[Caml-list] Re: Semantics of physical equality

[Jed Davis <jdev@panix.com>]

Michal Moskal <malekith@pld-linux.org> writes:

> On Fri, Feb 27, 2004 at 05:16:06PM -0600, Kevin S. Millikin wrote:
>> In the current problem, it can save me a great
>> deal of effort involved in generating temporary identifiers that are
>> guaranteed to be unique, and in wrapping library data structures that I
>> am unwilling to change in order merely to tag them.
>
> type t = V of int ref
>
> let t1 = V (ref 0)
> let t2 = V (ref 0)
>
> In this case you can assume t1 != t2. If it is not a sum type, but
> record type, you can use record with at least one mutable field.

Hm:

type t = unit ref
let t1 : t = ref ()
let t2 : t = ref ()
let mt : _ -> t = ref


-- 
[Jed Davis]              A098 903E 9B9A DEF4 168F  AA09 BF07 807E F336 59F9
 <jdev@panix.com>                                               0xF33659F9
  "But life wasn't yes-no, on-off.  Life was shades of gray, and rainbows
   not in the order of the spectrum." -- L. E. Modesitt, Jr., _Adiamante_

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