On 07/06/2017 01:24 PM, FoxyBrown wrote:
> On Thursday, 6 July 2017 at 18:11:13 UTC, H. S. Teoh wrote:
>> On Thu, Jul 06, 2017 at 06:10:57PM +0000, FoxyBrown via Digitalmars-d
>> wrote:
>>> Create an auto pointer, handy in some cases and fits in the language
>>> as a natural generalization.
>>
>> What's an auto pointer?
>>
>>
>> T
>
> is it not obvious?
It wasn't obvious at all. :) (I even suspected C++'s std::auto_ptr but
dropped the thought.)
> auto p = &foo; // a pointer
> auto* p = &foo; // a double pointer to foo.
>
> When having the need to require a pointer to a pointer, it avoids having
> to specify the type in a verbose way.
>
> i.e., the second line above is not valid, but to do it we must either
> cast to void** or use typeof and such to get the correct type and make a
> pointer out of it. auto* simplifies all that.
Let's say foo is type Foo...
Staying with that example and assuming that p has type Foo**, what would
*p provide? We have the object (foo), we have the pointer to pointer
(p), but where does the pointer itself live? Only the programmer knows
where that intermediate pointer is. For example:
struct Foo {
}
void main() {
auto foo = Foo();
auto x = &foo; // A local variable here
auto p = &x;
}
It seems to work cleanly to me. If you have something else in mind
please show the troubling line with complete code. :)
Ali
