Object::guard

Section: ET++ method description (n)
Updated: automatically Fri Mar 1 10:54:57 1991
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NAME

Object::guard - instance method

TEMPLATE

checkedPointer = ObjPtr guard(Class * class)

SPECIFIERS

public

DESCRIPTION

Checks whether this object is an instance of the class. If this is the case, then it returns the receiver, otherwise an error (category error) is issued, and the return value is nil.
This method is usually not directly called. The macro Guard is the interface for this method, since the macro's value has the static type of (<class> *). Thus, the client does not need to cast the expresson. See also macro IsKindOf.
This method and therefore the macro Guard and the macro IsKindOf require that class descriptors are properly set up .
See also technote Metaclasses.

ARGUMENTS

Class * class: the class descriptor of the class which the receiver shall be instance of.
Class descriptors may be literally denoted with the macro Meta. For example, Meta(Window) if the desired class is Window.

RETURN ARGUMENT

ObjPtr checkedPointer

FILES

implementation:: Object.C

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Time: 00:40:25 GMT, March 30, 2022