NULL==0?

[Clark S. Cox III]

Warning, error...depends on the compiler switch.

Conforming, non-conforming ... depends on the compiler switch. If it's a
warning, then the compiler is conforming. If it is an error (that causes
the compiler to reject the code) then the compiler is non-conforming.

I'll reiterate. Any compiler that rejects either of the following
programs is non-conforming:

#include <cstdlib>

int main()
{
int i = NULL;
return NULL;
}

//End program 1

#include <cstdlib>

int main()
{
int i = NULL + 5; //"warning: NULL used in arithmetic"
return NULL;
}