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From: Andrey Tarasevich <noone@noone.net>
Newsgroups: comp.lang.c
Subject: Re: Regarding assignment to struct
Date: Mon, 5 May 2025 01:29:47 -0700
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On Mon 5/5/2025 1:12 AM, Michael S wrote:
> 
> According to my understanding, you are wrong.
> Taking pointer of non-lvalue is UB, so anything compiler does is
> conforming.
> 

Er... What? What specifically do you mean by "taking pointers"?

The whole functionality of `[]` operator in C is based on pointers. This 
expression

   (a = b).a[5]

is already doing your "taking pointers of non-lvalue" (if I understood 
you correctly) as part of array-to-pointer conversion. And no, it is not UB.

This is not UB either

   struct S foo(void) { return (struct S) { 1, 2, 3 }; }
   ...
   int *p;
   p = &foo().a[2], printf("%d\n", *p);

So, what you are basing your "UB" claim on is not clear to me.

-- 
Best regards,
Andrey