c++

Displaying map stl

Declared a map early on: map<char*,char*> rtable; // used to store routing information Now I'm attempting to display the contents of the map: void Routes::viewroutes(){ typedef map<char*, char*>::const_iterator iter; for (iter=rtable.begin(); iter != rtable.end(); ++iter) { cout << iter->second << " " << iter->firs...

C++ traits question

I have a templated class template <typename Data> class C { ..... } In most situations, I depend on the compiler to let me substitute types for Data. I call methods foo(), goo() on objects of type Data, so what I substitute needs to provide that. I now need to substitute int and string for my Data type. I do not want to specialize ...

How to Access a Private Variable?

This question isn't meant to sound as blatantly insulting as it probably is right now. This is a homework assignment, and the spec sheet is scarce and poorly designed to say the least. We have a function: double refuel( int liter, GasStation *gs ) { // TODO: Access private variable MaxFuel of gs and decrement. } Sound simple enou...

Algorithm to convert RGB to HSV and HSV to RGB?

I'm looking for an efficient C or C++ algorithm that can convert RGB to HSV and vice versa. Thanks ...

The LoadLibraryA method returns error code 1114 (ERROR_DLL_INIT_FAILED) after more than 1000 cycles of loading/unloading.

Hi, I'm programing on C++, I'm using Visual Studio 2008, Windows XP, and I have the following problem: My application, that is a DLL that can be used from Python, loads an external dll, uses the required methods, and then unloads this external Dll. It's working properly, but after more than 1000 cycles the method "LoadLibraryA" returns ...

Open Source Simple Speech Recognition in C++ in Windows

Hey Everyone, I was wondering, are there any basic speech recognition tools out there? I just want something that can distinguish the difference between "yes" and "no" and is reasonably simple to implement. Most of the stuff out there seems to make you start from scratch, and I'm looking for something more high level. Thanks! ...

g++ linker can't find const member function

I have a Point class (with integer members x and y) that has a member function withinBounds that is declared like so: bool withinBounds(const Point&, const Point&) const; and defined like this: bool Point::withinBounds(const Point& TL, const Point& BR) const { if(x < TL.getX()) return false; if(x > BR.getX()) return false; ...

How to create pulsating value from 0..1..0..1..0 etc for a given duration?

Hi I'm working on some code where I have a Time object with a member time. Time.time gives me the time since my application started in seconds (float value). Now I want to create a pulsating value between 0 and 1 and then from 1 to 0 again, which continues doing thins untill the application stops. I was thinking to use sin() but don't...

How to composite argb image data on top of xrgb image data

I have a pointer to an 32bit argb image's pixel data and a 32bit xrgb image's pixel data. How can I composite the argb on top of xrgb image while making use of the alpha component? Visual Studio 2008 C++ Edit: Is there a quicker (faster processing) way to do the compositing than this: float alpha = (float)Overlay[3] / 255; ...

What is the motivation behind c++0x lambda expressions?

I am trying to find out if there is an actual computational benefit to using lambda expressions in c++, namely "this code compiles/runs faster/slower because we use lambda expressions" OR is it just a neat development perk open for abuse by poor coders trying to look cool? Thanks. PS. I understand this question may seem subjective but ...

wxWidgets running on other machine

Hello, I created application which uses wxWidgets library using visual studio 2008. Now I would like to create version which may be run on other machine. Because right now when I want to run It on another machine there is an error: the application failed to start because its side-by-side configuration is incorrect. What can I do to m...

Common protected data member in base class?

I have a base class and several derived classes. The derived classes use some common data, can I just put those common data as protected member of the base class? I know the protected member breaks encapsulation sometimes, so I wonder if there is any good approach. Here is a specific example: class Base{ public: virtual void foo() ...

Simple change results in make: Error 1

Had this: rtable.insert ( pair<string,string>(destination,nhop) ); // route insertion return 0; Changed it to this: if (rtable.insert ( pair<string,string>(destination,nhop)) == 0){ return 0; } First one compiles fine. Second one gives me a make error 1. I can go back and forth all day -- I can't see any issues. Any ideas? ...

Alternative to COM blind aggregation in .NET for class with private interface

When extending a COM class in unmanaged C++ where the original class has private interfaces, one way to do this is through the concept of blind aggregation. The idea is that any interface not explicitly implemented on the outer aggregating class is 'blindly' forwarded to the inner aggregated class. Now .NET as far as I can figure out do...

Portable C++ library for IPC (processes and shared memory), Boost vs ACE vs Poco?

Hi, I need a portable C++ library for doing IPC. I used fork() and SysV shared memory until now but this limits me to Linux/Unix. I found out that there are 3 major C++ libraries that offer a portable solution (including Windows and Mac OS X). I really like Boost, and would like to use it but I need processes and it seems like that this...

how do I use an enum value on a switch statement in C++

I would like to use an enum value for my switch statment in C++. Is it possible to use the enum values enclosed in the "{}" as choices for the "switch()"? I know that switch() needs an integer value in order to direct the flow of programming to the appropriate case number. If this is the case, do I just make a variable for each constant ...

Winsock WSAAsyncSelect sending without an infinite buffer

Hi, This is more of a design question than a specific code question, I'm sure I am missing the obvious, I just need another set of eyes. I am writing a multi-client server based on WSAAsyncSelect, each connection is made into an object of a connection class I have written which contains associated settings and buffers etc. My question...

cannot receive UDP broadcast packets

Hello I have 2 boxes: - an embedded device (ARM Omap with linux) which I'll call "Omap". - a PC (can either be Windows or linux). Scenario 1 Both boxes are in the same network (example: my office). The Omap gets its address from a DHCP server (ex: 192.168.10.110). The PC has always the same address (ex. 192.168.10.104). I can succ...

difference between -> and . for member selection operator.

Possible Duplicate: what is the difference between (.) dot operator and (->) arrow in c++ in this book i have I'm learning pointers, and i just got done with the chapter about OOP (spits on ground) anyways its telling me i can use a member selection operator like this ( -> ). it sayd that is is like the "." except points to ob...

How to use the callback method with a c++ directshow sample grabber

I have a sample grabber hooked into my directshow graph, based on this example http://msdn.microsoft.com/en-us/library/dd407288(VS.85).aspx the problem is that it uses one shot and buffers. I want to continuously grab samples, and i'd rather have a callback than i guess polling for the samples. How do use the SetCallback method? SetCa...