Path: utzoo!attcan!uunet!wuarchive!julius.cs.uiuc.edu!apple!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.mac.programmer
Subject: Re: C++/MacApp questions
Message-ID: <10486@goofy.Apple.COM>
Date: 27 Sep 90 23:47:52 GMT
References: <10594@pt.cs.cmu.edu>
Organization: Apple Computer, Inc.
Lines: 69

mkb@rover.ri.cmu.edu (Mike Blackwell) writes:

>Is there ANY way to speed things along besides turning on the RAM disk
>cache? It looks like most of the time is spent in CFront processing all
>those .h files. Will the dump/load mechanism work here, and if so, can you

There is a dump-load mechanism for C++.  But that version of C++ is
currently only available on the ETO CD-ROM.  The MacApp make files support
dump/load (for the MacApp headers) automatically.  

Another way to speed up compiles is to put the temporary files on a RAM
disk.  C++ really consists of 2 parts.  CFront converts the C++ code into C,
and the MPW C compiler compiles it.  Putting the intermediate file on a RAM
disk can make things go faster.  (Take a look at the CPlus script; I think
there is a shell variable that indicates where to put the temp files.)

>Why oh why can't I compile in the background? I have gobs of real memory,

MPW 3.x does compile in the background.  Another feature of C++ 3.1b4 is
that it will use MultiFinder temporary memory, which means you can set the
MPW Shell partition size to a smaller number (e.g. 2500-3000K) and still be
able to compile large programs when necessary.

This doesn't mean C++ will take less RAM.  It does mean that the available
RAM will be better utilized.  (If you aren't using C++, for example, the RAM
isn't premanently assigned to MPW.)

>A basic C++ question: I'd like to define some class specific constants
>inside the class - it makes sense, and develop_2 C++ style guide tells me
>it's a good idea. But how? The obvious way (to me) doesn't work:

There are 2 ways, depending on your situation:

(1) static data member:

class TFoo {
	static const short kMyConst;
...
};

In a .c file you need to write:

const TFoo::kMyConst = 42;

This is contant only in that C++ won't let you change it.  The compiler
won't be able to evaluate it at compile-time, in most (if not all) cases.

(2) use an enum:

class TBar {
	enum {kMyConst=42};
...
};

This will be a constant constant.  You can also give the enum a type name,
and use that type.  You would refer to the type as TBar::<typename>.  



-- 
		 Larry Rosenstein,  Object Specialist
 Apple Computer, Inc.  20525 Mariani Ave, MS 46-B  Cupertino, CA 95014
	    AppleLink:Rosenstein1    domain:lsr@Apple.COM
		UUCP:{sun,voder,nsc,decwrl}!apple!lsr
-- 
		 Larry Rosenstein,  Object Specialist
 Apple Computer, Inc.  20525 Mariani Ave, MS 46-B  Cupertino, CA 95014
	    AppleLink:Rosenstein1    domain:lsr@Apple.COM
		UUCP:{sun,voder,nsc,decwrl}!apple!lsr