🚀 go-pugleaf

darcy@druid.uucp (D'Arcy J.M. Cain) writes:

>steve@taumet.com (Steve Clamage) writes:
>>That said, suppose we have a system where int and size_t are 16 bits,
>>but it is possible to allocate an object bigger than 64K.  A

>But isn't size_t guaranteed to be big enough to specify any object?  It
>is stated in a kind of roundabout way in the standard (you have to follow
>up sizeof) but I don't think there is any doubt that if an object can be
>larger than 64K then size_t must reflect this.

size_t is the type returned by the sizeof operator.  I believe you
must be able to apply sizeof to any object you can declare.  Suppose
ints and size_t are each 16 bits, and the compiler rejects any attempt
to declare an object greater than 64K:
	int big    [32767];	/* OK */
	int bigger [32769];	/* ERROR: too big */
This could be a conforming implementation.

Now suppose that the implementor wants to allow access to extra
memory when it is available, and allows calls like
	calloc(1024, 100)	/* 100K allocation */
for example.  I don't think this violates any rules.  You can't
use sizeof to find the size of a dynamically allocated region.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com
Vice Chair, ANSI C++ Committee, X3J16