From: daniel.kruegler@googlemail.com   
      
   On 2011-11-08 09:06, Carlos Moreno wrote:   
   > Still, it seems quite shocking that the standard would not   
   > explicitly say something about accessing any member through   
   > dereferencing a NULL pointer. Or, for that matter, simply   
   > stating something about dereferencing a null pointer. I   
   > mean, for example, what would be the wording that states   
   > that the following is undefined behaviour:   
   >   
   > int * p = NULL;   
   > int a = *p;   
      
   This follows from normative statements from two sub-clauses in the standard:   
      
   a) [basic.lval] p1:   
      
   "   
   — An lvalue [..] designates a function or an object.   
   [..]   
   — An xvalue (an “eXpiring” value) also refers to an object,   
   [..]   
   — A glvalue (“generalized” lvalue) is an lvalue or an xvalue.   
   "   
      
   This defines an lvalue/gvalue as designating/referencing a function or   
   object.   
      
   b) [conv.lval] p1:   
      
   "A glvalue (3.10) of a non-function, non-array type T can be converted   
   to a prvalue. [..] If the object to which the glvalue refers is not   
   an object of type T and is not an object of a type derived from T, or if   
   the object is uninitialized, a program that necessitates this conversion   
   has undefined behavior."   
      
   This makes an lvalue-to-rvalue conversion defined, if (and only if) the   
   converted (g)lvalue refers to an initialized object.   
      
   > How would that wording (which I'm sure there has to be some   
   > *explicit* statement about the undefined-behaviour-ness of the   
   > above) not be general enough to cover the use of a NULL pointer   
   > to invoke a method on the pointed (inexistent) object as well??   
      
   Your example and above quoted normative statements don't help much in   
   the originally discussed example, where no lvalue-to-rvalue conversion   
   is involved.   
      
   HTH & Greetings from Bremen,   
      
   Daniel Krügler   
      
      
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