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XmtAssertWidgetClass(3)	   Library Functions Manual    XmtAssertWidgetClass(3)

NAME
       XmtAssertWidgetClass() -	verify the type	of a widget.

SYNOPSIS
       #include	<Xmt/Xmt.h>

       void XmtAssertWidgetClass(Widget	w, WidgetClass c, String procname)

ARGUMENTS
       INPUTS

	    w	   The widget to be checked.

	    c	   The desired widget class.

	    procname
		   An  identifying string to be	used in	the error message dis-
		   played if the widget	w is not of class c or a  subclass  of
		   it. This argument is	most useful when it is the name	of the
		   procedure that calls	XmtAssertWidgetClass().

DESCRIPTION
       XmtAssertWidgetClass() calls XtIsSubclass() to verify that widget w  is
       of  class  c  or	 is  a	subclass  of c.	If so, it returns and takes no
       action. If w is not of class c or  a  subclass,	then  XmtAssertWidget-
       Class()	prints	an  error message and calls the	function abort() which
       will cause the application to dump core and exit.

USAGE
       XmtAssertWidgetClass() is an analog to assert().	It is used  mainly  by
       widget  writers,	 but  also occasionally	by application programmers who
       are writing a function that expects a widget  argument  of  a  specific
       type.  Many  of	the  functions	in  the	Xmt library call this function
       internally.

       XmtAssertWidgetClass() is useful	 during	 the  process  of  application
       development  and	debugging because it gives a very clear	signal (a mes-
       sage and	a core dump with its associated	stack trace) of	when  applica-
       tion  code  is  calling	a function with	a bad widget argument. Once an
       application is debugged,	 you  can  compile  your  code	(and  the  Xmt
       library)	 with  the  -DNDEBUG  flag,  which  will  cause	 any  calls to
       XmtAssertWidgetClass() to be removed by the C preprocessor.

SEE ALSO
       Chapter 8, Utility Functions,
       abort(),	assert(), XtIsSubclass().

Xmt				  Motif	Tools	       XmtAssertWidgetClass(3)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | USAGE | SEE ALSO

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