Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!uw-beaver!apollo!mrst!sdti!mjy
From: mjy@sdti.UUCP (Michael J. Young)
Newsgroups: comp.lang.c
Subject: Re: typedef laxity
Message-ID: <251@sdti.UUCP>
Date: 18 Apr 88 14:04:00 GMT
References: <1070@maynard.BSW.COM> <542@picuxa.UUCP> <1071@maynard.BSW.COM> <4399@ihlpf.ATT.COM>
Reply-To: mjy@sdti.UUCP (0000-Michael J. Young)
Organization: Software Development Technologies, Sudbury MA
Lines: 33

In article <4399@ihlpf.ATT.COM> nevin1@ihlpf.UUCP (00704a-Liber,N.J.) writes:
>Here is one that I see a lot among beginning C programmers:
>
>	typedef	char *	string;
>
>If I have the following declaration:
>
>	string	foo;
>
>I really don't want
>
>	foo = "bar";
>
>to be an error or even a warning from lint.

Actually, this probably isn't a good example.  A more likely implementation
of strong typing of typedefs would treat the base type as compatible with
a new type derived from it.  For example, in Modula-2 (taken directly from
Wirth's book):
	TYPE A = ARRAY [0..99] OF CHAR;
	     B = ARRAY [0..99] OF CHAR;
	     C = A;
Variables of type C are compatible with those of type A, but A and B are
incompatible.  Similarly, variables of type A are compatible with those of
type ARRAY [0..99] of CHAR.

Using this model, type string should be compatible with string literals, which
in this context are just char *.
-- 
Mike Young - Software Development Technologies, Inc., Sudbury MA 01776
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