Question about the dreaded MC++

[songie D]

Can managed C++ be trusted to handle the garbage collector correctly in the
right bit if I have a project with unmanaged and managed parts in it?

[Ronald Laeremans [MSFT]]

Yes.

Is there something more specific you are after?

Ronald Laeremans
Visual C++ team

"songie D" <so****@D.com > wrote in message
news:%2******** *******@tk2msft ngp13.phx.gbl.. .

Can managed C++ be trusted to handle the garbage collector correctly in
the
right bit if I have a project with unmanaged and managed parts in it?

[songie D]

> Yes.

OK, good! I'd heard rumours that you "constantly have to worry about what
the gc's doing", but I've not ran into any problems with that, as yet.

Is there something more specific you are after?
ermm...yes, now you come to mention it.
I'm trying to add
using namespace System::Runtime ::InteropServic es;

to my project, but it gives the error

C:\Program Files\Microsoft Visual Studio .NET
2003\Vc7\Platfo rmSDK\Include\W inBase.h(3139) : error C2872: 'FILETIME' :
ambiguous symbol

could be 'C:\Program Files\Microsoft Visual Studio .NET
2003\Vc7\Platfo rmSDK\Include\W inDef.h(354) : _FILETIME FILETIME'

or 'stdafx.cpp(0) : System::Runtime ::InteropServic es::FILETIME'

many times. I can get round it by putting the explicit namespace name
preceeding all calls to the namespace, but that's a bit cumbersome. Any idea
how I can resolve it?

Also, for having an unmanaged function in one separate .cpp file, and the
managed code in what the IDE gives you (i.e. Form1.h), how would I link to
the unmanaged function, using extern "C"? or other?
Would I have to put #pragma unmanaged round the declaration?

Ronald Laeremans
Visual C++ team

"songie D" <so****@D.com > wrote in message
news:%2******** *******@tk2msft ngp13.phx.gbl.. .

Can managed C++ be trusted to handle the garbage collector correctly in
the
right bit if I have a project with unmanaged and managed parts in it?

[Tomas Restrepo \(MVP\)]

Songie,

ermm...yes, now you come to mention it.
I'm trying to add
using namespace System::Runtime ::InteropServic es;

to my project, but it gives the error

C:\Program Files\Microsoft Visual Studio .NET
2003\Vc7\Platfo rmSDK\Include\W inBase.h(3139) : error C2872: 'FILETIME' :
ambiguous symbol

could be 'C:\Program Files\Microsoft Visual Studio .NET
2003\Vc7\Platfo rmSDK\Include\W inDef.h(354) : _FILETIME FILETIME'

or 'stdafx.cpp(0) : System::Runtime ::InteropServic es::FILETIME'

many times. I can get round it by putting the explicit namespace name
preceeding all calls to the namespace, but that's a bit cumbersome. Any idea how I can resolve it?
Using a typedef is a simple way around it:

typedef System::Runtime ::InteropServic es::FILETIME NETFT;

NETFT tm....;


Also, for having an unmanaged function in one separate .cpp file, and the
managed code in what the IDE gives you (i.e. Form1.h), how would I link to
the unmanaged function, using extern "C"? or other?
Header files would work just fine.
Would I have to put #pragma unmanaged round the declaration?

nope. You might want to put it on the definition of the function if you
really want to ensure the compiler generates x86 code (instead of CIL) for
it, though (although you could simply compile the containing .cpp file
without /clr, as well).

--
Tomas Restrepo
to****@mvps.org

[mccoyn]

Your problem is you are including a header, probally windows.h, after the using namespace statement. Just put all your includes before the using namespace statements to get rid of the errors

There are some other problems with using the windows.h file and .Net in the same file. For example MessageBox is a macro, so if your trying to get System::Windows ::Forms::Messag eBox, you may find the compilier looking for System::Windows ::Forms::Messag eBoxA. To get around this you have to use #undef for the macro after including the header. This one is only a problem if you try to use MessageBox.

[songie D]

There are no files with '#include' statements AND 'using namespace' statements
The 'Form1.h' has 'using namespace' statements, and the stdafx.h has '#include <windows.h>'
There's no file in which there's both.

[songie D]

How would I compile one file without /clr and the rest with /clr, while building the project all at once?

[Arnaud Debaene]

"Ronald Laeremans [MSFT]" <ro*****@online .microsoft.com> wrote in message news:<#Z******* *******@TK2MSFT NGP09.phx.gbl>. ..

Yes.

Is there something more specific you are after?

Well, I must say I ran into a few problems with mixed MC++ / C++ when
you make heavy use of the RAII idiom : the .NET runtime seems to have
difficulties with tracking lifetime of parameters, which can have some
nasty side effects, even i f they are not related to GC.

See http://groups.google.com/groups?hl=f....vc.language.*
for the last dirty one.

Arnaud
MVP - VC

[Tomas Restrepo \(MVP\)]

Songie,

How would I compile one file without /clr and the rest with /clr, while

building the project all at once?

Select the file in question in solution explorer, and use the properties
dialog box to configure compiler arguments.

--
Tomas Restrepo
to****@mvps.org

[songie D]

mmm... ok. You can do this, yes

I've given up on using managed c++ anyway now, it seems that passing arrays is a whole lot more difficul
than it is in c#, even though its in the same assembly. See further up posts.