Used with the switch_type attribute in a union.

[ case(value) ]

value
A possible input value for which you want to provide processing. The type of value can be one of the following types:

• int

• char

• boolean

• enum

or an identifier of such a type.

The case C++ attribute has the same functionality as the case MIDL attribute. This attribute is only used with the switch_type attribute.

The following code shows a use of the case attribute:

// cpp_attr_ref_case.cpp
// compile with: /LD
#include <unknwn.h>
[export]
struct SizedValue2 {
   [switch_type(char), switch_is(kind)] union {
      [case(1), string]
          wchar_t* wval;
      [default, string]
          char* val;
   };
    char kind;
};
[module(name="ATLFIRELib")];

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

IDL Attributes
Typedef, Enum, Union, and Struct Attributes
Class Attributes