Path: utzoo!yunexus!ists!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!tut.cis.ohio-state.edu!pt.cs.cmu.edu!pt!dld From: dld@F.GP.CS.CMU.EDU (David Detlefs) Newsgroups: comp.lang.c++ Subject: Re: Shippable C++ Objects (RFC) Message-ID: Date: 17 Nov 89 19:43:45 GMT Article-I.D.: F.DLD.89Nov17144345 References: <31.UUL1.3#5109@pantor.UUCP> <4042@cadillac.CAD.MCC.COM> Followup-To: comp.lang.c++ Organization: CMU CS Department Lines: 23 In-reply-to: vaughan@mcc.com's message of 17 Nov 89 15:58:22 GMT Richard Sargent and Paul Vaughan, among others, have been having a discussion under this Subject, in which there is a shared assumption something like: When you ship an object across a network, the object needs to somehow contain information describing its type; otherwise, it cannot be reconstructed. I think this is a (somewhat) false assumption. Consider a strongly typed RPC interface. The sender must send the right type of object, or else type-checking would fail. The receiver knows the expected type of the RPC argument, and can use his knowledge of the type to construct (at compile-time) to reconstruct the object from the bit-stream. As David Brownell pointed out, all RPC systems solve this problem. Masterson's proposal goes farther in that it posits shipping the transitive pointer-closure of the object, while all RPC systems that I know about require objects with "in-line" data. -- Dave Detlefs Any correlation between my employer's opinion Carnegie-Mellon CS and my own is statistical rather than causal, dld@cs.cmu.edu except in those cases where I have helped to form my employer's opinion. (Null disclaimer.)