On Fri, 05 Jul 2013 10:17:02 +0100, Jonathan M Davis <jmdavisp...@gmx.com>
wrote:
On Friday, July 05, 2013 11:01:17 TommiT wrote:
On Thursday, 4 July 2013 at 19:15:09 UTC, Dmitry Olshansky wrote:
> 04-Jul-2013 19:00, Regan Heath пишет:
>> In fact, you can generalise further.
>>
>> The meaning of if(x) is "compare the value of x with 0" (in C,
>> C++, .. ).
>>
>> The value of x for a pointer is the address to which it points.
>> The value of x for a class reference is the address of the
>> class to
>> which it refers.
>>
>> If D's arrays are reference types,
>
> They are not. It's a half-reference no wonder it has a bit of
> schizophrenia now and then.
What do you mean by D's dynamic arrays being half-reference
types? And what kind of "schizophrenia" do exhibit?
Okay. Take this function.
void foo(T)(T bar)
{
bar.mutateMe();
}
If T is a reference type, then the argument passed to foo will be
mutated. If
T is a value type, it won't be. But with arrays, it depends. If you alter
bar's length in any way, it won't have any effect on the array that you
passed
to foo. However, if you alter any of bar's elements, then it _will_
alter the
array that was passed in. So, arrays are sort of a half-reference type
rather
than a reference type or a value type.
I think it is simpler to think of arrays as a struct with 2 members (ptr
and length) and this struct is/as a value type. Then it all simply makes
sense.
R
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