digitalmars.D.learn - Strange behavior
- yvad (53/53) Mar 25 2008 I have 2 modules.
- Jarrett Billingsley (10/23) Mar 25 2008 Before you go too far with this, you should know that while D has suppor...
- John C (2/7) Mar 25 2008 Actually, any interface called IUnknown will do - it needn't be the one ...
- John C (2/3) Mar 25 2008 I'm surprised that's the error you get. Copying your code (and filling i...
- yvad (2/7) Mar 25 2008 I tried. Same error
- John C (2/3) Mar 25 2008 Further to my other reply ... The compiler is complaining because the fu...
I have 2 modules.
// IUnknown.d
module IUnknown;
pragma(lib, "ole32.lib");
public import HRESULT;
extern (C) {
const GUID IID_IUnknown;
}
extern (Windows) {
interface IUnknown {
HRESULT QueryInterface(in GUID* riid, out void* ppvObject);
uint AddRef();
uint Release();
}
}
abstract class AbstractUnknown : IUnknown {
extern (Windows):
// IUnknown
HRESULT QueryInterface(GUID* riid, out void* ppvObject);
uint AddRef() {
....
}
uint Release() {
....
}
}
// and IClassFactory.d
module win32.api.com.interfaces.IClassFactory;
pragma(lib, "ole32.lib");
public import IUnknown;
extern (C) {
const GUID IID_IClassFactory;
}
extern (Windows) {
interface IClassFactory : IUnknown {
HRESULT CreateInstance(in IUnknown pUnknown, in GUID* riid, out
void* ppvObject);
HRESULT LockServer(in bool fLock);
}
}
abstract class AbstractClassFactory : AbstractUnknown, IClassFactory {
extern (Windows):
// IUnknown
HRESULT QueryInterface(in GUID* riid, out void* ppvObject) {
....
}
....
}
And I get an error on line in AbstractClassFactory "HRESULT QueryInterface(in
GUID* riid, out void* ppvObject) {":
Severity and Description Path Resource Location Creation Time Id
QueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject
ppvObject) overrides but is not covariant with QueryInterface of type
HRESULT(GUID * riidriid, void* ppvObject ppvObject)
import/win32/api/com/interfaces IClassFactory.d line 28 1206420149328
12010
if I comment line in AbstractUnknown with "HRESULT QueryInterface(in GUID*
riid, out void* ppvObject);" it compiles without any error.
Is it should be so or I am doing something wrong?
I have this error on dmd 1.028 and 2.012 on Windows.
Mar 25 2008
"yvad" <yannurov gmail.com> wrote in message
news:fsam2t$oo3$1 digitalmars.com...
And I get an error on line in AbstractClassFactory "HRESULT
QueryInterface(in GUID* riid, out void* ppvObject) {":
Severity and Description Path Resource Location Creation Time
Id
QueryInterface of type HRESULTWindows (GUID * riidriid, out void*
ppvObject ppvObject) overrides but is not covariant with QueryInterface of
type HRESULT(GUID * riidriid, void* ppvObject ppvObject)
import/win32/api/com/interfaces IClassFactory.d line 28
1206420149328 12010
if I comment line in AbstractUnknown with "HRESULT QueryInterface(in GUID*
riid, out void* ppvObject);" it compiles without any error.
Is it should be so or I am doing something wrong?
I have this error on dmd 1.028 and 2.012 on Windows.
Before you go too far with this, you should know that while D has support
for COM, that support is kind of "magical." The interface you should be
inheriting has already been defined for you in std.c.windows.com. (There's
also some stuff in std.windows.iunknown but I'm not sure what that's for.)
In std.c.windows.com there's IUnknown and a class called ComObject which
implements it, including QueryInterface, AddRef, and Release. The compiler
explicitly depends upon you deriving from this IUnknown and I don't know if
it will treat your interfaces as COM interfaces unless you do.
Mar 25 2008
John C <johnch_atms hotmail.com> Jarrett Billingsley Wrote:In std.c.windows.com there's IUnknown and a class called ComObject which implements it, including QueryInterface, AddRef, and Release. The compiler explicitly depends upon you deriving from this IUnknown and I don't know if it will treat your interfaces as COM interfaces unless you do.Actually, any interface called IUnknown will do - it needn't be the one defined in Phobos.
Mar 25 2008
yvad Wrote:QueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)I'm surprised that's the error you get. Copying your code (and filling in the blanks) I instead get an error about an undefined symbol. You need to mark QueryInterface in AbstractUnknown as abstract.
Mar 25 2008
John C Wrote:yvad Wrote:I tried. Same errorQueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)I'm surprised that's the error you get. Copying your code (and filling in the blanks) I instead get an error about an undefined symbol. You need to mark QueryInterface in AbstractUnknown as abstract.
Mar 25 2008
yvad Wrote:QueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)Further to my other reply ... The compiler is complaining because the function signatures don't match - one is lacking an "out" attribute. But the code you posted isn't missing the "out". Did you change the code before posting it here?
Mar 25 2008
John C Wrote:yvad Wrote:No. No chages. I also noticed missing out. This was reason I wrote hereQueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)Further to my other reply ... The compiler is complaining because the function signatures don't match - one is lacking an "out" attribute. But the code you posted isn't missing the "out". Did you change the code before posting it here?
Mar 25 2008
John C Wrote:yvad Wrote:I attached original filesQueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)Further to my other reply ... The compiler is complaining because the function signatures don't match - one is lacking an "out" attribute. But the code you posted isn't missing the "out". Did you change the code before posting it here?
Mar 25 2008
yvad Wrote:John C Wrote:Compiles OK for me. Be aware that "delete this" in your ref counting code will not free any memory. You should override AbstractUnknown's new and use malloc, then release the memory with free. Nor will COM objects get garbage collected.yvad Wrote:I attached original filesQueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)Further to my other reply ... The compiler is complaining because the function signatures don't match - one is lacking an "out" attribute. But the code you posted isn't missing the "out". Did you change the code before posting it here?
Mar 25 2008
John C Wrote:yvad Wrote:Sorry. The error appears only in Eclipse.Descent compilation. Thanks for "delete this". I will investigate it.John C Wrote:Compiles OK for me. Be aware that "delete this" in your ref counting code will not free any memory. You should override AbstractUnknown's new and use malloc, then release the memory with free. Nor will COM objects get garbage collected.yvad Wrote:I attached original filesQueryInterface of type HRESULTWindows (GUID * riidriid, out void* ppvObject ppvObject) overrides but is not covariant with QueryInterface of type HRESULT(GUID * riidriid, void* ppvObject ppvObject)Further to my other reply ... The compiler is complaining because the function signatures don't match - one is lacking an "out" attribute. But the code you posted isn't missing the "out". Did you change the code before posting it here?
Mar 25 2008