[oolua] Re: shared_ptr question
- From: "Liam Devine" <liamdevine@xxxxxxxxx>
- To: oolua@xxxxxxxxxxxxx
- Date: Mon, 27 Jan 2014 17:00:47 -0000
On 27 Jan 2014, at 15:23, SteelRat wrote:
> Hi, Liam, i have a third party library so i can't change source.
It would be nice if I could see the source as your example makes no sense to
me. For example the constructor of A is private and not available in the
derived class B.
> There are all objects used with shared_ptr, NO raw pointers at all.
> It looks like this:
>
> class A
> {
> public:
> typedef std::shared_ptr<A> APtr;
> static APtr Create();
>
> private:
> A();
> ~A();
> };
>
> I have a problem to access "get" method of APtr.
Could you explain why you need to expose or use the get method in Lua?
>
> typedef A::APtr AAPtr;
>
> OOLUA_PROXY( AAPtr )
> OOLUA_TAGS(Shared, No_public_constructors)
> // OOLUA_MFUNC(get) // proxy class of A is not declared yet
> OOLUA_PROXY_END
>
This is a mistake which is probably due to the lack of documentation at the
moment. You do not create a proxy for shared pointers only the underlying types.
Also see [1] and [2] about the Shared tag.
>
> OOLUA_PROXY( A )
> OOLUA_TAGS(No_public_constructors)
> OOLUA_SFUNC(Create)
> OOLUA_PROXY_END
>
>
> And if i'm switching order of proxy declaration (A before APtr), there are
> error with "Create" method. There no docs on OOLua_shared_ptr yet, so may be
> i'm just doing something wrong?
> Now i'm using external function to get object, but i don't like it:
>
> int getSharedA(lua_State *L)
> {
> A::Ptr* obj;
> if (OOLUA::pull(L, obj))
> {
> OOLUA::push(L, obj->get());
> return 1;
> }
> return 0;
> }
>
>
>
>
> And second trouble, here is another class derived from A:
>
> class B: public A
> {
> public:
> typedef std::shared_ptr<B> BPtr;
>
> void DoSomething(A::APtr obj);
> static BPtr Create();
>
> };
>
> typedef B::BPtr BBPtr;
>
> OOLUA_PROXY( BBPtr)
> OOLUA_TAGS(Shared, No_public_constructors)
> OOLUA_PROXY_END
>
> OOLUA_PROXY( B, A )
> OOLUA_TAGS(No_public_constructors)
> OOLUA_SFUNC(Create)
> OOLUA_MFUNC(DoSomething)
> OOLUA_PROXY_END
>
> Lua code:
> varX = B.Create();
> varB = B.Create();
> varB:DoSomething(varX)
>
> Calling of DoSomthing causes error:
> "tried to pull type APtr_const which is not the type or a base of the
> type on the stack"
> In C++ it ( bPtr->DoSomething(xPtr) ) works, but BBPtr is not derived from
> AAPtr... What can i do with this?
>
That is how C++'s shared_ptr is defined. shared_ptr<B> is not related to
shared_ptr<A>, they are two separate types.
> Sorry for schematic example, but full working code is too big.
> Thank you.
>
Regardless, I need to see code that will at least compile and show what you are
trying to do. If you provide that I will be more than happy to explain where
you have gone wrong and provide a working example of your situation, if I can.
[1]
https://bitbucket.org/liamdevine/oolua/src/68cf0c0ec913cbe019d54fb33ab53d8f18cb06d6/include/proxy_tags.h?at=shared_ptr#cl-115
[2]
https://bitbucket.org/liamdevine/oolua/src/68cf0c0ec913cbe019d54fb33ab53d8f18cb06d6/include/oolua_config.h?at=shared_ptr#cl-277
--
Liam
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