switch_type attribute
The [switch_type] attribute identifies the type of the variable used as the union discriminant. The switch type can be an integer, character, Boolean, or enumeration type.
switch_type(switch-type-specifier)
-
switch-type-specifier
-
Specifies an int, char, Boolean, or enum type, or an identifier of such a type.
While the [switch_type] attribute identifies the variable type, the [switch_is] attribute specifies the name of the parameter that is the union discriminant. The [switch_type] attribute applies to parameters or members of structures or unions.
The union and its discriminant must be specified at the same logical level. When the union is a parameter, the union discriminant must be another parameter. When the union is a field of a structure, the discriminant must be another field of the structure at the same level as the union field.
typedef [switch_type(short)] union _WILLIE_UNION_TYPE
{
[case(24)]
float fMays;
[case(25)]
double dMcCovey;
[default]
;
} WILLIE_UNION_TYPE;
typedef struct _WINNER_TYPE
{
[switch_is(sUniformNumber)] WILLIE_UNION_TYPE w;
short sUniformNumber;
} WINNER_TYPE;