"Managed extensions" pinning question

[Ioannis Vranos]

Consider the code:


wchar_t __pin *p= &(someCommand->ToCharArray())[0];

_wsystem(p);

p=0;




I need to pin the wchar_t __gc [] because I need to pass it to
_wsystem() which takes a wchar_t *.


Does the above code pin the whole wchar_t __gc[]?

 

[Tomas Restrepo \(MVP\)]

Ioannis,

Consider the code:
wchar_t __pin *p= &(someCommand->ToCharArray())[0];

_wsystem(p);

p=0;

I need to pin the wchar_t __gc [] because I need to pass it to
_wsystem() which takes a wchar_t *.
Does the above code pin the whole wchar_t __gc[]?

Yep. From the MC++ spec, section 7.7 "Pinning Pointers":

"Pinning a sub-object defined in a managed object has the effect of pinning
the entire object. For example, if any element of an array is pinned, then
the whole array is also pinned. There are no extensions to the language for
declaring a pinned array. To pin an array, declare a pinning pointer to its
element type, and pin one of its elements.".

 

[Ioannis Vranos]

Yep. From the MC++ spec, section 7.7 "Pinning Pointers":

"Pinning a sub-object defined in a managed object has the effect of pinning
the entire object. For example, if any element of an array is pinned, then
the whole array is also pinned. There are no extensions to the language for
declaring a pinned array. To pin an array, declare a pinning pointer to its
element type, and pin one of its elements.".

OK thanks. Where can I find that spec?

 

[Carl Daniel [VC++ MVP]]

OK thanks. Where can I find that spec?

It's in the /vc7 directory of a Visual Studio .NET 2002/3 installation -
ManagedExtensionsSpec.doc

-cd

 

[Ioannis Vranos]

It's in the /vc7 directory of a Visual Studio .NET 2002/3 installation -
ManagedExtensionsSpec.doc

OK thanks.

 

[Nishant S]

On a side note, it's not a very good idea to invest time on the old syntax.
You should try and move to the new C++/CLI syntax.

 

[Carl Daniel [VC++ MVP]]

On a side note, it's not a very good idea to invest time on the old
syntax. You should try and move to the new C++/CLI syntax.

Unless you plan to ship something in the next 9 months that is.

-cd

 

[Nishant S]

Yep, good point

--
Regards,
Nish [VC++ MVP]
http://www.voidnish.com /* MVP tips tricks and essays web site */
http://blog.voidnish.com /* My blog on C++/CLI, MFC, Whidbey, CLR... */