From: flaps@dgp.toronto.edu   
      
   I liked the "Saber C" C interpreter a few decades ago.  It had what I think   
   you are calling "safe pointers".   
      
   They had a paper at Usenix in I think the very-late 1980s, but in a   
   nutshell, every pointer value contained three addresses: the actual   
   address value, the lowest you were allowed to go with that pointer   
   value, and the highest you were allowed to go.   
   [Worked great, but it was an interpreter. -John]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)