c++

c++ passing unknown type to a function and any Class type definition

I am trying to create a generic class to write and read Objects to/from file. Called it ActiveRecord class only has one method, which saves the class itself: void ActiveRecord::saveRecord(){ string fileName = "data.dat"; ofstream stream(fileName.c_str(), ios::out); if (!stream) { cerr << "Error opening file: " << fileName << endl...

How can I debug an application crash in Win7 after it's happened?

I have a Visual Basic 6 application that I've recently changed to use a couple of C++ DLLs I've written in Visual Studio 2008. The application works fine on my PC, but when we install it on one of our test PCs it tends to crash during shutdown - we see the Win 7 message "Your application has failed" or whatever it is. I know Win 7 store...

Weird characters at the beginning of a LPTSTR? C++

I am using this code to get the windows version: #define BUFSIZE 256 bool config::GetOS(LPTSTR OSv) { OSVERSIONINFOEX osve; BOOL bOsVersionInfoEx; ZeroMemory(&osve, sizeof(OSVERSIONINFOEX)); osve.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX); if( !(bOsVersionInfoEx = GetVersionEx ((OSVERSIONINFO *) &osve)) ) ret...

C++ destructors causing crash's

ok, so i got a some what intricate program that simulates the uni systems of students, units, and students enrolling in units. Students are stored in a binary search tree, Units are stored in a standard list. Student has a list of Unit Pointers, to store which units he/she is enrolled in Unit has a list of Student pointers, to store st...

How to initialize all elements in an array to the same number in C++

I'm trying to initialize an int array with everything set at -1. I tried the following, but it doesn't work. It only sets the first value at -1. int directory[100] = {-1}; Why doesn't it work right? ...

Error with Phoenix placeholder _val in Boost.Spirit.Lex :(

Hello, everybody. I'm newbie in Boost.Spirit.Lex. Some strange error appears every time I try to use lex::_val in semantics actions in my simple lexer: #ifndef _TOKENS_H_ #define _TOKENS_H_ #include <iostream> #include <string> #include <boost/spirit/include/lex_lexertl.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #includ...

how to break the internet connection with code?

hey i know that on some computers you can cut off the wifi with a buttion and i want to do that with my desktop but it's not wireless. is there a way to in code block my computer from the internet then unblock later. anyway i can do this? ...

How does one write extconf.rb files when one extension includes header files from another?

This is a follow-up question for: Multiple Ruby modules under one directory What happens if these extensions include each other? For example, you have the following structure: ext/foo ext/bar In ext/bar/bar.h, you have a #include "foo.h" foo.h and foo.cpp compile to form foo.o, to make life a little more complicated. Finally, it ...

Including huge string in our c++ programs ?

I am trying to include huge string in my c++ programs, Its size is 20598617 characters , I am using #define to achieve it. I have a header file which contains this statement #define "<huge string containing 20598617 characterd>" When I try to compile the program I get error as fatal error C1060: compiler is out of heap space I tried...

handling large number

Hello, this is actually an problem question from project euler site http://projecteuler.net/index.php?section=problems&amp;id=3 Anyway I'm not out after the solution, but I probably guess you will know what my approach is. To my question now, how do I handle numbers exceeding unsigned int? Is there a mathematical approach for this, if ...

C++ error: ‘string’ has not been declared

In my header file I'm getting the error: ‘string’ has not been declared error but at the top of the file I have #include <string>, so how can I be getting this error? ...

undefined reference errors in C++

I have files Record.h and Record.cpp. When I just include the Record.h file, I get several undefined reference errors to functions defined in those files. When I also include Record.cpp then the errors go away. Why is that? Record.h has the forward declarations for the functions it says are an undefined reference. Record.h #ifndef RECO...

Pages used by a DLL in the address space of a process

Is there a reliable way to learn that a memory page or a range of pages belongs to a specific DLL inside the address space of a process? ...

How to fill a section within c++ string?

Having a string of whitespaces: string *str = new string(); str->resize(width,' '); I'd like to fill length chars at a position. In C it would look like memset(&str[pos],'#', length ); How can i achieve this with c++ string, I tried string& assign( const string& str, size_type index, size_type len ); but this seems to truncat...

Visual studio feature - commenting code Ctrl K - Ctrl C

I commented on this answer some time ago regarding how visual studio comments out code with // or /* */. I was thinking to revise the answer (to include my findings) but I had to test it first, which kind of confused me. My finding is that depending on what you comment when you press Ctrl - K, Ctrl - C you will get either // or /* */. ...

Finding the maximum weight subsequence of an array of positive integers?

I'm tring to find the maximum weight subsequence of an array of positive integers - the catch is that no adjacent members are allowed in the final subsequence. The exact same question was asked here, and a recursive solution was given by MarkusQ thus: function Max_route(A) if A's length = 1 A[0] else maximum of A[0]+Ma...

MySQL Connector Linker Problem

Hey, I'm trying to compile a program with the MySQL C++ Connector but somehow I can't get the linking right. The errors I get are: mysql/lib/libmysqlcppconn.so: undefined reference to `std::ios_base::ios_base()@GLIBCPP_3.2'.... etc locations: libmysqlcppconn.so: mysql/lib/ libmysqlclient.so: /usr/lib/ I tried to follow...

Closure and nested lambdas in C++0x

Using C++0x, how do I capture a variable when I have a lambda within a lambda? For example: std::vector<int> c1; int v = 10; <--- I want to capture this variable std::for_each( c1.begin(), c1.end(), [v](int num) <--- This is fine... { std::vector<int> c2; std::for_each( c2.begin(), ...

how to use a class method as a WIN32 application callback method (WINPROC)... Error static struct HINSTANCE__

I am receiving errors and at the same time trying to make this work so please read what I got to say. Thanks.... I am creating a c++ application and majority of the application is encapsulated into a class. That means that my WinProc function is a static class method that I use as my call back method for my win32 application. The proble...

bind() fails with windows socket error 10038

I'm trying to write a simple program that will receive a string of max 20 characters and print that string to the screen. The code compiles, but I get a bind() failed: 10038. After looking up the error number on msdn (socket operation on nonsocket), I changed some code from int sock; to SOCKET sock which shouldn't make a differe...