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To: Eljay Love-Jensen <eljay@adobe.com>
Cc: gcc-help@gcc.gnu.org
Subject: Re: g++ and null pointers
References: <6.1.2.0.2.20040824053102.01e9b890@iplan-mn.corp.adobe.com>
From: Falk Hueffner <hueffner@informatik.uni-tuebingen.de>
Date: Tue, 24 Aug 2004 17:18:00 -0000
In-Reply-To: <6.1.2.0.2.20040824053102.01e9b890@iplan-mn.corp.adobe.com> (Eljay
 Love-Jensen's message of "Tue, 24 Aug 2004 05:47:46 -0500")
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Eljay Love-Jensen <eljay@adobe.com> writes:

> When I compile this test.cpp source...
>
> // g++ -Wno-long-long -pedantic -Wall -W -c test.cpp
> #define NULL __null
> int main()
> {
>      void* p;
>      p = 0;
>      p = 0u;
>      p = 0ul;
>      p = 0ull;
>      p = 0l;
>      p = 0ll;
>      p = false;
>      // silly...
>      p = -0;
>      p = -0u;
>      p = -0ul;
>      p = -0ull;
>      p = -0l;
>      p = -0ll;
>      p = -false;
>      // my druthers...
>      p = NULL;
>      return 0;
> }
>
> ...GCC is happy with all of these assignments.
>
> Are they all supposed (ISO 14882) to be legit?  Some of them surprised me.

The standard says that a null pointer constant is "[a]n integer
constant expression with the value 0", so these seem all OK.

-- 
	Falk