Re: [Boost-users] shared_ptr failure with undefined type (msvc)

15 Feb 2011


      AMDG

On 2/15/2011 9:35 AM, Gennadiy Rozental wrote:
...
I came to expect shared_ptr to handle undefined type, but here I got a test case
(simplified from my use case) where it's actually breaks under msvc and works
under gcc:
#include "boost/shared_ptr.hpp"
class UndefinedType;
//// base class for template
class FooBase{
public:
     virtual ~FooBase();
virtual void fff();
};
template<typename T>
class Foo: public FooBase {
public:
     virtual void fff()
     {
         // any virtual implementations seen are [have to be able to be]
instantiated. This fails unless T is visible.
         x.reset(x.get());
     }
private:
     boost::shared_ptr<T>  x;
};
//// now use Foo as a field in a class
class User {
     Foo<UndefinedType>  y;
};
It fails with:
...\boost-1.39\boost/checked_delete.hpp(32) : error C2027: use of undefined type
'UndefinedType'
Is this expected to compile? Is this MSVC issue?
Creating a shared_ptr from a raw pointer requires
a complete type, unless you pass a deleter.
MSVC must be instantiating Foo::fff sooner than
gcc is.

In Christ,
Steven Watanabe