lib.pointer Class

Namespace: lib

Pointer object compatible with C pointer

Description

MATLAB^® automatically converts arguments passed by reference to a function in an external library. A passed-by-reference argument in the function signature has type names ending with Ptr or PtrPtr. Use a pointer object instead of automatic conversion in the following situations.

• The function modifies data in an input argument.

• You are passing large amounts of data, and you want to control when MATLAB makes copies of the data.

• The library stores and uses the pointer, so you want the MATLAB function to control the lifetime of the lib.pointer object.

Creation

To create a lib.pointer object, use the MATLAB libpointer function.

A library function can return a lib.pointer object. Use the setdatatype method to convert the argument manually to use in MATLAB.

Properties

DataType — Type of pointer

character vector

Type of pointer, specified as a character vector, of any MATLAB numeric type, structure defined in the library, or enumeration defined in the library. For a list of valid MATLAB numeric types, refer to these tables in C and MATLAB Equivalent Types.

• MATLAB Primitive Types

• MATLAB Extended Types

Example: 'int16Ptr'

Attributes:

SetAccess	private
GetAccess	protected

Value — Value

any valid value

Value, specified as any valid value for given type.

Attributes:

SetAccess	private
GetAccess	protected

Methods

Public Methods

disp	Display lib.pointer type
isNull	Points to NULL pointer
plus	+ (plus) operator for pointer arithmetic
reshape	Reshape lib.pointer array
setdatatype	Initialize type and size of lib.pointer object

Examples

Create Pointer

Create a pointer pv of type int16 initialized to 485.

pv = libpointer('int16Ptr',485);

Display the properties of pv.

get(pv)

       Value: 485
    DataType: 'int16Ptr'

Version History

Introduced before R2006a