com-map-global-functions.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: COM Map Global Functions	COM Map Global Functions	11/04/2016	atlbase/ATL::AtlInternalQueryInterface atlbase/ATL::InlineIsEqualIUnknown	COM interfaces, COM map global functions	b9612d30-eb23-46ef-8093-d56f237d3cf1

COM Map Global Functions

These functions provide support for COM Map IUnknown implementations.

Function	Description
AtlInternalQueryInterface	Delegates to the IUnknown of a nonaggregated object.
InlineIsEqualIUnknown	Generates efficient code for comparing interfaces against IUnknown.

Requirements

Header: atlbase.h

AtlInternalQueryInterface

Retrieves a pointer to the requested interface.

HRESULT AtlInternalQueryInterface(
    void* pThis,
    const _ATL_INTMAP_ENTRY* pEntries,
    REFIID iid,
    void** ppvObject);

Parameters

pThis
[in] A pointer to the object that contains the COM map of interfaces exposed to QueryInterface.

pEntries
[in] An array of _ATL_INTMAP_ENTRY structures that access a map of available interfaces.

iid
[in] The GUID of the interface being requested.

ppvObject
[out] A pointer to the interface pointer specified in iid, or NULL if the interface is not found.

Return Value

One of the standard HRESULT values.

Remarks

AtlInternalQueryInterface only handles interfaces in the COM map table. If your object is aggregated, AtlInternalQueryInterface does not delegate to the outer unknown. You can enter interfaces into the COM map table with the macro COM_INTERFACE_ENTRY or one of its variants.

Example

[!code-cppNVC_ATL_Windowing#94]

InlineIsEqualIUnknown

Call this function, for the special case of testing for IUnknown.

BOOL InlineIsEqualUnknown(REFGUID rguid1);

Parameters

rguid1
[in] The GUID to compare to IID_IUnknown.

See also

Functions
COM Map Macros