C / C++ / MFC

Austrian_Programmer wrote:

When I try to execute the program a runtime error occurs saying that there is a null-reference exception in the line list[c] = strtok(str, delimiters);. To ensure that there is enough free memory I even used the new operator.

char* exmp = "I have a problem!";

char exmp[] = "I have a problem!";

1. Look at the strtok documentation[^] - you only pass in str on the first call to strtok for that string - the rest of the time, you pass in NULL.
2. The loop condition in str2list is all wrong. list is a char**, so sizeof(list)/sizeof(char*) will be equal to 1. If you want to be safe with respect to the size of list, you need to explicitly pass it in - C/C++ doesn't pass around array sizes with arrays.
3. Similarly, the loop condition in _tmain is wrong (although this problem goes away if you take note of the next point).
4. There's no point using new when you have a fixed array size - declaring arglist with char* arglist[16]; will work just as well.
5. I'm...interested that you use char as the type of the loop variables
6. Although the for loop in str2list may compile with the compiler you're using, it won't with VS2008 (and possibly won't with earlier compilers), and isn't compliant with the C++ standard - going by the standard, your loop variable isn't accessible outside the loop.
7. You return the number of tokens in the list from str2list...and then don't use it. Mmmmm.

#include <iostream>
#include <string.h>

using namespace std;

int str2list(char* str, char** list, int maxTokenCount, const char* delimiters)
{
   for (int c = 0; c<maxtokencount;>   {
      list[c] = strtok(str, delimiters);
      if (list[c] == NULL) return c;
      str = 0;
   }
}

int main()
{
   char* arglist[16] = {0};
   char exmp[] = "I have a problem!";
   const int numToks = str2list(exmp, arglist, 16, " ");
   for (int c = 0; c < numToks; c++)
   {
      cout << arglist[c] << endl;
   }
   return 0;
}

#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <algorithm>
#include <iterator>

using namespace std;

vector<string> split(string const& exmp)
{
   istringstream s(exmp);
   return vector<string>(istream_iterator<string>(s), istream_iterator<string>());
}

int main()
{
   string exmp = "I have a problem!";
   const vector<string> toks = split(exmp);
   
   copy(toks.begin(), toks.end(), ostream_iterator<string>(cout, "\n"));

   return 0;
}

Austrian_Programmer wrote:

Normally I use C++ for game programming and mathematical things and that's more or less the first time I do something with strings in C++, so this is all in all just a try.

Hiigara wrote:

What technologies/libraries/protocols I need to study to develop a video system

Hiigara wrote:

I prefer coding in C++.

ScotDolan wrote:

Where does the dll get it's runtime priority? Is it from the calling appication or do i have to sent it myself.

ForNow wrote:

Just so that I understand the dervied base concept

ForNow wrote:

I ended up allocating the storage required on the Heap

myeventptr = HeapAlloc(GetProcessHeap(),0,sizeof(MyEvent))

and the then kicking of the constructer via myeventptr->MyEvent::MyEvent(....);

is this going to create the object for me ???

ForNow wrote:

well actually make a global copy of it via the new operator on the Heap available For the entire app

Myevent& GetMyEvent();

Myevent& GetMyEvent()
{
   static Myevent theOnlyMyevent;
   return theOnlyMyevent;
}

class Myevent : public CEvent
{
public:
   static Myevent& GetMyEvent();
   your stuff
private:
   // Make the constructors and destructor private
   Myevent();
   ~Myevent();
   Myevent(Myevent const&);
   Myevent& operator=(Myevent const&);
);

Myevent& Myevent::GetMyEvent()
{
   static Myevent theOnlyMyevent;
   return theOnlyMyevent;
}