From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19838 invoked by alias); 14 Jan 2003 00:36:00 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 19824 invoked by uid 71); 14 Jan 2003 00:36:00 -0000 Date: Tue, 14 Jan 2003 00:36:00 -0000 Message-ID: <20030114003600.19823.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Wolfgang Bangerth Subject: Re: c++/9278: dependent type in conversion operator bug Reply-To: Wolfgang Bangerth X-SW-Source: 2003-01/txt/msg00850.txt.bz2 List-Id: The following reply was made to PR c++/9278; it has been noted by GNATS. From: Wolfgang Bangerth To: David Abrahams Cc: "Joseph S. Myers" , , Subject: Re: c++/9278: dependent type in conversion operator bug Date: Mon, 13 Jan 2003 18:27:36 -0600 (CST) > > Indeed a very obscure feature. (Although, I must admit that, I desperately > > needed something like that not too long ago and had to invent various > > template metaprogramming hoops to work around...) > > I needed exactly that yesterday, which is why it came up ;-) > Using SFINAE to rule out certain conversions was my game, but it > didn't fly :( SFINAE??? In my case, I wanted to make things more uniform in Functor classes: when you call a function, it either returns a value, or void. So this does not go together RETTYPE ret_val = function(args) if RETTYPE==void. What an annoying difference, and how convenient would it be if there were "void variables", i.e. objects to which you can assign the result of a void expression :-) Some template trickery and specilization can get one around this, however. W. ------------------------------------------------------------------------- Wolfgang Bangerth email: bangerth@ticam.utexas.edu www: http://www.ticam.utexas.edu/~bangerth/