c++

Memory not being freed, causing giant memory leak

Unfortunately the solutions have not worked yet; setting result.values pointer to 0 doesn't actually relieve the memory usage. I've also tried free(result.values) in place of that, but that is not desired as that deletes my string. Edit 2: I'll try writing a stack destructor. Edit 3: Gotcha. Thanks DeadMG, writing a destructor that fre...

NS2, Otcl: using a variable of an owned instance within a class

Hello all, I'm using NS2 to create some new classes in C++ and then link them to otcl. The linkage and everything works, but when I try to use the otcl variables in an object, I'm having a trouble. For example, suppose I have a class "Node" with the variable X. In the code I want to set this value and later on use it in some if-stateme...

C++ Class Static variable problem - C programmer new to C++

Hi guys, I am a C programmer, but had learnt C++ @school longtime back. Now I am trying to write code in C++ but getting compiler error. Please check and tell me whats wrong with my code. typedef class _filter_session { private: static int session_count; /* Number of sessions count -- Static */ public: _filter_session(); ...

Performance of vector::size() : is it as fast as reading a variable?

I have do an extensive calculation on a big vector of integers. The vector size is not changed during the calculation. The size of the vector is frequently accessed by the code. What is faster in general: using the vector::size() function or using helper constant vectorSize storing the size of the vector? I know that compilers usually a...

signature output operator overload

hi, do you know, how to write signature of a function or method for operator<< for template class in C++? I want something like: template <class A> class MyClass{ public: friend ostream & operator<<(ostream & os, MyClass<A> mc); } ostream & operator<<(ostream & os, MyClass<A> mc){ // some code return os; } But this just won't ...

What's the best way to resolve this scope problem?

I'm writing a program in python that uses genetic techniques to optimize expressions. Constructing and evaluating the expression tree is the time consumer as it can happen billions of times per run. So I thought I'd learn enough c++ to write it and then incorporate it in python using cython or ctypes. I've done some searching on st...

C++: Help with cin difference between Linux and Windows

I have a Win32 console program that I wrote and it works fine. The program takes input from the user and performs some calculations and displays the output - standard stuff. For fun, I am trying to get the program to work on my Fedora box but I am running into an issue with clearing cin when the user inputs something that does not match ...

is there a simple timed lock algorithm avoiding deadlock on multiple mutexes?

C++0x thread library or Boost.thread define a non-member variadic template function that locks all mutex at once that helps to avoid deadlock. template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...); The same can be applied to a non-member variadic template function try_lock_until, which locks all the mutex until a giv...

Is there a way to access the locale used by gettext under windows ?

I have a program where i18n is handled by gettext. The program works fine, however for some reason I need to know the name of the locale used by gettext at runtime (something like 'fr_FR') under win32. I looked into gettext sources, and there is a quite frightening function that computes it on all platforms (gl_locale_name, in a C file ...

Writing a program which uses voice recogniton... where should I start?

Hello! I'm a design student currently dabbling with Arduino code (based on c/c++) and flash AS3. What I want to do is to be able to write a program with a voice control input. So, program prompts user to spell a word. The user spells out the word. The program recognizes if this is right, adds one to a score if it's correct, and correct...

+= Overloading in C++ problem.

I am trying to overload the += operator for my rational number class, but I don't believe that it's working because I always end up with the same result: RationalNumber RationalNumber::operator+=(const RationalNumber &rhs){ int den = denominator * rhs.denominator; int a = numerator * rhs.denominator; int b = rhs.numerator * d...

Question about Virtual Inheritance hierarchy

Hi there: I encounter this problem when tackling with virtual inheritance. I remember that in a non-virtual inheritance hierarchy, object of sub-class hold an object of its direct super-class. What about virtual inheritance? In this situation, does object of sub-class hold an object of its super-class directly or just hold a pointer poi...

Virtual class problem

What i think about virtual class is, if a derived class has a public base, let's say, class base, then a pointer to derived can be assigned to a variable of type pointer to base without use of any explicit type conversion. But what if, we are inside of base class then how can we call derived class's functions. I will give an example: cl...

Lua + SWIG Monkey Patching

I have used SWIG to bind a set of classes to lua. I know C++ itself doesn't support monkey patching, and I'm not trying to modify my C++ objects, merely their lua representations. The problem comes if I want to start monkey patching the lua tables and objects exported by SWIG, so that I can modify the API presented on the lua side. e.g....

Is std::ifstream thread-safe & lock-free?

I intend to perform opening for reading a single file from many threads using std::ifstream. My concern is if std::ifstream is thread-safe & lock-free? More details: I use g++ 4.4 on Ubuntu & Windows XP, 4.0 on Leopard. Each thread creates its own instance of std::ifstream Thanks in advance! ...

printing double in binary

In 'Thinking in C++' by Bruce Eckel, there is a program given to print a double value in binary. (Chapter 3, page no. 189) int main(int argc, char* argv[]) { if(argc != 2) { cout << "Must provide a number" << endl; exit(1); } double d = atof(argv[1]); unsigned char* cp = reinterpret_cast<unsigned char*>(&...

Problem using delete[] (Heap corruption) when implementing operator+= (C++)

I've been trying to figure this out for hours now, and I'm at my wit's end. I would surely appreciate it if someone could tell me when I'm doing wrong. I have written a simple class to emulate basic functionality of strings. The class's members include a character pointer data (which points to a dynamically created char array) and an ...

How to compile OpenGL with a python C++ extension using distutils on Mac OSX?

When I try it I get: ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/cscalelib.so, 2): Symbol not found: _glBindFramebufferEXT Referenced from: /Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/cscalelib.so Expected in: dynamic lookup I've tried a...

C++ socket protocol design issue (ring inclusion)

So I have these two classes, mpqs_client and client_protocol. The mpqs_client class handles a Boost socket connection to a server (sending and receiving messages with some specific format. Upon receiving a message, it calls a static method, parse_message(..), in the class client_protocol, and this method should analyse the message receiv...

Reading function pointer syntax

Everytime I look at a C function pointer, my eyes glaze over. I can't read them. From here, here are 2 examples of function pointer TYPEDEFS: typedef int (*AddFunc)(int,int); typedef void (*FunctionFunc)(); Now I'm used to something like: typedef vector<int> VectorOfInts ; Which I read as typedef vector<int> /* as */ VectorOfInt...