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From: gv9b2c9z@umiami.ir.miami.edu (Ordinary Man)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Question About NewPtr...
Message-ID: <1991Jan25.111038.7671@umiami.ir.miami.edu>
Date: 25 Jan 91 16:10:37 GMT
References: <1991Jan25.002913.7668@umiami.ir.miami.edu>
Organization: Univ of Miami IR
Lines: 47

In article <1991Jan25.002913.7668@umiami.ir.miami.edu>, ian@umiami.ir.miami.edu writes:
> ...the information about NewPtr wasn't very specific...it says that NewPtr returns
> a Ptr....I tried replacing all of my mallocs with NewPtr but now I get a
> compile error saying that the varible and the Ptr returned by NewPtr aren't
> the same...I'm not sure what I'm doing wrong...the varible I'm trying to set
> is of type 
> SomeRecord    *gAPointer;
> could anyone help me out....Thanx 
> -- 
> Scruffy
> Ian Sullivan

Whenever you allocate memory with the memory manager routine NewPtr, it returns
a generic pointer of type Ptr. If you wish to use this allocation in your
program, and your pointer is of a different type than Ptr, you must typecast,
and use that pointer instead. For example in PASCAL, you would say:

	type
		myData=whateverType;
		aPointer=^myData;

var
	thisPtr:aPointer;

begin
	....
	thisPtr:=aPointer(NewPtr(sizeof(myData)));
	....
Now you can use this pointer anywhere you wish. But remeber that the memory
manager routines expect the generic pointer as a parameter so you must say:

	....
	DisposPtr(Ptr(thisPtr));
	...
when you dispose of your pointer.
Hope this helps,
		==Dan

-- 
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