[osg-users] Vec3Array instantiation

[Christian Buchner]

the osg::ref_ptr<> could be wrapped into a smart pointer, right? But what's
the point ;)

2016-04-07 10:33 GMT+02:00 Sebastian Messerschmidt <
sebastian.messerschmidt at gmx.de>:

> Hi Vincent,
>
>> Hello
>>
>> I'm trying to use osg:Vec3Array with a c++11 smart pointer instead of osg
>> smart pointer. I aim to join two APIs: osg and another one using C++11
>> smart pointer. Apparently, this is a destructor problem: ~TemplateArray<>()
>> is private, so an explicit delete doesn't work. I have test many cases to
>> understand the problem.
>>
>>
>> Code:
>> osg::Vec3Array * test = new osg::Vec3Array();
>> delete test; // error here
>>
>>
>>
>>
>> Code:
>> std::shared_ptr<osg::Vec3Array> test2(new osg::Vec3Array()); // error due
>> to pointer releasing
>>
>>
>>
>>
>> Code:
>> osg::Vec3Array test; // not work
>>
>>
>>
>>
>> Code:
>> osg::ref_ptr<osg::Vec3Array> test3 = new osg::Vec3Array(); // this work
>> fine.
>>
>>
>>
>> So there are few solutions to use the Vec3Array: use osg smart pointer.
>> What is the reason the destructor is protected even through the method is
>> empty? Maybe to force developers to use smart pointers but I'm constrained
>> to use c++11 smart pointer due to the second api. I think the only way, is
>> to create a C++11 smart pointer templated by osg smart pointer or a class
>> which contains the osg smart pointer.
>>
> First of all, the osg will manage the array fine when you keep it in a
> drawable, so there should no need to use your own management. If you need
> to hold it outside, simply use the ref_ptr. the ref_ptr is basically an
> smart-pointer for osg::Object derived objects.
> The reason the destructor is private is to prevent stack-instances of the
> type and to disallow use patterns like yours.
> If i remember correctly there was some guide on this in the wiki/trac.
>
>
> Do you have an idea to use C+11 smart pointer instead of osg one?
>
> Simply don't. It would not solve a single problem and would create
> pitfalls.
> Use the osg::ref_ptr if you need to keep an object (it acts as a "shared
> ptr"). If you need a week smart ptr you can use observer pointer.
>
>
> Cheers
> Sebastian
>
>
>
>> Thank you!
>>
>> Cheers,
>> Vincent
>>
>> ------------------
>> Read this topic online here:
>> http://forum.openscenegraph.org/viewtopic.php?p=66760#66760
>>
>>
>>
>>
>>
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>
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