[comp.lang.c++] Bug: temporary object in && expression

mvm@jedi.harris-atd.com (Matt Mahoney) (08/27/90)

Does anyone know of a C++ compiler that handles code like:

	String s; 
	if (s == "something" || s == "something else")  // error

Turbo C++ 1.0, Zortech 2.1, and Sun C++ 2.0 (a cfront port) all fail
to handle temporary objects with destructors in && or || expressions.
Here is a more complete example:

// cfront: Sorry, not implemented...
// Turbo C++: Calls constructor once, destructor 3 times
// Zortech: Calls constructor once, destructor twice

struct X
{
  X(int x) {cout << "X(" << x << ")\n";}
  ~X() {cout << "~X()\n";} 
};
int f(X x) {return 0;}

main()
{
  1 && f(3);  // Calls X(3) and ~X()
  0 && f(3);  // bug: calls destructor only
  1 || f(3);  // bug: calls destructor only
}

---------------------------------------------------
Matt Mahoney, (407) 727-5431, mvm@epg.harris.com, mvm@trantor.harris-atd.com
#include <disclaimer.h>  // <disclaimer.hpp> in Zortech
			 // <iodisclaimer.h> in Turbo