The IDL_Object class is designed to be inherited by objects that define _overload methods, in order to overload the behavior of one or more of IDL’s standard operators. It is not meant to be instantiated directly.

To overload the behavior of a standard operator for objects of a user-defined object class, you would write an overloaded operator method for the class, and add IDL_Object as a superclass of the class. Object classes that do not inherit from the IDL_Object class do not use operator overload methods even if the methods are defined.

Object classes that inherit from the IDL_Object class can also overload several routines that provide information about variables: HELP, PRINT, and SIZE.

Note: The INIT and CLEANUP methods for a subclass do not need to call this superclass' INIT and CLEANUP methods.

Superclasses

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None

Creation

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This class serves as an interface class for other classes. There is never a need to instantiate an IDL_Object class directly.

Properties

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DIM

LENGTH

NDIM

TNAME

TYPECODE

TYPENAME

See IDL Object Properties for details.

Methods

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This class defines methods for each standard IDL operator that can be overloaded.

This class has the following methods:

• IDL_Object::GetProperty
• IDL_Object::_overloadAND
• IDL_Object::_overloadAsterisk
• IDL_Object::_overloadBracketsLeftSide
• IDL_Object::_overloadBracketsRightSide
• IDL_Object::_overloadCaret
• IDL_Object::_overloadEQ
• IDL_Object::_overloadForeach
• IDL_Object::_overloadFunction
• IDL_Object::_overloadGE
• IDL_Object::_overloadGreaterThan
• IDL_Object::_overloadGT
• IDL_Object::_overloadHelp
• IDL_Object::_overloadImpliedPrint
• IDL_Object::_overloadIsTrue
• IDL_Object::_overloadLE
• IDL_Object::_overloadLessThan
• IDL_Object::_overloadLT
• IDL_Object::_overloadMethod
• IDL_Object::_overloadMinus
• IDL_Object::_overloadMinusMinus
• IDL_Object::_overloadMinusUnary
• IDL_Object::_overloadMOD
• IDL_Object::_overloadNE
• IDL_Object::_overloadNOT
• IDL_Object::_overloadOR
• IDL_Object::_overloadPlus
• IDL_Object::_overloadPlusPlus
• IDL_Object::_overloadPostIncrementCopy
• IDL_Object::_overloadPound
• IDL_Object::_overloadPoundPound
• IDL_Object::_overloadPrint
• IDL_Object::_overloadSize
• IDL_Object::_overloadSlash
• IDL_Object::_overloadTilde
• IDL_Object::_overloadXOR

Example

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A user-defined class that overloads one or more operators must include the INHERITS token in the class structure definition:

PRO myObjectClass__define

structure = { myObjectClass, $

              PROPERTY1: 0L, $

              PROPERTY2: '', $

              INHERITS IDL_Object $

            }

END

Version History

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8.0	Introduced
8.3	Added ::_overloadImpliedPrint
8.4	Added ::GetProperty method with Variable Attributes
8.4.1	Added ::_overloadPlusPlus, ::_overloadMinusMinus, ::_overloadPostIncrementCopy
8.5	Added ::_overloadFunction and ::_overloadMethod

See Also

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