array[-1] -- permitted?

[Chip Salzenberg]

According to news at ism780c.isc.com:
>But consider what might have happened had dpANS mandated that the compution
>of a pointer to x[-1] be a valid operation.

Okay, let's imagine:  X3J11 says that x[-1] must be valid.
	       then:  int must be 32 bits.
	       then:  address space must be linear.
	       etc. until only the SPARC is conforming.  (no smileys here)

Each time you make a "beneficial" restriction, you're condemning present
users of real, useful computers to the purgatory of enforced non-
conformance.  I don't think anyone really wants X3J11 to make decisions
about which hardware will be permitted to run C programs.

In addition, it should be observed that on this issue, X3J11 stuck to its
charter and codified existing practice.
-- 
Chip Salzenberg                <chip at ateng.uu.net> or <uunet!ateng!chip>
A T Engineering                My employer may or may not agree with me.
	  The urgent leaves no time for the important.