c++/9278: dependent type in conversion operator bug

[Wolfgang Bangerth]

The following reply was made to PR c++/9278; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: David Abrahams <dave@boost-consulting.com>
Cc: "Joseph S. Myers" <jsm28@cam.ac.uk>, <gcc-bugs@gcc.gnu.org>,
   <gcc-gnats@gcc.gnu.org>
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/