| title | defaultvalue | Microsoft Docs | |
|---|---|---|
| ms.custom | ||
| ms.date | 11/04/2016 | |
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| ms.tgt_pltfrm | ||
| ms.topic | language-reference | |
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| ms.assetid | efa5d050-b2cc-4d9e-9b8e-79954f218d3a | |
| caps.latest.revision | 11 | |
| author | mikeblome | |
| ms.author | mblome | |
| manager | ghogen |
Allows specification of a default value for a typed optional parameter.
[ defaultvalue= value ]
value
The default value for the parameter.
The defaultvalue C++ attribute has the same functionality as the defaultvalue MIDL attribute.
The following code shows an interface method using the defaultvalue attribute:
// cpp_attr_ref_defaultvalue.cpp
// compile with: /LD
#include <windows.h>
[export] typedef long HRESULT;
[export, ptr, string] typedef unsigned char * MY_STRING_TYPE;
[ uuid("479B29EE-9A2C-11D0-B696-00A0C903487A"),
dual, oleautomation,
helpstring("IFireTabCtrl Interface"),
helpcontext(122), pointer_default(unique) ]
__interface IFireTabCtrl : IDispatch {
[bindable, propget] HRESULT get_Size([out, retval, defaultvalue("33")] long *nSize);
[bindable, propput] HRESULT put_Size([in] int nSize);
};
[ module(name="ATLFIRELib", uuid="479B29E1-9A2C-11D0-B696-00A0C903487A",
version="1.0", helpstring="ATLFire 1.0 Type Library") ];
| Applies to | Interface parameter |
| Repeatable | No |
| Required attributes | None |
| Invalid attributes | None |
For more information, see Attribute Contexts.
IDL Attributes
Parameter Attributes
out
retval
in
pointer_default
unique