Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c++
Subject: Re: Virtual functions and inline
Message-ID: <617@taumet.com>
Date: 1 Mar 91 17:03:54 GMT
References: <1991Feb28.141548.2043@cs.nott.ac.uk>
Organization: Taumetric Corporation, San Diego
Lines: 19

gas@cs.nott.ac.uk (Alan Shepherd) writes:

>Is it okay to declare virtual functions inline ? Even though the code
>to be excuted is substituted rather than a function call made, does
>the correct method still get called ?

It is okay to declare inline virtual functions.  The compiler will
instantiate (make a real copy of) the function and put its address
in the table of virtual functions for the class.  In general, it is
not possible to tell which version of a virtual function will be
called until run time, so there is no choice but to do this.

In some cases it can be determined at compile time that a particular
virtual function is being called, and a nice compiler will substitute
it inline.  Remember that "inline" is a "hint" to the compiler, and it
is not required to generate inline code for any function.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com