g++ and null pointers
Falk Hueffner
hueffner@informatik.uni-tuebingen.de
Tue Aug 24 17:18:00 GMT 2004
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
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