The __abstract managed C++ extension

[Edward Diener]

In the Managed Extensions for C++ Reference, I read:

"Applying __abstract to a class or structure does not imply that the result
is a __gc class or __gc structure."

However in the Managed Extensions for C++ Specification I immediately read:

"The __abstract keyword can only be applied to a __gc class or __gc
interface."

which contradicts the previous assertion.

So the question is: can __abstract be applied to a non __gc class/interface,
and if so when would it be used ?

[Ronald Laeremans [MSFT]]

It means:

__abstract class Foo {}; // Error: __abstract does not imply __gc or
__interface
__abstract __gc class Foo {}; // OK
__abstract __gc __interface IFoo {}; // OK

Ronald Laeremans
Visual C++ team

"Edward Diener" <ed******@tropicsoft.com> wrote in message
news:u8****************@TK2MSFTNGP12.phx.gbl...

In the Managed Extensions for C++ Reference, I read:

"Applying __abstract to a class or structure does not imply that the result is a __gc class or __gc structure."

However in the Managed Extensions for C++ Specification I immediately read:
"The __abstract keyword can only be applied to a __gc class or __gc
interface."

which contradicts the previous assertion.

So the question is: can __abstract be applied to a non __gc class/interface, and if so when would it be used ?

[Edward Diener]

Ronald Laeremans [MSFT] wrote:

It means:

__abstract class Foo {}; // Error: __abstract does not imply __gc or
__interface
__abstract __gc class Foo {}; // OK
__abstract __gc __interface IFoo {}; // OK
Wouldn't it have been more logical, therefore, to have __abstract always
mean __gc also ?

Ronald Laeremans
Visual C++ team

"Edward Diener" <ed******@tropicsoft.com> wrote in message
news:u8****************@TK2MSFTNGP12.phx.gbl...

In the Managed Extensions for C++ Reference, I read:

"Applying __abstract to a class or structure does not imply that the
result is a __gc class or __gc structure."

However in the Managed Extensions for C++ Specification I
immediately read:

"The __abstract keyword can only be applied to a __gc class or __gc
interface."

which contradicts the previous assertion.

So the question is: can __abstract be applied to a non __gc
class/interface, and if so when would it be used ?

[Ronald Laeremans [MSFT]]

We feel that it doesn't. For one because we reserve the right to have it
work with non __gc classes at some point in the future. But more importantly
because at least the concept "abstract" is completely orthogonal to the
concept of "gc-ness" despite the current implementation.

Ronald

"Edward Diener" <ed******@tropicsoft.com> wrote in message
news:e6**************@TK2MSFTNGP10.phx.gbl...

Ronald Laeremans [MSFT] wrote:

It means:

__abstract class Foo {}; // Error: __abstract does not imply __gc or
__interface
__abstract __gc class Foo {}; // OK
__abstract __gc __interface IFoo {}; // OK

Wouldn't it have been more logical, therefore, to have __abstract always
mean __gc also ?

Ronald Laeremans
Visual C++ team

"Edward Diener" <ed******@tropicsoft.com> wrote in message
news:u8****************@TK2MSFTNGP12.phx.gbl...

In the Managed Extensions for C++ Reference, I read:

"Applying __abstract to a class or structure does not imply that the
result is a __gc class or __gc structure."

However in the Managed Extensions for C++ Specification I
immediately read:

"The __abstract keyword can only be applied to a __gc class or __gc
interface."

which contradicts the previous assertion.

So the question is: can __abstract be applied to a non __gc
class/interface, and if so when would it be used ?