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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: sizeof object got by dereferencing uniniitalized pointer
Date: Thu, 28 Nov 2019 16:37:46 -0800
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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:

> Thiago Adams <thiago.adams@gmail.com> writes:
> <cut>
>
>> Only when applied to variably types, sizeof is in runtime.
>>
>>   int n = 10;
>>
>>   int(*buf)[n] = malloc(sizeof(int) * n);
>
> Why would you not write
>
>    int (*buf)[n] = malloc(sizof *buf);
>
> ?

Perhaps because, technically speaking, the right-hand side here
has undefined behavior?