Re: std::auto_ptr exception

From:
"Vladimir Grigoriev" <vlad.moscow@mail.ru>
Newsgroups:
microsoft.public.vc.language
Date:
Wed, 4 Mar 2009 16:58:07 +0300
Message-ID:
<#SQsMFNnJHA.2560@TK2MSFTNGP05.phx.gbl>
Thank, Igor.
Using void * allows the following code

#include "stdafx.h"

template <typename T>

class A

{

public:

    A( void * initValue ): vp( initValue ) {}

    A( const A & rhs ): vp( rhs.vp ) {}

    ~A() { delete ( T *)vp; }

private:

    void *vp;

};

class B {};

int _tmain(int argc, _TCHAR* argv[])

{

    B *bp = new B;

    {

        A<int> a = bp;

    }

    return 0;

}

Vladimir Grigoriev

"Igor Tandetnik" <itandetnik@mvps.org> wrote in message
news:%23xMk%23qMnJHA.3876@TK2MSFTNGP02.phx.gbl...

"Vladimir Grigoriev" <vlad.moscow@mail.ru> wrote in message
news:uLNWYQMnJHA.5228@TK2MSFTNGP02.phx.gbl

I tried the following example by using Visual C++ 2005 EE

#include "stdafx.h"
#include <memory>
std::auto_ptr<int> source()
{
   return new int( 10 );
}


This shouldn't compile - there is no implicit conversion from int* to
std::auto_ptr<int>. You have to write

return std::auto_ptr<int>(new int(10));

The run-time exception (due to double destruction) is just a consequence
of allowing an incorrect program to compile in the first place. See

http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=101842

--
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   Igor Tandetnik

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