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source (C++)

On a class, specifies the COM object's source interfaces for connection points. On a property or method, indicates that the member returns an object or VARIANT that is a source of events.

[ source(
) ]


One or more interfaces that you specify when you apply the source attribute to a class. This parameter is not used when source is applied to a property or method.

The source C++ attribute has the same functionality as the source MIDL attribute.

You can use the default attribute to specify the default source interface for an object.

// cpp_attr_ref_source.cpp
// compile with: /LD
#include "windows.h"
#include "unknwn.h"

[object, uuid(11111111-1111-1111-1111-111111111111)]
__interface b
   [id(0), propget, bindable, displaybind, defaultbind, requestedit]
   HRESULT get_I([out, retval]long *i);

[object, uuid(11111111-1111-1111-1111-111111111131)]
__interface c
   [id(0), propget, bindable, displaybind, defaultbind, requestedit] 
   HRESULT et_I([out, retval]long *i);

[coclass, default(c), uuid(11111111-1111-1111-1111-111111111132)]
class N : public b

[coclass, source(c), default(b, c), uuid(11111111-1111-1111-1111-111111111133)]
class NN : public b

Attribute Context

Applies to

class, struct, interface



Required attributes

coclass (when applied to class or struct)

Invalid attributes


For more information about the attribute contexts, see Attribute Contexts.