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Again.
GCC is behaving according to the C Standard, which specifies that malloc(0) or calloc(0, x) return either NULL, or a unique pointer. This is implementation defined behaviour - the implementation must specify what behaviour it supports.
Your code is not checking the size of the block referenced by sz, sizeof(*sz). It is checking the size of the pointer, sizeof(sz). You are apparently running on a system with 64-bit pointers.
If malloc(x) or calloc(y, x) return a non-NULL pointer, you are guaranteed that it points to a memory area of at least x or x * y chars, respectively. In order to discover the exact area, you will need to call an implementation-specific API; the C Standard does not define an API to return the actual size of an allocated memory area.
Note that even if the result of malloc(0) or calloc(0, x) is a unique pointer, that pointer cannot be portably dereferenced, as it is guaranteed to reference only a zero-sized memory area.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
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Understood.
My point is asking for zero bytes of memory gets me an OK (not a NULL) whether I use calloc or malloc.
I have problems with that behavior.
I realize that it's saying I got what I wanted.
Checking for NULL is not a guaranteed successful approach.
Instead one should be checking for non-zero allocation parameters prior to calling malloc or calloc!
"A little time, a little trouble, your better day"
Badfinger
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Testing to see what actually happens is a good idea.
But never forget: "Implementation dependent" does not mean "The way gcc implements it" (or any other given compiler), even though gcc users often seems to think that way. Any other C compiler may think differently.
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I agree.
"A little time, a little trouble, your better day"
Badfinger
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The testing showed me that using calloc and malloc requires some extra checking for zero memory requests.
As a result, I am scanning my uses of it in my older code. I do not think I inadvertently allocated zero memory, I want to be sure. BTW malloc and calloc return NULL when memory requested is less than zero.
"A little time, a little trouble, your better day"
Badfinger
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Behavior for the first one is implementation defined[^].
Meanwhile, the second is just a weird way of saying null.
Am I missing something?
Mircea
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agree,
GNU GCC
BTW can you id the background in my photo. Hint Canada
"A little time, a little trouble, your better day"
Badfinger
modified 13-Dec-22 1:11am.
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jmaida wrote: GNU GCC
Not quite. malloc() is provided by libc. For most linux distributions, that will be provided by GNU libc, but it doesn't have to be.
Keep Calm and Carry On
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jmaida wrote: BTW can you id the background in my photo. Hint Canada
Not really: you are too big and skyline is too small. Looks like "city by the water" but that's not narrowing it much 
Mircea
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Behind is Detriot River and Canada @ Angstrom Park, part of Amherstburg, just north of Crystal Island.
"A little time, a little trouble, your better day"
Badfinger
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mwh, standards shmandereds. They both return null.
To err is human. Fortune favors the monsters.
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char* sz = (char*)(strchr("1",'0' + 1) - strchr("1",'0' + 1));
Now ask some C++ guru, how to make this constexpr.
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I'm wondering if it is a subversive campaign to create a SoapBox?
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
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Or are you just thin-skinned at _this_ moment?
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There's a much more simple answer.
I'm trying to get my Rep Numbers boosted.
I'm currently at 125.9K & I've heard that when I reach 126K (or greater) -- seems arbitrary but it's true -- that CP will be sending me a check for $1USD per point.
I'm quite excited.
I believe @chris-maunder hand delivers the check to your home, so I'll meet a Star too!!
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I have some really bad news for you ... 
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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I would be happy enough if I got a CP Coffee mug to make my co-worker envious  
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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I think any Protector who has never received a CP coffee mug should be sent one. ![Green Alien | [Alien]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/alien.gif) ![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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I second that  
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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I have too many. I could send you one maybe, but you're not in the US are you?
To err is human. Fortune favors the monsters.
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Nope, I am in Germany.
Thank you anyways
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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Actually it's Sean in a mankini. You'll need to talk to him about the cheque. It may be that you get the actual mankini instead.
cheers
Chris Maunder
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I figured folks have invested in popcorn suppliers. :popcorn:
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#Worldle #325 2/6 (100%)
🟩🟩⬜⬜⬜⬅️
🟩🟩🟩🟩🟩🎉
https://worldle.teuteuf.fr
"A little time, a little trouble, your better day"
Badfinger
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I typically keep a /notes folder under my professional work such that I can write down pertinent things that come up as the project progresses such as technical points from a phone conversation relevant to the completing the software project (what hardware driver ICs are being used for example)
It does a few things. It keeps me organized, and keeps my notes safely in source control. It also keeps things handy for other people I work with to go through.
It's very simple to do, and it has proven invaluable to me time and again.
To err is human. Fortune favors the monsters.
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