🚀 go-pugleaf

In article <dewar.813699321@schonberg> dewar@cs.nyu.edu (Robert Dewar)
writes:

|>         char p[10], q[10];
|>         int r = &p[5] - &q[2];

|> this is plainly incorrect C, so this is not the kind of issue that arises
|> in bounds checking. THe problem is that pointers can be havily aliased 
|> in C, and I repeat my observation, without auxiliary data structures of som
|> e kind you can't tell if a pointer is a pointer to an integer or a pointer
|> to an element of an array, so you can't tell if it is valid to decrement it.

But there is nothing in the standard which prohibits the auxiliary
structure, and any operation which would normally result in a bounds
check error has undefined behavior, so a conforming C/C++
implementation with full bounds checking is possible.  In fact, I
believe that ObjectCenter actually sells such an implementation.
-- 
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