Allows specification of a default value for a typed optional parameter.
[ defaultvalue= value ]
Parameters
- value
The default value for the parameter.
Remarks
The defaultvalue C++ attribute has the same functionality as the defaultvalue MIDL attribute.
Example
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") ];
Requirements
Attribute Context
Applies to |
Interface parameter |
Repeatable |
No |
Required attributes |
None |
Invalid attributes |
None |
For more information, see Attribute Contexts.