Questions on __value class

[Simon Cheng]

Hi,

In C#, value types are derived from System.ValueType (and hence from
System.Object).

Does this hold true for MC++?

__value class ValueClass {...};

Is ValueClass above derived from System::ValueType (and hence from
System::Object)?

Thanks,
Simon

[Jochen Kalmbach]

Simon Cheng wrote:

In C#, value types are derived from System.ValueType (and hence from
System.Object).

Does this hold true for MC++?

__value class ValueClass {...};

Is ValueClass above derived from System::ValueType (and hence from
System::Object)?

Yes.

--
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Jochen

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[Jochen Kalmbach]

Simon Cheng wrote:

__value class ValueClass {...};

For more info see: __value Classes
http://msdn.microsoft.com/library/en-
us/vcmxspec/html/vcManagedExtensionsSpec_5.asp

--
Greetings
Jochen

Do you need a memory-leak finder ?
http://www.codeproject.com/tools/leakfinder.asp

Do you need daily reports from your server?
http://sourceforge.net/projects/srvreport/

[Simon Cheng]

Thanks, Jochen. The next question:

The derivation chain for ValueClass is:

System::Object
System::ValueType
ValueClass

Why objects derived from System::ValueType (_indirectly_ from
System::Object) are always allocated on stack, whereas objects derived
_directly_ from System::Object are always allocated on CLR heap? This means
if a value object calls a method inherited from System::Object but doesn't
override it, then the object needs to be boxed before the call can be made.
Is this just how it is designed?

Simon

"Jochen Kalmbach" <no********************@holzma.de> wrote in message
news:Xn**********************************@207.46.2 48.16...

Simon Cheng wrote:

__value class ValueClass {...};

For more info see: __value Classes
http://msdn.microsoft.com/library/en-
us/vcmxspec/html/vcManagedExtensionsSpec_5.asp

--
Greetings
Jochen

Do you need a memory-leak finder ?
http://www.codeproject.com/tools/leakfinder.asp

Do you need daily reports from your server?
http://sourceforge.net/projects/srvreport/

[Doug Harrison [MVP]]

Simon Cheng wrote:

The derivation chain for ValueClass is:

System::Object
System::ValueType
ValueClass

Why objects derived from System::ValueType (_indirectly_ from
System::Object) are always allocated on stack, whereas objects derived
_directly_ from System::Object are always allocated on CLR heap? This means
if a value object calls a method inherited from System::Object but doesn't
override it, then the object needs to be boxed before the call can be made.
Is this just how it is designed?

That's pretty accurate. Here are a couple of articles that give some
background on value types:

CLR Design Choices
A Conversation with Anders Hejlsberg, Part VIII
Value Types
http://www.artima.com/intv/choices3.html

Value Types
http://blogs.msdn.com/cbrumme/archiv.../10/51425.aspx
--
Doug Harrison
Microsoft MVP - Visual C++

[Simon Cheng]

Thanks for the pointers. They are good read.

Simon

"Doug Harrison [MVP]" <ds*@mvps.org> wrote in message
news:o7********************************@4ax.com...

Simon Cheng wrote:

The derivation chain for ValueClass is:

System::Object
System::ValueType
ValueClass

Why objects derived from System::ValueType (_indirectly_ from
System::Object) are always allocated on stack, whereas objects derived
_directly_ from System::Object are always allocated on CLR heap? This meansif a value object calls a method inherited from System::Object but doesn'toverride it, then the object needs to be boxed before the call can be made.Is this just how it is designed?

That's pretty accurate. Here are a couple of articles that give some
background on value types:

CLR Design Choices
A Conversation with Anders Hejlsberg, Part VIII
Value Types
http://www.artima.com/intv/choices3.html

Value Types
http://blogs.msdn.com/cbrumme/archiv.../10/51425.aspx
--
Doug Harrison
Microsoft MVP - Visual C++