defaultvalue

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

For more information, see Attribute Contexts.

See Also

Concepts

IDL Attributes

Parameter Attributes

out (C++)

retval

in (C++)

pointer_default

unique (C++)

ATL Samples