PRB: exit() Function Does Not Clean Up Nonstatic Objects

• The Microsoft C/C++ Compiler supplied with: - Microsoft C/C++ for MS-DOS, version 7.0 - Microsoft Visual C++ for Windows, versions 1.0, 1.5, 1.51, 1.52 - Microsoft Visual C++, 32-bit Edition, versions 1.0, 2.0, 2.1, 4.0,

       4.1, 4.2, 5.0
  

SUMMARY

When an application calls the exit(), _exit(), _cexit(), or _c_exit() functions, the destructors for any temporary or automatic objects that exist at the time of the call are not called. The text below provides a sample program to demonstrate this behavior.

MORE INFORMATION

An automatic object is an object that is defined in a function where the object is not declared to be "static." A temporary object is an object created by the compiler.

To destruct an automatic object before calling exit(), explicitly call the destructor for the object, as follows:

   myObject.myClass::~myClass();

Sample Code

  /* Compile options needed:  for 16-bit - /f /Od /Zi
   *                           for 32-bit - none
   */

   #include <iostream.h>
   #include <process.h>

   class myClass
   {
      int nVal;

   public:
      myClass();
      void View() {cout << nVal << "\n";};
      ~myClass();
   };

   myClass::myClass()
   {
      nVal = 99;
   }

   myClass::~myClass()
   {
      cout << "Destructor has been called\n";
   }

   void main(void)
   {
      myClass myObject;

      myObject.View();

   // Remove the comment from the next line to call the destructor
   // myObject.myClass::~myClass();

      exit(0);
   }