Will there be memory leak ?????

[Vijay]

Hi ,
I have created a program using CMapStrintToPtr where I would be
mapping
structure ptr to map string. This is just a sample program which I
thought
to avoid linear search in link list since my actual data is so huge.

I created a Windows console program. Since I am assigning a memory
block to
the structure node and I am not freeing it anyway in the program. Will
there be memory leak. Is it necessary to free the memory in my code.
If I want to free
how should I free it. I am thinking of get cmP.GetCount then get 1st
strcuture ptr by cmP.GetStartPos ition then go through each by
cmP.GetNextAsso c and free
each structure ptr we get. Is this correct. Please tell more.

My code is

#include <iostream.h>
#include <afxcoll.h>
#include <conio.h>

CMapStringToPtr cmP;

struct vj
{
int type;
char name_type[100];
};

void mapFunction(cha r *mapStr, int typ, char *typeName)
{

struct vj *vijay;
vijay = (struct vj *) malloc (sizeof (struct vj));
strcpy(vijay->name_type, typeName);
vijay->type = typ;

cmP.SetAt ( mapStr, vijay);
}

void main()
{

mapFunction("li ", 3, "line");
mapFunction("ls ", 4, "linestring ");
mapFunction("sh ", 5, "shape");

struct vj *temp;
cmP.Lookup ("sh", (void*&)temp);
cout<< temp->type <<" " << temp->name_type << endl;
getch();

}
Thanks vijay.

[Ivan Vecerina]

"Vijay" <sa****@yahoo.c om> wrote in message
news:7c******** *************** ***@posting.goo gle.com...

I have created a program using CMapStrintToPtr where I would be
mapping
structure ptr to map string. This is just a sample program which I
thought
to avoid linear search in link list since my actual data is so huge. CMapStringToPtr is not a standard C++ class. Most people here do
not know (or want to know) what it does.
I created a Windows console program. Since I am assigning a memory
block to
the structure node and I am not freeing it anyway in the program. Will
there be memory leak. Is it necessary to free the memory in my code. Yes, Yes.
If I want to free how should I free it.

Really, you should use better designed classes, such as those
available in the standard C++ library, that will save you from
doing manual memory management.
See below how leaner and cleaner your program gets -- not to mention
safer and more portable:

#include <iostream> //NB: iostream.h is non-standard.
#include <map>
#include <string>
//using namespace std; // put this to not repeat std:: below

struct vj // could eventually be replaced by a std::pair ...
{
int type;
std::string name_type;
vj(int t, std::string n) : type(t), name_type(n) {} //added
};

//nb: no mapFunction needed, the constructor replaces it

int main() // void main() is NOT allowed in standard C++
{
std::map< std::string, vj > cmP;

cmP["li"] = vj(3,"line");
cmP["ls"] = vj(4,"linestrin g");
cmP["sh"] = vj(5,"shape");

//NB: cmP.Lookup ("sh", (void*&)temp) --> was undefined behavior
vj& temp = cmP["sh"];
std::cout << temp.type <<" "<<temp.name_ty pe<<std::endl;

return 0;
}
I would recommend getting a real C++ book (e.g. "Accelerate d C++"),
and (or else) posting to a windows-specific forum when using
platform-specific libraries.

Ivan
--
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