C / C++ / MFC

HANDLE hMutex;
hMutex = CreateMutex(NULL,TRUE,TEXT("vision client"));
if(hMutex == INVALID_HANDLE_VALUE)
{
    AfxMessageBox("Unable to create Mutex");

}
else
{

    if(GetLastError()==ERROR_ALREADY_EXISTS)
    {
         HANDLE proc_h = GetCurrentProcess();
         AfxMessageBox("Application is already Opened !!!");
         _exit(0);
    }
}

while ((DWORD)lpHeader < (DWORD)(((LPSTR)lpStart) + size) && pt != NULL)

void DrawT2Outline(HDC hDC, LPTTPOLYGONHEADER lpHeader, DWORD size) 
{
    WORD                i;
    UINT                cTotal = 0; // Total points in a contour.
    LPTTPOLYGONHEADER   lpStart;    // the start of the buffer
    LPTTPOLYCURVE       lpCurve;    // the current curve of a contour
    LPPOINT             pt;         // the bezier buffer
    POINTFX             ptStart;    // The starting point of a curve
    DWORD               dwMaxPts = size/size of(POINTFX); // max possible pts.
    DWORD               dwBuffSize;

    dwBuffSize = dwMaxPts *     // Maximum possible # of contour points.
                 sizeof(POINT) * // sizeof buffer element
                 3;             // Worst case multiplier of one additional point
                                // of line expanding to three points of a bezier

   lpStart = lpHeader;
   pt = (LPPOINT)malloc( dwBuffSize );

    // Loop until we have processed the entire buffer of contours.
    // The buffer may contain one or more contours that begin with
    // a TTPOLYGONHEADER. We have them all when we the end of the buffer.
    while ((DWORD)lpHeader < (DWORD)(((LPSTR)lpStart) + size) && pt != NULL)

#include <iostream>
#include <string>
using namespace std;
 
class Person
{
private: 
    string name;
 
public:
    Person(string s)
    {
        name = s;
    }

    Person()
    {
        name = "";
    }

    void SayHello()
    {
        cout << "Hello, my name is " << name << "!" << endl;
    }
};
  
void Swap(Person *& a, Person *& b)
{
    Person *temp;
    temp = a;
    a = b;
    b = temp;
}
 
int main()
{
    Person *p1 = new Person("Alice");
    Person *p2 = new Person("Bob");
 
    cout << "Before swapping:" << endl;
    p1->SayHello();
    p2->SayHello();

    cout << endl << "Memory address of *p1:" << p1 << endl;
    cout << "Memory address of *p2:" << p2 << endl;
 
    Swap(p1, p2);

    cout << endl << "After swapping:" << endl;
    p1->SayHello();
    p2->SayHello();

    cout << endl << "Memory address of *p1:" << p1 << endl;
    cout << "Memory address of *p2:" << p2 << endl;
 
    delete p1;
    delete p2;
    return 0;
}

void Swap((Person *) &a, (Person *) &b)