Function

Summary

Sets the fields in a VARIANT pointer.

Package

com

Signature

set-variant variant type &optional value

Arguments

variant

A foreign pointer to an object of type VARIANT.

type

A keyword specifying the type of value.

value

The value to store in variant.

Description

The function set-variant can be used to set the type and value of a VARIANT object. It is useful if the default type provided by the automatic conversion for VARIANT return values is incorrect. The value of meaning of type is an specified below

Value of type	VT code used	Expected type of value
nil	dynamic	any suitable
:empty	VT_EMPTY	ignored
:null	VT_NULL	ignored
:short	VT_I2	integer
:long	VT_I4	integer
:float	VT_R4	single-float
:double	VT_R8	double-float
:cy	VT_CY
:date	VT_DATE
:bstr	VT_BSTR	string
:dispatch	VT_DISPATCH	FLI pointer
:error	VT_ERROR	ignored
:bool	VT_BOOL	nil or non nil
:variant	VT_VARIANT	FLI pointer
:unknown	VT_UNKNOWN	FLI pointer
:decimal	VT_DECIMAL
(:unsigned :char)	VT_UI1	integer
(:array . type)	VT_BYREF + VT code for type	array
:array or (:array array ) or (:array . types)	VT_ARRAY + VT_VARIANT	array
(:pointer type2)	VT_BYREF + VT code for type2	FLI pointer

If type is nil then the actual VT code is chosen dynamically according to the Lisp type of value (see Automation types, VT codes and their corresponding Lisp types).

If type is a cons of the form (:array . type) for some keyword type, then variant is set to contain an array of objects of type. Each element of value is expected to be suitable for conversion to type.

If type is :array or another list starting with :array then variant is set to contain an array of VARIANT objects with the same dimensions as value. Each element of value is converted as if by calling set-variant with a type chosen as follows:

• If type is the symbol :array, then nil is passed as the element type.
• If type is of the form (:array array) then array should be an array with the same dimensions as value. The element type is taken from the corresponding element of array.
• If type is of the form (:array . types) then types should be a suitable value for the :initial-contents argument to make-array to make an array of types with the same dimensions as value. The element type is taken from the corresponding element of that array. In particular, if value is a vector of length n then type should be a list of the form (:array type 1 type 2 ... type n ).

Examples

(set-variant v :null) (set-variant v :short 10) (set-variant v '(:pointer :short) ptr) (set-variant v '(:array :short :int) #(1 2))

See also

define-com-method