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From: osmium on 19 Dec 2009 11:40
"Francis Glassborow" wrote:

> Antoon wrote:

>> The size of a pointer is in no way related to the size of the object it
>> points to.
>>
> That is a slight overstatement. With some limitations the size of a
> pointer can (on some implementations is) different depending on the type.
> All pointers to class types must be the same size and (I think) layout.
> But pointers to enums can depend on the underlying type and pointers to
> builtin types can vary in size.

If x is a variable and y is a different variable, and given x, you can not
determine y, or, given y you can not determine x, then the two variable are
said to be unrelated. I think that is the meaning Antoon had in mind when
he said they were unrelated. I found it a perfectly adequate explanation of
the situation and needed no further "clarification".


From: Keith Thompson on 19 Dec 2009 12:24
"osmium" <r124c4u102(a)comcast.net> writes:
> "Francis Glassborow" wrote:
>> Antoon wrote:
>>> The size of a pointer is in no way related to the size of the object it
>>> points to.
>>>
>> That is a slight overstatement. With some limitations the size of a
>> pointer can (on some implementations is) different depending on the type.
>> All pointers to class types must be the same size and (I think) layout.
>> But pointers to enums can depend on the underlying type and pointers to
>> builtin types can vary in size.
>
> If x is a variable and y is a different variable, and given x, you can not
> determine y, or, given y you can not determine x, then the two variable are
> said to be unrelated. I think that is the meaning Antoon had in mind when
> he said they were unrelated. I found it a perfectly adequate explanation of
> the situation and needed no further "clarification".

If you happen to know that y > x, then you can't determine the
value of y given x or vice versa, but it would be incorrect to say
that their values are "in no way related". The relationship is a
relatively weak one, but it's there.

I thought about raising the same point Francis did, though I
probably would have said that it's a *very* slight overstatement.
There can be a relationship between the size of a pointer and the
size of the object it points to, but it's not a relationship that
you can or should ever depend on.

The point (and I think it's a minor one) is just that
Antoon's phrase "in no way related" was slightly exaggerated.

--
Keith Thompson (The_Other_Keith) kst-u(a)mib.org <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
From: maigre_dragon on 21 Dec 2009 08:19
Thank you! I think what I need it. I need to think MemoryMap<T*> that is
different goodly with MemoryMap<T> .

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