auto_ptr in managed code

[Bill Burris]

How do I use auto_ptr in managed C++?

Here is my existing code:

namespace Alta
{
public __gc class CMDAQ
{
public:
CMDAQ();
~CMDAQ();
private:
CDAQControl* itsDAQControl;
};
}

namespace Alta
{
CMDAQ::CMDAQ( )
{
itsDAQControl = new CDAQControl();
}

CMDAQ::~CMDAQ()
{
delete itsDAQControl;
}
}

If I change this code to the following, I get "error C3633: cannot define
itsDAQControl as a member of managed Alta::CMDAQ"

namespace Alta
{
public __gc class CMDAQ
{
public:
CMDAQ();
~CMDAQ();
private:
std::auto_ptr< CDAQControl > itsDAQControl;
};
}

namespace Alta
{
CMDAQ::CMDAQ( )
{
std::auto_ptr< CDAQControl > dc( new CDAQControl() );
itsDAQControl = dc;
}

CMDAQ::~CMDAQ()
{
}
}

thanks

Bill

[Brandon Bray [MSFT]]

Re: auto_ptr in managed code

Bill Burris wrote:[color=blue]
> How do I use auto_ptr in managed C++?
>
> [SNIP]
>
> If I change this code to the following, I get "error C3633: cannot define
> itsDAQControl as a member of managed Alta::CMDAQ"
> ...
> private:
> std::auto_ptr< CDAQControl > itsDAQControl;[/color]

Hi Bill,
Unfortunately, you cannot do this with the current C++ language. auto_ptr
is a native class, and it is not possible to embed that class in a __gc
class. I realize this is a burden, and believe me -- we are working to
improve this situation.

The next version of the Visual C++ will allow you to write a different
auto_ptr template that would achieve what you are trying to do.

Cheerio!

--
Brandon Bray Visual C++ Compiler
This posting is provided AS IS with no warranties, and confers no rights.

[Bill Burris]

Re: auto_ptr in managed code


"Brandon Bray [MSFT]" <branbray@onlin e.microsoft.com > wrote in message
news:OjjrWYyfDH A.2344@TK2MSFTN GP10.phx.gbl...
[color=blue]
> auto_ptr
> is a native class, and it is not possible to embed that class in a __gc
> class. I realize this is a burden, and believe me -- we are working to
> improve this situation.[/color]

What other native classes are not usable in a _gc class?

I use managed C++ as the bridge between my native C++ code and C#. If I was
doing pure .NET code, I would use C#.

Bill

[Brandon Bray [MSFT]]

Re: auto_ptr in managed code

Bill Burris wrote:[color=blue]
> What other native classes are not usable in a _gc class?[/color]

With one exception, all native classes cannot be embedded in a __gc class.
The exception is POD types (a POD is short for "plain old data" and is a
class that neither has a user defined copy constructor nor a user defined
destructor, and contains only other PODs or scalar data).
[color=blue]
> I use managed C++ as the bridge between my native C++ code and C#. If I
> was doing pure .NET code, I would use C#.[/color]

I understand your position. This too is a sentiment we are looking to fix in
the next version of Visual C++.

Cheerio!

--
Brandon Bray Visual C++ Compiler
This posting is provided AS IS with no warranties, and confers no rights.

[Bill Burris]

C++ destructor in MC++ Re: auto_ptr in managed code

"Brandon Bray [MSFT]" <branbray@onlin e.microsoft.com > wrote in message
news:uTSmSCXhDH A.4088@tk2msftn gp13.phx.gbl...[color=blue]
>
> With one exception, all native classes cannot be embedded in a __gc class.
> The exception is POD types (a POD is short for "plain old data" and is a
> class that neither has a user defined copy constructor nor a user defined
> destructor, and contains only other PODs or scalar data).
>[/color]

I have been using destructors in my managed C++. It seems to work ok.

Some __gc code which uses native classes:

CMDAQ::CMDAQ( IMessageHandler * pMessageHandler , int siteId, int
interfaceType )
{
itsMessageDispa tcher = new CMessageDispatc her();
itsMessageDispa tcher->itsMessageHand ler = pMessageHandler ;
CDebug::Initial ize( itsMessageDispa tcher );
try
{
itsDAQControl = new CDAQControl( itsMessageDispa tcher, siteId,
interfaceType );
itsHistogramGro up = itsDAQControl->GetHistogramGr oup();
itsPhantomHisto gramGroup = itsDAQControl->GetPhantomHist ogramGroup();
}
catch( char* str )
{
itsMessageDispa tcher->DebugMessage ( str );
throw( new System::Excepti on( str ) );
}
}

CMDAQ::~CMDAQ()
{
delete itsDAQControl;
delete itsMessageDispa tcher;
}

This is used in my C# code as follows:

public class DAQ
{
private static CMDAQ itsDaq = null;
private IMessageHandler itsMessageHandl er;

public DAQ( IMessageHandler messageHandler, int interfaceType, int
siteId )
{
itsMessageHandl er = messageHandler;
itsDaq = new CMDAQ( itsMessageHandl er, siteId, interfaceType );
}

public void Dispose()
{
itsDaq.__dtor() ;
}

Dispose is called in the OnClosing funtion for my Form:

protected override void OnClosing( CancelEventArgs e )
{
base.OnClosing( e );
if( itsState == ProgState.DAQ )
{
itsDaq.Stop();
itsDaq.Dispose( );
itsSettings.Sav e( @"c:\alta_prog\ 33\ProgramSetti ngs.xml" );
}
}

Bill

[Bill Burris]

more I/O support is needed in .NET Re: auto_ptr in managed code

"Brandon Bray [MSFT]" <branbray@onlin e.microsoft.com > wrote in message
news:uTSmSCXhDH A.4088@tk2msftn gp13.phx.gbl...[color=blue]
> Bill Burris wrote:[color=green]
> > I use managed C++ as the bridge between my native C++ code and C#. If I
> > was doing pure .NET code, I would use C#.[/color]
>
> I understand your position. This too is a sentiment we are looking to fix[/color]
in[color=blue]
> the next version of Visual C++.[/color]

Even better would be if I could do everything in C#. For that to happen I
need serial port support in .NET, or device drivers for Motorola GPS
receivers which are usable in .NET. Also Measurement Computing
http://www.measurementcomputing.com/, hardware needs to be accessible from
..NET, and a .NET version of Tetradyne DriverX
http://www.tetradyne.com/driverx.htm.

Support for USB would also come in handy. I tried to roll my own but didn't
get very far. What I did do is posted at
http://www.componentsnotebook.com/no.../deviceio.aspx.

Bill