bug 348748 make NS_*_CAST always use C++-style casts (in preparation for

removing the macros altogether)
r=bsmedberg sr=dbaron

xpcom/base/nscore.h

@@ -423,14 +423,6 @@ typedef PRUint32 nsrefcnt;
   #define NS_SPECIALIZE_TEMPLATE
 #endif
 
-/* unix and beos now determine this automatically */
-#if ! defined XP_UNIX && ! defined XP_BEOS && !defined(XP_OS2)
-#ifndef HAVE_CPP_NEW_CASTS
-#define HAVE_CPP_NEW_CASTS 1 /* we'll be optimistic. */
-#endif
-#endif
-
-#if defined(HAVE_CPP_NEW_CASTS)
 #define NS_STATIC_CAST(__type, __ptr)      static_cast< __type >(__ptr)
 #define NS_CONST_CAST(__type, __ptr)       const_cast< __type >(__ptr)
 
@@ -438,45 +430,6 @@ typedef PRUint32 nsrefcnt;
 #define NS_REINTERPRET_NONPOINTER_CAST(__type, __obj) reinterpret_cast< __type >(__obj)
 #define NS_REINTERPRET_CAST(__type, __expr)           reinterpret_cast< __type >(__expr)
 
-#else
-#define NS_STATIC_CAST(__type, __ptr)      ((__type)(__ptr))
-#define NS_CONST_CAST(__type, __ptr)       ((__type)(__ptr))
-
-#define NS_REINTERPRET_POINTER_CAST(__type, __ptr)     ((__type)((void*)(__ptr)))
-#define NS_REINTERPRET_NONPOINTER_CAST(__type, __obj)  ((__type)(__obj))
-
-  /* Note: the following is only appropriate for pointers. */
-#define NS_REINTERPRET_CAST(__type, __expr)            NS_REINTERPRET_POINTER_CAST(__type, __expr)
-  /*
-    Why cast to a |void*| first?  Well, when old-style casting from
-    a pointer to a base to a pointer to a derived class, the cast will be
-    ambiguous if the source pointer type appears multiple times in the
-    destination, e.g.,
-    
-      class Base {};
-      class Derived : public Base, public Base {};
-      
-      void foo( Base* b )
-        {
-          ((Derived*)b)->some_derived_member ... // Error: Ambiguous, expand from which |Base|?
-        }
-
-    an old-style cast (like |static_cast|) will change the pointer, but
-    here, doesn't know how.  The cast to |void*| prevents it from thinking
-    it needs to expand the original pointer.
-
-    The cost is, |NS_REINTERPRET_CAST| is no longer appropriate for non-pointer
-    conversions.  Also, mis-applying |NS_REINTERPRET_CAST| to cast |this| to something
-    will still expand the pointer to the outer object in standards complying compilers.
-  */
-
-  /*
-    No sense in making an NS_DYNAMIC_CAST() macro: you can't duplicate
-    the semantics. So if you want to dynamic_cast, then just use it
-    "straight", no macro.
-  */
-#endif
- 
 /* 
  * Use these macros to do 64bit safe pointer conversions.
  */