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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: do { quit; } else { }
Date: Tue, 13 May 2025 18:15:17 -0700
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James Kuyper <jameskuyper@alumni.caltech.edu> writes:

> On 5/13/25 05:40, David Brown wrote:
>
>> On 12/05/2025 22:25, Keith Thompson wrote:
>
> ...
>
>>> I think that a lot of C programmers misunderstand what "compatible
>>> types" means.  Many seem to think that two types are compatible if
>>> they have the same representation and can be assigned without a cast.
>>
>> Yes.  Basically, most C programmers are not particularly aware of the
>> technical definitions of some of the terms in C standards where they
>> differ from common usage.  The word "compatible" in English means that
>> the things in question can work together or fit together.
>
> That's pretty much what it means in C. Two C types are compatible
> in C if the C standard *guarantees* that they can work together -
> that you can use the types interchangeably.  [...]

This description isn't exactly right, because the relationship of
being compatible is not an equivalence relation.  It is possible
that given types A, B, and C, A is compatible with B, and B is
compatible with C, but A is not compatible with C.