implements (C++)
The latest version of this topic can be found at implements (C++).
Specifies dispatch interfaces that are forced to be members of the IDL coclass.
Syntax
[ implements(
interfaces={interfaces},
dispinterfaces={dispinterfaces}
)]
Parameters
interfaces
A comma separated list of the interfaces that will be a member of the IDL coclass. A shorthand method for specifying a single interface is implements(interface_name).
dispinterfaces
A comma separated list of the dispinterface that will be a member of the IDL coclass. A shorthand method for specifying a single dispinterface is implements(dispinterfaces = dispinterface_name**)**.
Remarks
By default, only COM-interfaces that are base classes of the coclass are added in the IDL coclass. implements lets you force other interfaces to be IDL coclass members.
Requirements
Attribute Context
| Applies to | class, struct |
| Repeatable | Yes |
| Required attributes | None |
| Invalid attributes | None |
For more information, see Attribute Contexts.
Example
The following example is in three parts: an .idl file and its associated .h file, and a C++ file.
Assume the following .idl file, which will be available to the compiler.
// attr_implements.idl
import "docobj.idl";
[ version(1.0), uuid(0ed71801-a1b6-3178-af3b-9431fc00185e) ]
library odod
{
importlib("stdole2.tlb");
importlib("olepro32.dll");
[
object,
uuid(1AECC9BB-2104-3723-98B8-7CC54722C7DD)
]
interface IBar1 {
[id(1)] HRESULT bar1();
};
[
dual,
uuid(1AECCABB-2104-3723-98B8-7CC54722C7DD)
]
interface IBar2 {
[id(1)] HRESULT bar2();
};
[
uuid(1AECC9CC-2104-3723-98B8-7CC54722C7DD)
]
dispinterface ISna {
properties:
methods:
[id(1)] HRESULT sna();
};
[
uuid(159A9BBB-E5F1-33F6-BEF5-6CFAD7A5933F),
version(1.0)
]
coclass CBar {
interface IBar1;
interface IBar2;
dispinterface ISna;
};
}
Example
And the following .h file, which also needs to be available to the compiler.
// attr_implements.h
// this ALWAYS GENERATED file contains definitions for the interfaces
/* File created by MIDL compiler version 6.00.0361 */
/* at Mon Feb 28 16:30:53 2005 */
/* Compiler settings for attr_implements.idl:
Oicf, W1, Zp8, env=Win32 (32b run)
protocol : dce , ms_ext, c_ext, robust
error checks: allocation ref bounds_check enum stub_data
VC __declspec() decoration level:
__declspec(uuid()), __declspec(selectany), __declspec(novtable)
DECLSPEC_UUID(), MIDL_INTERFACE()
*/
//@@MIDL_FILE_HEADING( )
#pragma warning( disable: 4049 ) /* more than 64k source lines */
/* verify that the <rpcndr.h> version is high enough to compile this file*/
#ifndef __REQUIRED_RPCNDR_H_VERSION__
#define __REQUIRED_RPCNDR_H_VERSION__ 475
#endif
#include "rpc.h"
#include "rpcndr.h"
#ifndef __RPCNDR_H_VERSION__
#error this stub requires an updated version of <rpcndr.h>
#endif // __RPCNDR_H_VERSION__
#ifndef __attr_implements_h__
#define __attr_implements_h__
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
#pragma once
#endif
/* Forward Declarations */
#ifndef __IBar1_FWD_DEFINED__
#define __IBar1_FWD_DEFINED__
typedef interface IBar1 IBar1;
#endif /* __IBar1_FWD_DEFINED__ */
#ifndef __IBar2_FWD_DEFINED__
#define __IBar2_FWD_DEFINED__
typedef interface IBar2 IBar2;
#endif /* __IBar2_FWD_DEFINED__ */
#ifndef __ISna_FWD_DEFINED__
#define __ISna_FWD_DEFINED__
typedef interface ISna ISna;
#endif /* __ISna_FWD_DEFINED__ */
#ifndef __CBar_FWD_DEFINED__
#define __CBar_FWD_DEFINED__
#ifdef __cplusplus
typedef class CBar CBar;
#else
typedef struct CBar CBar;
#endif /* __cplusplus */
#endif /* __CBar_FWD_DEFINED__ */
/* header files for imported files */
#include "docobj.h"
#ifdef __cplusplus
extern "C"{
#endif
void * __RPC_USER MIDL_user_allocate(size_t);
void __RPC_USER MIDL_user_free( void * );
#ifndef __odod_LIBRARY_DEFINED__
#define __odod_LIBRARY_DEFINED__
/* library odod */
/* [uuid][version] */
EXTERN_C const IID LIBID_odod;
#ifndef __IBar1_INTERFACE_DEFINED__
#define __IBar1_INTERFACE_DEFINED__
/* interface IBar1 */
/* [uuid][object] */
EXTERN_C const IID IID_IBar1;
#if defined(__cplusplus) && !defined(CINTERFACE)
MIDL_INTERFACE("1AECC9BB-2104-3723-98B8-7CC54722C7DD")
IBar1
{
public:
BEGIN_INTERFACE
virtual /* [id] */ HRESULT STDMETHODCALLTYPE bar1( void) = 0;
END_INTERFACE
};
#else /* C style interface */
typedef struct IBar1Vtbl
{
BEGIN_INTERFACE
/* [id] */ HRESULT ( STDMETHODCALLTYPE *bar1 )(
IBar1 * This);
END_INTERFACE
} IBar1Vtbl;
interface IBar1
{
CONST_VTBL struct IBar1Vtbl *lpVtbl;
};
#ifdef COBJMACROS
#define IBar1_bar1(This)\
(This)->lpVtbl -> bar1(This)
#endif /* COBJMACROS */
#endif /* C style interface */
/* [id] */ HRESULT STDMETHODCALLTYPE IBar1_bar1_Proxy(
IBar1 * This);
void __RPC_STUB IBar1_bar1_Stub(
IRpcStubBuffer *This,
IRpcChannelBuffer *_pRpcChannelBuffer,
PRPC_MESSAGE _pRpcMessage,
DWORD *_pdwStubPhase);
#endif /* __IBar1_INTERFACE_DEFINED__ */
#ifndef __IBar2_INTERFACE_DEFINED__
#define __IBar2_INTERFACE_DEFINED__
/* interface IBar2 */
/* [auto_handle][uuid][dual] */
EXTERN_C const IID IID_IBar2;
#if defined(__cplusplus) && !defined(CINTERFACE)
MIDL_INTERFACE("1AECCABB-2104-3723-98B8-7CC54722C7DD")
IBar2
{
public:
BEGIN_INTERFACE
virtual /* [id] */ HRESULT STDMETHODCALLTYPE bar2( void) = 0;
END_INTERFACE
};
#else /* C style interface */
typedef struct IBar2Vtbl
{
BEGIN_INTERFACE
/* [id] */ HRESULT ( STDMETHODCALLTYPE *bar2 )(
IBar2 * This);
END_INTERFACE
} IBar2Vtbl;
interface IBar2
{
CONST_VTBL struct IBar2Vtbl *lpVtbl;
};
#ifdef COBJMACROS
#define IBar2_bar2(This)\
(This)->lpVtbl -> bar2(This)
#endif /* COBJMACROS */
#endif /* C style interface */
/* [id] */ HRESULT STDMETHODCALLTYPE IBar2_bar2_Proxy(
IBar2 * This);
void __RPC_STUB IBar2_bar2_Stub(
IRpcStubBuffer *This,
IRpcChannelBuffer *_pRpcChannelBuffer,
PRPC_MESSAGE _pRpcMessage,
DWORD *_pdwStubPhase);
#endif /* __IBar2_INTERFACE_DEFINED__ */
#ifndef __ISna_DISPINTERFACE_DEFINED__
#define __ISna_DISPINTERFACE_DEFINED__
/* dispinterface ISna */
/* [uuid] */
EXTERN_C const IID DIID_ISna;
#if defined(__cplusplus) && !defined(CINTERFACE)
MIDL_INTERFACE("1AECC9CC-2104-3723-98B8-7CC54722C7DD")
ISna : public IDispatch
{
};
#else /* C style interface */
typedef struct ISnaVtbl
{
BEGIN_INTERFACE
HRESULT ( STDMETHODCALLTYPE *QueryInterface )(
ISna * This,
/* [in] */ REFIID riid,
/* [iid_is][out] */ void **ppvObject);
ULONG ( STDMETHODCALLTYPE *AddRef )(
ISna * This);
ULONG ( STDMETHODCALLTYPE *Release )(
ISna * This);
HRESULT ( STDMETHODCALLTYPE *GetTypeInfoCount )(
ISna * This,
/* [out] */ UINT *pctinfo);
HRESULT ( STDMETHODCALLTYPE *GetTypeInfo )(
ISna * This,
/* [in] */ UINT iTInfo,
/* [in] */ LCID lcid,
/* [out] */ ITypeInfo **ppTInfo);
HRESULT ( STDMETHODCALLTYPE *GetIDsOfNames )(
ISna * This,
/* [in] */ REFIID riid,
/* [size_is][in] */ LPOLESTR *rgszNames,
/* [in] */ UINT cNames,
/* [in] */ LCID lcid,
/* [size_is][out] */ DISPID *rgDispId);
/* [local] */ HRESULT ( STDMETHODCALLTYPE *Invoke )(
ISna * This,
/* [in] */ DISPID dispIdMember,
/* [in] */ REFIID riid,
/* [in] */ LCID lcid,
/* [in] */ WORD wFlags,
/* [out][in] */ DISPPARAMS *pDispParams,
/* [out] */ VARIANT *pVarResult,
/* [out] */ EXCEPINFO *pExcepInfo,
/* [out] */ UINT *puArgErr);
END_INTERFACE
} ISnaVtbl;
interface ISna
{
CONST_VTBL struct ISnaVtbl *lpVtbl;
};
#ifdef COBJMACROS
#define ISna_QueryInterface(This,riid,ppvObject)\
(This)->lpVtbl -> QueryInterface(This,riid,ppvObject)
#define ISna_AddRef(This)\
(This)->lpVtbl -> AddRef(This)
#define ISna_Release(This)\
(This)->lpVtbl -> Release(This)
#define ISna_GetTypeInfoCount(This,pctinfo)\
(This)->lpVtbl -> GetTypeInfoCount(This,pctinfo)
#define ISna_GetTypeInfo(This,iTInfo,lcid,ppTInfo)\
(This)->lpVtbl -> GetTypeInfo(This,iTInfo,lcid,ppTInfo)
#define ISna_GetIDsOfNames(This,riid,rgszNames,cNames,lcid,rgDispId)\
(This)->lpVtbl -> GetIDsOfNames(This,riid,rgszNames,cNames,lcid,rgDispId)
#define ISna_Invoke(This,dispIdMember,riid,lcid,wFlags,pDispParams,pVarResult,pExcepInfo,puArgErr)\
(This)->lpVtbl -> Invoke(This,dispIdMember,riid,lcid,wFlags,pDispParams,pVarResult,pExcepInfo,puArgErr)
#endif /* COBJMACROS */
#endif /* C style interface */
#endif /* __ISna_DISPINTERFACE_DEFINED__ */
EXTERN_C const CLSID CLSID_CBar;
#ifdef __cplusplus
class DECLSPEC_UUID("159A9BBB-E5F1-33F6-BEF5-6CFAD7A5933F")
CBar;
#endif
#endif /* __odod_LIBRARY_DEFINED__ */
/* Additional Prototypes for ALL interfaces */
/* end of Additional Prototypes */
#ifdef __cplusplus
}
#endif
#endif
Example
In the following program, without implements, IBar1, IBar2, and ISna will not be in the coclass in the generated IDL.
// attr_implements.cpp
// compile with: /LD /link /idlout:out.idl
#define _ATL_ATTRIBUTES 1
#include <atlbase.h>
#include <atlcom.h>
#include "attr_implements.h" // IDL generated header that contains a definition of the pseudo-interface IBar and pseudo-dispinterface ISna
[module(name = "MyLib")];
[dispinterface, uuid("00000000-0000-0000-0000-000000000001")]
__interface IMyInterface
{
[id(0)] long x;
[id(1)] HRESULT func();
};
[
coclass,
uuid("00000000-0000-0000-0000-000000000002"),
implements(interfaces={IBar1,IBar2}, dispinterfaces=ISna)
]
class CMyClass : public IMyInterface,
public IBar1,
public IDispatchImpl<IBar2, &__uuidof(IBar2)>,
public ISna
{
long _x;
public:
long get_x() { return _x; }
void put_x(long x0) { _x = x0; }
HRESULT func() { return S_OK; }
HRESULT __stdcall bar1() { return S_OK; }
HRESULT __stdcall bar2() { return S_OK; }
HRESULT __stdcall sna() { return S_OK; }
virtual HRESULT STDMETHODCALLTYPE ISna::Invoke(
/* [in] */ DISPID dispIdMember,
/* [in] */ REFIID riid,
/* [in] */ LCID lcid,
/* [in] */ WORD wFlags,
/* [out][in] */ DISPPARAMS *pDispParams,
/* [out] */ VARIANT *pVarResult,
/* [out] */ EXCEPINFO *pExcepInfo,
/* [out] */ UINT *puArgErr)
{
HRESULT hr = S_OK;
if (pDispParams == 0) {
return DISP_E_BADVARTYPE;
}
if (pDispParams->cArgs > 0) {
return DISP_E_BADPARAMCOUNT;
}
if (pVarResult != 0) {
::VariantInit(pVarResult);
}
switch (dispIdMember) {
case 1:
{
if (pDispParams->cArgs != 0) {
return DISP_E_BADPARAMCOUNT;
}
hr = this->sna();
break;
}
default:
return DISP_E_MEMBERNOTFOUND;
}
return hr;
}
virtual HRESULT STDMETHODCALLTYPE ISna::GetIDsOfNames(
/* [in] */ REFIID riid,
/* [size_is][in] */ LPOLESTR *rgszNames,
/* [in] */ UINT cNames,
/* [in] */ LCID lcid,
/* [size_is][out] */ DISPID *rgDispId)
{
static LPOLESTR names[] = { L"sna" };
static DISPID dids[] = { 1 };
for (unsigned int i = 0; i < cNames; ++i) {
int fFoundIt = 0;
for (unsigned int j = 0; j < sizeof(names)/sizeof(LPOLESTR); ++j) {
if (lstrcmpiW(rgszNames[i], names[j]) == 0) {
fFoundIt = 1;
rgDispId[i] = dids[j];
break;
}
}
if (fFoundIt == 0) {
return DISP_E_UNKNOWNNAME;
}
}
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE ISna::GetTypeInfoCount(unsigned int* pctinfo)
{
if (pctinfo == NULL) {
return E_POINTER;
}
CComPtr<ITypeInfo> spTypeInfo;
*pctinfo =
(SUCCEEDED(TypeInfoHelper(__uuidof(ISna), 0, &spTypeInfo))) ? 1 : 0;
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE ISna::GetTypeInfo(unsigned int iTInfo, LCID lcid, ITypeInfo** ppTInfo)
{
if (iTInfo != 0) {
return DISP_E_BADINDEX;
}
return TypeInfoHelper(__uuidof(ISna), lcid, ppTInfo);
}
BEGIN_COM_MAP(CMyClass)
COM_INTERFACE_ENTRY(IBar1)
COM_INTERFACE_ENTRY(IBar2)
COM_INTERFACE_ENTRY(ISna)
END_COM_MAP()
};