Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!rutgers!att!dptg!ulysses!andante!alice!bs
From: bs@alice.UUCP (Bjarne Stroustrup)
Newsgroups: comp.lang.c++
Subject: Re: the secret bang
Summary: not a feature but a ...
Message-ID: <10026@alice.UUCP>
Date: 17 Oct 89 01:21:53 GMT
References: <1167@osc.COM>
Organization: AT&T Bell Laboratories, Murray Hill NJ
Lines: 41




osc.com (henry strickland 415-325-2300) of the techwood toaster
pastry users group, georgia tech, Object-Sciences Corp (God's own startup)
writes:

// Curious to AT&T cfront2.0 is the undocumented postfix-bang operator.
// It can only be used in type declarations, to mean the same thing as
// the prefix-star operator or the postfix-empty-brackets operator.

Yuck. I thought we finally had gotten it out!

// Any conjectures why the secret bang is there?  Wasn't postfix "!" a
// dereference operator in BCPL? 

Infix ! is the BCPL subscripting operator. What you saw was a supposedly
removed fragment of an experiment to provide a representation for C and
C++ that could be written using the ISO 646 character set standard without
the use of national characters as operators.


FYI, ASCII is the US national version of ISO646 (assuming I got the number
right) and it has the curious feature that the 6 character codes designated
for alphabetic characters have been used as operators. Most European
languages have more letters in the alphabet than English and use those
character codes for those ``extra'' letters. In particular, if
I wants to write in my native language (Danish) I cannot also use the
symbols []{}\| when using a device with a ISO646 character set.


Someone from the Danish ISO committee and the Danish Unix Users' Group
me to find a representation that allowd them to write C++ in Danish and
other European languages. We havene't had much luck with the proposal
(you can find it in one of the EUUG newsletters from this year), but
! was the subscript operator, the replacement for [].

// P.S.  Let's no one argue about its merit as a feature of C++.  It's
//       not, and will never be, and should never be.  It's just curious!

Agreed.