Newsgroups: comp.std.c++
Path: utzoo!censor!geac!alias!news
From: Reid Ellis <rae@utcs.toronto.edu>
Subject: Re: type/member tags (was Re: asking an object for its type)
Message-ID: <1991Mar1.150813.10737@alias.uucp>
Sender: Reid Ellis <rae%alias@csri.toronto.edu>
Reply-To: Reid Ellis <rae@utcs.toronto.edu>
Organization: Alias Research, Inc. Toronto ON Canada
References: <1991Feb19.214327.13930@gpu.utcs.utoronto.ca> 	<27C2D973.3C1B@tct.uucp> <DSOUZA.91Feb24173454@optima.cad.mcc.com> 	<27C95D3A.1715@tct.uucp> <DSOUZA.91Feb26130343@optima.cad.mcc.com>
Date: Fri, 1 Mar 91 15:08:13 GMT

Desmond Dsouza <dsouza@optima.cad.mcc.com> writes:
>Consider the proposed (now accepted) Exception Handling scheme for
>C++. The statement:
>  catch (ErrorClass& o) {
>	....
>  }
>is supposed to 'catch' a deeply nested call to:
>  throw ErrorClass("someError");
>
>Any implementation of this involves a run-time type check, including
>class derivation, on the object being thrown. Can you say 'Meta-class'?

This is simply overloading based on argument type.  Just like having
methods named "foo(Tbase &)" and "foo(Tderived &)".  No "Meta-class"
required.

					Reid
--
Reid Ellis  176 Brookbanks Drive, Toronto ON, M3A 2T5 Canada
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