Re: Immediate doubles (up to 2^256) and rationals coming to Guile 3

[Arne Babenhauserheide <arne_bab@web.de>]

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Chris Vine <vine35792468@gmail.com> writes:

> On Sat, 08 Jun 2019 10:07:45 +0200
> Arne Babenhauserheide <arne_bab@web.de> wrote:
> [snip]
>> Wow, I didn’t know that you could do that.
>> 
>> However: "The details of that allocation are implementation-defined, and
>> it's undefined behavior to read from the member of the union that wasn't
>> most recently written." https://en.cppreference.com/w/cpp/language/union
>> 
>> Can you guarantee that this works?
>
> This is C and not C++ and the provision to which you refer does not
> apply.
>
> Reading from a member of a union other than the one last written to is
> implementation defined in C89/90, and defined in C99 (with Technical
> Corrigendum 3) and above

Thank you for the correction and explanation!

Best wishes,
Arne
-- 
Unpolitisch sein
heißt politisch sein
ohne es zu merken

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