--- gvpe/src/callback.pl	2003/10/16 02:41:21	1.2
+++ gvpe/src/callback.pl	2007/12/02 00:54:52	1.10
@@ -1,18 +1,19 @@
 #!/usr/bin/perl
 
+use strict;
+
 print <<EOF;
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
-// THIS IS A GENERATED FILE, RUN callback.pl to regenerate it
+// THIS IS A GENERATED FILE: RUN callback.pl to regenerate it
+// THIS IS A GENERATED FILE: callback.pl is part of the GVPE
+// THIS IS A GENERATED FILE: distribution.
 
 /*
     callback.h -- C++ callback mechanism
-    Copyright (C) 2003 Marc Lehmann <pcg\@goof.com>
+    Copyright (C) 2003-2007 Marc Lehmann <pcg\@goof.com>
  
-    This program is free software; you can redistribute it and/or modify
+    This file is part of GVPE.
+
+    GVPE is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
@@ -23,71 +24,105 @@
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+    along with gvpe; if not, write to the Free Software
+    Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#ifndef VPE_CALLBACK_H__
-#define VPE_CALLBACK_H__
+#ifndef CALLBACK_H__
+#define CALLBACK_H__
+
+#define CALLBACK_H_VERSION 3
+
+template<class signature>
+struct callback_funtype_trait;
+
+template<int arity, class signature>
+struct callback_get_impl;
 
 EOF
 
-for my $a (0..7) {
+for my $a (0..10) {
    my $CLASS     = join "", map ", class A$_", 1..$a;
    my $TYPE      = join ", ", map "A$_", 1..$a;
    my $ARG       = join ", ", map "a$_", 1..$a;
    my $TYPEARG   = join ", ", map "A$_ a$_", 1..$a;
-   my $_ARG      = $ARG     ? ", $ARG"     : "";
-   my $_TYPEARG  = $TYPEARG ? ", $TYPEARG" : "";
+   my $TYPEDEFS  = join " ", map "typedef A$_ arg$_\_type;", 1..$a;
+   my $TYPEvoid  = $TYPE    ? $TYPE        : "void";
+   my $_TYPE     = $TYPE    ? ", $TYPE"    : "";
+   my $_TTYPE    = $a       ? join "", map ", typename T::arg$_\_type", 1..$a : "";
    
    print <<EOF;
 template<class R$CLASS>
-class callback$a {
-  struct object { };
+class callback$a
+{
+  struct klass; // it is vital that this is never defined
 
-  void *obj;
-  R (object::*meth)($TYPE);
+  typedef R (klass::*ptr_type)($TYPE);
 
-  /* a proxy is a kind of recipe on how to call a specific class method	*/
-  struct proxy_base {
-    virtual R call (void *obj, R (object::*meth)($TYPE)$_TYPEARG) = 0;
-  };
-  template<class O1, class O2>
-  struct proxy : proxy_base {
-    virtual R call (void *obj, R (object::*meth)($TYPE)$_TYPEARG)
-      {
-        ((reinterpret_cast<O1 *>(obj)) ->* (reinterpret_cast<R (O2::*)($TYPE)>(meth)))
-          ($ARG);
-      }
-  };
-
-  proxy_base *prxy;
+  klass *o;
+  R (klass::*m)($TYPE);
 
 public:
   template<class O1, class O2>
-  callback$a (O1 *object, R (O2::*method)($TYPE))
-    {
-      static proxy<O1,O2> p;
-      obj  = reinterpret_cast<void *>(object);
-      meth = reinterpret_cast<R (object::*)($TYPE)>(method);
-      prxy = &p;
-    }
-
+  explicit callback$a (O1 *object, R (O2::*method)($TYPE))
+  {
+    o = reinterpret_cast<klass *>(object);
+    m = reinterpret_cast<R (klass::*)($TYPE)>(method);
+  }
+
+  // this works because a standards-compliant C++ compiler
+  // basically can't help it: it doesn't have the knowledge
+  // required to miscompile (klass is not defined anywhere
+  // and nothing is known about the constructor arguments) :)
   R call($TYPEARG) const
-    {
-      return prxy->call (obj, meth$_ARG);
-    }
+  {
+    return (o->*m) ($ARG);
+  }
 
   R operator ()($TYPEARG) const
-    {
-      return call ($ARG);
-    }
+  {
+    return call ($ARG);
+  }
 };
 
+template<class R$CLASS>
+struct callback_funtype_trait$a
+{
+  static const int arity = $a;
+  typedef R type ($TYPEvoid);
+  typedef R result_type;
+  $TYPEDEFS
+};
+
+template<class R$CLASS>
+struct callback_funtype_trait<R ($TYPE)> : callback_funtype_trait$a<R$_TYPE>
+{
+};
+
+template<class signature>
+struct callback_get_impl<$a, signature>
+{
+  typedef callback_funtype_trait<signature> T;
+  typedef callback$a<typename T::result_type$_TTYPE> type;
+};
+   
 EOF
 }
 
 print <<EOF
+
+template<class signature>
+struct callback : callback_get_impl<callback_funtype_trait<signature>::arity, signature>::type
+{
+  typedef typename callback_get_impl<callback_funtype_trait<signature>::arity, signature>::type base_type;
+
+  template<class O, class M>
+  explicit callback (O object, M method)
+  : base_type (object, method)
+  {
+  }
+};
+
 #endif
 EOF