What's the right way to handle situations
where programs run out of memory?

Thanks in advance for every answer.
  Stefan Kuhlins

PS: Here are the "facts" and a little testprogram:

ARM r.12.5

If operator new() cannot allocate storage it will return 0.


WP r.3.6.3.1 [basic.stc.dynamic.allocation] (3, 4)

If an allocation function is unable to obtain an appropriate block of
storage, it may invoke the currently installed new_handler and/or
throw an exception of class alloc or a class derived from alloc.

If the allocation function returns the null pointer the result is
implementation defined.


WP r.5.3.4 [expr.new] (17)

The allocation function may indicate failure by throwing an `alloc'
exception.


I tested this with a little program (see below) and several compilers.
Caution: Compiled with Borland C++ 1.5 for OS/2 the program stops the
-------- whole system!

#include <iostream.h>
#include <new.h>
#include <stdlib.h>
#include <except.h>  // xalloc

void myhandler() {
  cerr << "My Handler" << endl;
  exit(1);
}

int main() {

// To be compatible with old programs:
// set_new_handler(0);

// Install your own handler and every system should have the same behavior:
// set_new_handler(myhandler);

// Handle the exception, if your compiler has exception handling
// and you know the name of the class thrown:
// try {

    for (;;) {
      if ((new double[10000])==0) {  // the old way
        cerr << "No memory!" << endl;
        return 1;
      }
      else
        cout << '.';
    }

// } catch(xalloc) {
//   cout << "Exception!" << endl;
// }

  return 0;
}