Re: c++/10307: constructor for static object of template omitted

[Wolfgang Bangerth <bangerth@ices.utexas.edu>]

The following reply was made to PR c++/10307; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ices.utexas.edu>
To: gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c++/10307: constructor for static object of template omitted
Date: Fri, 4 Apr 2003 14:12:44 -0600 (CST)

 ---------- Forwarded message ----------
 Date: Thu, 3 Apr 2003 23:11:31 -0500
 From: Douglas Kilpatrick <kilpatds@oppositelock.org>
 To: bangerth@dealii.org
 Subject: Re: c++/10307: constructor for static object of template omitted
 
 On 3 Apr 2003 22:23:55 -0000
 bangerth@dealii.org wrote:
 
 >     I think this is actually what the standard prescribes,
 >     since static variables are only instantiated by use or
 >     by explicit instantiation, not by instantiation of
 >     the class they belong to. In fact, you can make the above
 >     code work as you expect it by adding this line:
 >       template TemplateStatic Template<int>::s;
 
 Ok.  Question for you then...
 
 The actual place I ran into this was a plugin framework, trying to
 eliminate some of the cookie-cutter code.
 
 I have a base class that is the plugin interface.  I want to create a
 intermediate class that the user of the framework subclasses that handles
 registering the plugin and factory method on library load (dlopen()).
 Then the user subclasses from that.
 
 I would have though that a subclass of a template by a non-template would
 cause the template to be instantiated, but it doesn't seem to.  I have to
 declare an explicit variable of the non-template class to get things to
 work.
 
 What's the syntax for forcing that without actually declaring a variable? 
 Its not a template, so using the explicit template instantation syntax
 doesn't work.  (Code freely available if you want it.  ~6k)
 
 Or is this simply a case of "Don't Do That Then."? :)
 
 Doug
 -- 
 Doug Kilpatrick
 kilpatds@oppositelock.org