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From: kipp@warp.sgi.com (Kipp Hickman)
Newsgroups: comp.lang.c++,comp.object
Subject: Re: Shippable C++ Objects (RFC)
Message-ID: <1542@odin.SGI.COM>
Date: 20 Nov 89 17:49:35 GMT
References: <31.UUL1.3#5109@pantor.UUCP> <CIMSHOP!DAVIDM.89Nov15101037@uunet.UU.NET>
Sender: news@odin.SGI.COM
Reply-To: kipp@warp.sgi.com (Kipp Hickman)
Organization: Silicon Graphics, Entry Systems Division
Lines: 24


To eliminate the ``switch'' implied by the object reconstruction mechanism,
all you need is a dictionary.  The key is the tag which identifies the object
in its byte stream form (a string works nicely).  The value is a pointer to
a function to perform the reconstruction.  Usually, the function is encode
thusly:

		void (*reader)(ObjectReader& source, void* where);

The "source" argument specifies the source of the byte stream, and provides
operations to retrieve data (could be a stream, for instance).   The "where"
argument provides an (optional) address where the object should be placed,
for the cases where the object is imbedded, and shouldn't allocate its
own memory.  In C++ 2.0, you implement the above function as follows:

		void FooReader(ObjectReader& source, void* where)
		{
			Foo* f = new(where) Foo(source);
		}

Lots of details left as an exercise to the reader... :-)

					kipp hickman
					silicon graphics inc.