A scalar IDL_VARIABLE is distinguished by not having the IDL_V_ARR bit set in its flags field. A scalar variable must have one of the basic data types (IDL structures are never scalar) shown in the table below. The data for a scalar variable is stored in the IDL_VARIABLE itself, using the IDL_ALLTYPES union. The following table gives the relationship between the data type and the field used.

Scalar Data Type	Field That Stores Data
IDL_TYP_UNDEF	None
IDL_TYP_BYTE	value.c
IDL_TYP_INT	value.i
IDL_TYPE_UINT	value.ui
IDL_TYP_LONG	value.l
IDL_TYP_ULONG	value.ul
IDL_TYP_LONG64	value.l64
IDL_TYP_ULONG64	value.ul64
IDL_TYP_FLOAT	value.f
IDL_TYP_DOUBLE	value.d
IDL_TYP_COMPLEX	value.cmp
IDL_TYP_STRING	value.dcmp
IDL_TYP_PTR	value.str
IDL_TYP_OBJ	value.hvid