C++ (Non Visual C++ Issues) | Forum profile

Hello! I have been searching Google for hours and can't seem to figure this out. I have the following the stuct which contains a lot of different values. Let's say that each struct is about 400 bytes. struct table_row { char name[255]; unsigned int id, status; ... etc. }; Now lets say I create an array of 100,000 pointers, each pointing to a struct allocated in ...

hello i am trying to create a program for a assingment for my course and i cant see where i am going wrong. the program was written in Bloodshed Dev-C++ version 4.9.9.2. the program is meant to allow a user to either A) enter a name and have it saved into a text file or B) allow a user to retreave a name saved in that text document. it has a case switch to make the selection. ...

Good day Lets say I have Code: template <class T> void setMode (const std::vector &objParameters) { for(int i = 0; i < objParameters.size(); i++) { std::string str = objParameters[i]; std::cout<<str<<std::endl; } }; Why it still request to convert to string. As I understand string...

Hi Gurus, What is the preffered way to check if opening a file failed? I know about bad() but is there a better way, let's say one that I would actually know what was the failure ? Code: std::ofstream MyFile; MyFile.open("C:\\MyFile", std::ios_base::out | std::ios_base::out); if (MyFile.bad()) { // Failed to open the file } Using win32 CreateFile() make ...

longs are integers. So are shorts and chars. It's all a matter of how many bytes the particular system uses for each. What I put above is quite easily generalisable to any size of integer (and to remove the intermediate string): Code: template <typename int_type> void func(int_type val) { for (int i = sizeof(val); i > 0; --i) { int shift = 8*(i-1); // 8-bit bytes assumed!...

Consider Code: # include <limits> # include <iostream> /* -------------------------------------------------- ----------------------------- | class maybe -------------------------------------------------- ----------------------------- */ class unit_test_maybe ; // forward declarion of unit_test_maybe class maybe { friend class unit_test_maybe ; int m_dummy ; ...

Hi i am a beginner in C++ .. could any one explained the Title code.? Then what is the function of ' Trace' in c++?. virtual void function(const void *args)=0; Thank you.

Hi Gurus, What is the standard (and safest) way to format a string ? TCHAR szMessage[1024]; ??????? (_T("My message is HRESULT=%ld"), hr); so the result will be: szMessage = message is HRESULT=1032 Many thanks!

This year I'm getting a computer programming course in college. Since I've had some experience with programming I bought myself some books (Sam's Teach Yourself C++ and C++ For Mathematicians) to get ahead of class . But I find the way they teach c++ a bit strange. First of all they're using an outdated devc++ (4.970). And second, the code they use differs from what I've read in more recent...

disregard I posted this on the wrong site.. My apologies!

Hello! I have been searching Google for hours and can't seem to figure this out. I have the following the stuct which contains a lot of different values. Let's say that each struct is about 400 bytes. struct table_row { char name[255]; unsigned int id, status; ... etc. }; Now lets say I create an array of 100,000 pointers, each pointing to a struct allocated in ...

Personally, I find it easier to derive from std::logic_error or std::runtime_error and their derived classes instead of directly deriving from std::exception since it makes specifying the (default) error message somewhat easier. Besides, it also gives a better hint of what kind of exception you are defining.

Hi, May I know how to initialize a large constant array? I'm trying to do so by the following code: Code: const unsigned char tempary[1024]; memset(tempary, 0x5a, 1024); This compiles and runs perfectly, but when I run PC-Lint on it, it gives me a warning. How do I get rid of the warning w/o suppressing it? I'm involved in the project and one of the project requirements is 0 ...

Hi, I'm having difficulty finding a way to implement part of a matrix library I'm writing. Here's a distilled version of the code, to demonstrate the problem: Code: class Vector { public: virtual Vector *getTranspose() = 0; } class RowVector : public Vector { public: virtual ColumnVector *getTranspose(); } class ColumnVector : public Vector { public: ...

how to overload using operator+ with matrix example i enter in a1,a2,a3,a4 format then i enter another in b1,b2,b3,b4 format how to use operator+ to add this 2 together Code: #include <iostream> using namespace std; class matrix { public: matrix operator+(matrix); matrix(); matrix(int,int,int,int,int,int,int,int); friend ...

I am mainly a java programmer trying to learn some other languages. Does C++ have any built in data structures like java does? Which pre-processor directive are they located in? How do I use them?

Hello all is there any way to handle creation and general handling of directories and files in c++ ? ( with out external libraries ) or maybe pure C ? Thanks

I know that using auto_ptr in a *general* way inside a vector is bad. However, I am curious whether it might be acceptable in a vector which is never expected to be resized or copied. It seems like such a use should be fine.... My notion is: 1) Clear the vector whenever its size is to change. 2) Resize it. We should have a bunch of empty auto_ptrs. 3) Assign new'd pointers to some of them....

Hi I am newbie to C++. I have a problem with compiling my code. I installed the GSL library from Gnuwin32 in its default location (C:\Program Files\) and tried to compile a sample program form the GNU help manual. Although the code itself is not the problem, I have pasted it below. It seems like my Borland C++ compiler is unable to read the header files. HTML Code: #include <...

So I've never really learned much about compilers, and I was a little surprised to find the executables produced by these two code bits differ. Do they differ in a significant way? I always assumed the compiler treated the operator functions like most other functions. Is there some tool I can use on a linux box to examine in some way how they differ, i.e. is it only a few locations in the code...