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In article <9603251201.AA24987@lts.sel.alcatel.de> James Kanze 
US/ESC 60/3/141 #40763 <kanze@lts.sel.alcatel.de> writes:

  In article <4j1tm6$bmu@senator-bedfellow.MIT.EDU> jgealow@mtl.mit.edu
  (Jeffrey C. Gealow) writes:

  |>   The technique described in the ARM 3.4 annotation cannot be applied to
  |>   const objects since the values of the objects may not be changed.

  No.  Const has nothing to do with the question, since objects only
  become const after construction.

I don't understand James Kanze's comment.  Consider:

  // file nifty_library.h:
  //

  class X {
  public:
    int i;
    X() : i(10) {};
  };

  extern const X obj;
 
  class nifty_counter {
    static nifty_count;
  public:
    nifty_counter() {
      if (nifty_count++ == 0) {
        obj.i = 5;
      }
    }
  };


  // file nifty_library.cc:
  //

  #include "nifty_library.h"

  const X obj;

The intent of the statement obj.i = 5 in nifty_counter::nifty_counter() 
is to "initialize" obj.  But formally, obj is initialized by the 
default constructor for class X.

% CC -c nifty_library.cc
"nifty_library.h", line 17: Error: The left operand cannot be assigned to.
1 Error(s) detected.
% CC -Dconst="" -c nifty_library.cc

Perhaps the problem may be circumvented by casting away const: ((X) obj).i = 5;

   I believe that the intent of the current draft is that rule in ARM 3.4
   hold only for uses invoked directly or indirectly from main, but not
   for uses which result from the construction of other static objects.

Perhaps the intent should be clarified in the text of the draft.

Jeff


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