mean the folders you make within the solution explorer (folders you actually find inside of a .sln file) or do they mean setting ...

how to call a dll file in c. I want to transmit a xml file to it.

I found many ways, but they are too easy, they always get a return-value from the dll file. dll file: a file with the sufix ".dll" ...

C++ modularization framework (like OSGI) ?

I found one SOF http://www.codeproject.com/KB/library/SOF_.aspx , Are there anyother stable frameworks for modularization in C++ ? ...

Passing enums to functions in C++

Hi all, I have a header file with all the enums listed (#ifndef #define #endif construct has been used to avoid multiple inclusion of the file) that I use in multiple cpp files in my application.One of the enums in the files is enum StatusSubsystem {ENABLED,INCORRECT_FRAME,INVALID_DATA,DISABLED}; There are functions in the applicati...

Difference between const reference and normal parameter

void DoWork(int n); void DoWork(const int &n); Whats the diff ...

Adding python script to c++ project

How would I go about adding a script written in python to a c++ project? Thanks Edit: Basically all the script does is email some data. I would like to pass the data and maybe the email address to a function written in python. Hope that clears things up.. ...

C++ vector<T>::iterator operator +

Hi, Im holding an iterator that points to an element of a vector, and I would like to compare it to the next element of the vector. Here is what I have Class Point{ public: float x,y; } //Somewhere in my code I do this vector<Point> points = line.getPoints(); foo (points.begin(),points.end()); where foo is: void foo (Vector<Poi...

C++ Template Class Constructor with Variable Arguments

Is it possible to create a template function that takes a variable number of arguments, for example, in this Vector< T, C > class constructor: template < typename T, uint C > Vector< T, C >::Vector( T, ... ) { va_list arg_list; va_start( arg_list, C ); for( uint i = 0; i < C; i++ ) { m_data[ i ] = va_arg( arg_list, T...

Setting span html element text in C++

Hi, I am writing firefox extension using C++. I want to set text of the span html element. In Javascript, I used 'textcontent' javascript property to set span element text. How can I do it in C++? I found nsIDOMHTMLElement interface & its child interfaces. They seem useful. I am not getting the way in which I will use nsIDOMHTMLEle...

Can I use dll in Turbo C++ program and do we have any dll for lzw compression and decompression

I was trying to create a lzw compression program. But i need to finish it by today itself so i want to use some dll for taking my input as txt file and output to as a text file. I want to do this in TURBO C++ code which are doing my remaining functionalities. Can anyone suggest me some method. ...

How to compile a C++ source code written for Linux/Unix on Windows Vista (code given)

I have a c++ source code that was written in linux/unix environment by some other author. It gives me errors when i compile it in windows vista environment. I am using Bloodshed Dev C++ v 4.9. please help. #include <iostream.h> #include <map> #include <vector> #include <string> #include <string.h> #include <strstream> #include <unistd...

Are Multiple singleton instances possible in a shared DLL?

I am going to develop a DLL for an MFC Application, and suppose I have a singleton class in this DLL with some synchronization mechanism. And this DLL is used by other processes, namely EXEs. The question is: is this singleton created only once for all sharing processes or every process has its own singleton? And How can I solve this mu...

Why is the destructor of the class called twice ?

Apologies if the question sounds silly, I was following experts in SO and trying some examples myself, and this is one of them. I did try the search option but didn't find an answer for this kind. class A { public: A(){cout<<"A Contruction"<<endl;} ~A(){cout<<"A destruction"<<endl;} }; int main() { vector<A> t;...

SetWindowLong in CustomDraw causes unhandled exception

Hello, I am making some changes to a CSliderCtrl using the Custom Draw, the control is to be used in a dialog. Here is the structure: In my MessageMap I have : ON_NOTIFY_REFLECT_EX(NM_CUSTOMDRAW, OnNMCustomdraw) The OnNMCustomdraw method looks like the following: BOOL CCustomSliderCtrl::OnNMCustomdraw(NMHDR *pNMHDR, LRESULT *pResult) ...

What can explain std::cout not to display anything ?

For whatever reason, std::cout does not display anything with my application. The description of my development environment follows. I am working on a Qt application using Qt Creator. Since Qt Creator can't be launched from my station (XP64), i am currently developping it with Visual Studio 2008 and the Qt plugin (by importing the .pro ...

Using an array in embedded x86 assembly??

Hey all I have a method (C++) that returns a character and takes an array of characters as its parameters. I'm messing with assembly for the first time and just trying to return the first character of the array in the dl register. Here's what I have so far: char returnFirstChar(char arrayOfLetters[]) { char max; __asm { push eax...

Polymorphic functions with parameters from a class hierarchy

Let's say I have the following class hierarchy in C++: class Base; class Derived1 : public Base; class Derived2 : public Base; class ParamType; class DerivedParamType1 : public ParamType; class DerivedParamType2 : public ParamType; And I want a polymorphic function, func(ParamType), defined in Base to take a parameter of type Deriv...