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From: Ben Bacarisse <ben@bsb.me.uk>
Newsgroups: comp.lang.c
Subject: Re: how cast works?
Date: Mon, 12 Aug 2024 16:57:24 +0100
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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
> [...]
>> Furthermore, there are cases where having to do a conversion from
>> one type to the same type has semantic consequences, even though
>> the types are the same.
>
> What are these cases?

The case that comes to mind is where the result of a floating point
expression is represented with more precision than the type can hold
when stored.

6.3.1.8 p2:
  The values of floating operands and of the results of floating
  expressions may be represented in greater range and precision than
  that required by the type; the types are not changed thereby.[63]

The footnote explains that the implicit conversion done on assignment
will change the value even though the types may be the same:

[63] The cast and assignment operators are still required to remove
     extra range and precision.

-- 
Ben.