On 29.04.2012 10:42, Jonathan M Davis wrote:
On Sunday, April 29, 2012 09:53:15 Dmitry Olshansky wrote:
On 29.04.2012 4:31, Jonathan M Davis wrote:
For better or worse, the solution for smart pointers in D would be to use
opDispatch,
*cough* alias this *cough*
That's not necessarily a good idea, depending on how it's used. You want to
avoid having the smart pointer implicitly convert to what it holds such that a
reference to it leaks. If you're dealing with a pointer to a struct, and alias
this aliases to the struct (rather than the pointer), then you're okay. But if
you're dealing with a class, you don't have that option. So, alias this ends
up leaking a reference to the class, which defeats the purpose of the smart
pointer. You have the same problem if alias this aliases to the pointer rather
than what's pointed to.
Point taken.
But regardless of whether you use alias this or opDispatch, you have the same
problem with regards to ->. In C++, . would be used to call the smart
pointer's functions, and -> would be used to call functions on the object
pointed to. In D, the two aren't distinguished - both use . - so you can't
have any functions on the type pointed to which conflict with the smart
pointer's functions, or you won't be able to call them (unless another way to
call them is provided somehow). So, it's definitely something that C++ does
better with as far as that goes.
So you just need not to have any _member_ functions on smart pointer?
Just use free functions that take SmartPointer!T. UFCS may also lend a
hand if T and SmartPointer do not have ambiguous funcs.
--
Dmitry Olshansky
