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From: fischer@iesd.auc.dk (Lars P. Fischer)
Newsgroups: comp.lang.c,comp.lang.misc
Subject: Re: C strongly typed?
Message-ID: <FISCHER.90Mar13222605@blue.iesd.auc.dk>
Date: 13 Mar 90 21:26:05 GMT
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	<1990Mar7.182230.5517@utzoo.uucp) <862@enea.se>
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In-reply-to: sommar@enea.se's message of 10 Mar 90 00:06:59 GMT

In article <862@enea.se> sommar@enea.se (Erland Sommarskog) writes:
>Well, apparently I am allowed to mix apples and oranges. If I have
>two types of data that both happens to be represented by integers,
>but have no logical connection what so ever I cannot apparently 
>express that in C. 

True. C has type synonyms, but you cannot introduce new types. It a
pain at times, but you learn to live with it. Note that this does
*not* mean that C is not strongly typed (it is). It means that there
are some type constructions mechanisms that are not available in C.

>And consequently I cannot take help from the
>compiler to catch inadvertent mixups in for instance procedure calls.

However:

   banach> cat te.c
   typedef enum { o1, o2 } orange ;
   typedef enum { a1, a2 } apple ;

   orange o;
   apple a;

   void main ()
   {
	   o = o1;
	   a = o;
   }

   banach> lint te.c
   te.c(10): warning: enumeration type clash, operator =
   banach>

Use lint, not Ada.

/Lars
--
Lars Fischer,  fischer@iesd.auc.dk   | Q: How does a project get to be one
CS Dept., Univ. of Aalborg, DENMARK. | year late?  A: One day at a time.