On 10/05/13 16:26, Julian Gonggrijp wrote:
Larry Evans wrote:
https://github.com/jgonggrijp/rich-typed-pointers [snip] If there were a templated owned_ptr CTOR:
template<typename Derived> owner_ptr (owner_ptr<Derived> && source) : pointer(source.pointer) { source.pointer = nullptr; }
wouldn't that eliminate the need for the make_dynamic templated function?
Just wondering. I haven't tried it, but I'd guess it would work because the ownd_ptr<Derived> could be constructed with the:
make<Derived>(t1,t2,...tn)
and then the templated owned_ptr CTOR would then convert that to the base class?
I agree this would be great, but unfortunately it appears it can't be done. owner_ptr<Derived> would have to friend-declare owner_ptr<Base>, I don't see why. AFAICT, you'd require *fewer* friend declarations, not more( you wouldn't need the:
template <class U1, class U2, class ... Us> friend owner_ptr<U1> make_dynamic (Us&& ...); the only friend needed would the existing: template <class U, class ... Us> friend owner_ptr<U> make (Us&& ...); that's because the proposed templated constructor would have the same access as the existing: owner_ptr (owner_ptr && source); CTOR, i.e. public. IOW, with the proposed templated CTOR, the following example code creating an owner_ptr<Base> should work, AFAICT: owner_ptr<Base> owner_baee ( make<Derived> ( DerivedInit0() , DerivedInit1() . . . DerivedInitN() ) ); Where DeriveInit0, DerivedInit1, ... DerivedInitN are the types of the args to the CTOR for Derived. Is there some reason why the above example code would *not* compile, given then proposed templated CTOR? [snip] -regards, Larry