29 May
2003
29 May
'03
7:42 a.m.
It was thus said that the Great Patrick Finnegan once stated:
On Thu, 29 May 2003, Brian Hechinger wrote:
No, they don't have to be the same size; I think I recall that char * on
certain PDPs were slightly larger than say, an int * (because pointers only
pointed to word boundaries, yet you could pack several characters per word
so extra storage was needed to store the offset into a word for a char *).
And don't forget the whole mess with near and far pointers in the DOS world
(technically those were extentions but ... ).
Given the following declaration:
void *vp1;
void *vp2;
char *cp1;
char *cp2;
int *ip;
The following should hold true:
vp1 = cp1;
cp2 = vp1;
assert(cp1 == cp2); /* should be fine */
While the following may or may not work:
vp1 = cp1;
ip = vp1;
vp2 = ip;
cp2 = vp2;
assert(cp1 == cp2) /* may or may not hold */
-spc (Don't have the C Standard handy ... )
IMHO that's *always* a good thing. it has
really opened my eyes to the fact
that your average opensource coder has been so coddled by the whole gcc/x86
platform that they have really started to make stupid mistakes and even
stupider assumptions about things. the most common assumption is that a
void pointer and an int pointer is the same size. which just happens to be
Do you mean void * and int (not a pointer)? All pointers should be the
same size... (Sorry, I'm being pedantic.)