From 08d37987224d023cc937d19a4fcff62ad00f43c9 Mon Sep 17 00:00:00 2001
From: Dave Abrahams <dave@boostpro.com>
Date: Fri, 2 Jan 2004 18:34:17 +0000
Subject: [PATCH] .

[SVN r21449]
---
 todo.html | 143 ++++++++++++++++++++++++++++++++++--------------------
 todo.txt  |  67 +++++++++++++++++--------
 2 files changed, 138 insertions(+), 72 deletions(-)
diff --git a/todo.html b/todo.html
index b2095ab6..aea022dc 100755
--- a/todo.html
+++ b/todo.html
@@ -3,7 +3,7 @@
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
-<meta name="generator" content="Docutils 0.3.0: http://docutils.sourceforge.net/" />
+<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
 <title>Boost.Python TODO list Boost</title>
 <link rel="stylesheet" href="../../rst.css" type="text/css" />
 </head>
@@ -15,8 +15,10 @@
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
-<tr class="field"><th class="field-name">copyright:</th><td class="field-body">Copyright David Abrahams 2003. See accompanying
-<a class="reference" href="../../LICENSE_1_0.txt">license</a> for terms of use.</td>
+<tr class="field"><th class="field-name">copyright:</th><td class="field-body">Copyright David Abrahams 2003. Use, modification, and
+distribution are subject to the Boost Software License, Version
+1.0. (See accompanying file <a class="reference" href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy at
+<a class="reference" href="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</td>
 </tr>
 </tbody>
 </table>
@@ -27,30 +29,36 @@
 <li><a class="reference" href="#base-class-for-virtual-function-callback-wrappers" id="id5" name="id5">Base Class for Virtual Function Callback Wrappers</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#functions" id="id6" name="id6">Functions</a><ul>
-<li><a class="reference" href="#wrapping-function-objects" id="id7" name="id7">Wrapping Function Objects</a></li>
-<li><a class="reference" href="#best-match-overload-resolution" id="id8" name="id8">&quot;Best Match&quot; Overload Resolution</a></li>
-<li><a class="reference" href="#injected-constructors" id="id9" name="id9">Injected Constructors</a></li>
+<li><a class="reference" href="#miscellaneous" id="id6" name="id6">Miscellaneous</a><ul>
+<li><a class="reference" href="#support-for-enums-with-duplicate-values" id="id7" name="id7">Support for Enums with Duplicate Values</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#type-converters" id="id10" name="id10">Type Converters</a><ul>
-<li><a class="reference" href="#lvalue-conversions-from-non-const-pytypeobject-s" id="id11" name="id11">Lvalue conversions from non-const <tt class="literal"><span class="pre">PyTypeObject*</span></tt>s</a></li>
-<li><a class="reference" href="#converter-scoping" id="id12" name="id12">Converter Scoping</a></li>
-<li><a class="reference" href="#file-conversions" id="id13" name="id13"><tt class="literal"><span class="pre">FILE*</span> <span class="pre">conversions</span></tt></a></li>
-<li><a class="reference" href="#post-call-actions" id="id14" name="id14">Post-Call Actions</a></li>
-<li><a class="reference" href="#pyunicode-support" id="id15" name="id15"><tt class="literal"><span class="pre">PyUnicode</span></tt> Support</a></li>
+<li><a class="reference" href="#functions" id="id8" name="id8">Functions</a><ul>
+<li><a class="reference" href="#wrapping-function-objects" id="id9" name="id9">Wrapping Function Objects</a></li>
+<li><a class="reference" href="#best-match-overload-resolution" id="id10" name="id10">&quot;Best Match&quot; Overload Resolution</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#documentation" id="id16" name="id16">Documentation</a><ul>
-<li><a class="reference" href="#builtin-converters" id="id17" name="id17">Builtin Converters</a></li>
-<li><a class="reference" href="#internals" id="id18" name="id18">Internals</a></li>
+<li><a class="reference" href="#type-converters" id="id11" name="id11">Type Converters</a><ul>
+<li><a class="reference" href="#lvalue-conversions-from-non-const-pytypeobject-s" id="id12" name="id12">Lvalue conversions from non-const <tt class="literal"><span class="pre">PyTypeObject*</span></tt>s</a></li>
+<li><a class="reference" href="#converter-scoping" id="id13" name="id13">Converter Scoping</a></li>
+<li><a class="reference" href="#file-conversions" id="id14" name="id14"><tt class="literal"><span class="pre">FILE*</span></tt> conversions</a></li>
+<li><a class="reference" href="#void-conversions" id="id15" name="id15"><tt class="literal"><span class="pre">void*</span></tt> conversions</a></li>
+<li><a class="reference" href="#post-call-actions" id="id16" name="id16">Post-Call Actions</a></li>
+<li><a class="reference" href="#pyunicode-support" id="id17" name="id17"><tt class="literal"><span class="pre">PyUnicode</span></tt> Support</a></li>
+<li><a class="reference" href="#ownership-metadata" id="id18" name="id18">Ownership Metadata</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#large-scale" id="id19" name="id19">Large Scale</a><ul>
-<li><a class="reference" href="#langbinding" id="id20" name="id20">Langbinding</a></li>
-<li><a class="reference" href="#refactoring-and-reorganization" id="id21" name="id21">Refactoring and Reorganization</a></li>
-<li><a class="reference" href="#numarray-support-enhancements" id="id22" name="id22">NumArray Support Enhancements</a></li>
-<li><a class="reference" href="#pyfinalize-safety" id="id23" name="id23"><tt class="literal"><span class="pre">PyFinalize</span></tt> Safety</a></li>
+<li><a class="reference" href="#documentation" id="id19" name="id19">Documentation</a><ul>
+<li><a class="reference" href="#builtin-converters" id="id20" name="id20">Builtin Converters</a></li>
+<li><a class="reference" href="#internals" id="id21" name="id21">Internals</a></li>
+</ul>
+</li>
+<li><a class="reference" href="#large-scale" id="id22" name="id22">Large Scale</a><ul>
+<li><a class="reference" href="#full-threading-support" id="id23" name="id23">Full Threading Support</a></li>
+<li><a class="reference" href="#langbinding" id="id24" name="id24">Langbinding</a></li>
+<li><a class="reference" href="#refactoring-and-reorganization" id="id25" name="id25">Refactoring and Reorganization</a></li>
+<li><a class="reference" href="#numarray-support-enhancements" id="id26" name="id26">NumArray Support Enhancements</a></li>
+<li><a class="reference" href="#pyfinalize-safety" id="id27" name="id27"><tt class="literal"><span class="pre">PyFinalize</span></tt> Safety</a></li>
 </ul>
 </li>
 </ul>
@@ -65,13 +73,27 @@
 <li><a class="reference" href="http://mail.python.org/pipermail/c++-sig/2003-August/005297.html">http://mail.python.org/pipermail/c++-sig/2003-August/005297.html</a>
 (search for <tt class="literal"><span class="pre">VirtualDispatcher</span></tt>) describes how callback classes
 can swap ownership relationship with their Python wrappers.</li>
+<li><a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301">http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301</a>
+describes how this can also be used to considerably simplify
+callback classes, solve some &quot;dangling reference&quot; problems, and
+optimize the calling of non-overridden virtual functions.</li>
 </ul>
 </div>
 </div>
+<div class="section" id="miscellaneous">
+<h1><a class="toc-backref" href="#id6" name="miscellaneous">Miscellaneous</a></h1>
+<div class="section" id="support-for-enums-with-duplicate-values">
+<h2><a class="toc-backref" href="#id7" name="support-for-enums-with-duplicate-values">Support for Enums with Duplicate Values</a></h2>
+<blockquote>
+Scott Snyder provided a patch; Dave was dissatisfied for some
+reason, but maybe it should just be applied if no further action
+occurs <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/1824616">http://aspn.activestate.com/ASPN/Mail/Message/1824616</a>.</blockquote>
+</div>
+</div>
 <div class="section" id="functions">
-<h1><a class="toc-backref" href="#id6" name="functions">Functions</a></h1>
+<h1><a class="toc-backref" href="#id8" name="functions">Functions</a></h1>
 <div class="section" id="wrapping-function-objects">
-<h2><a class="toc-backref" href="#id7" name="wrapping-function-objects">Wrapping Function Objects</a></h2>
+<h2><a class="toc-backref" href="#id9" name="wrapping-function-objects">Wrapping Function Objects</a></h2>
 <blockquote>
 <p>It should be possible to wrap classes which support <tt class="literal"><span class="pre">operator()</span></tt>
 as Python methods.</p>
@@ -79,7 +101,7 @@ as Python methods.</p>
 </blockquote>
 </div>
 <div class="section" id="best-match-overload-resolution">
-<h2><a class="toc-backref" href="#id8" name="best-match-overload-resolution">&quot;Best Match&quot; Overload Resolution</a></h2>
+<h2><a class="toc-backref" href="#id10" name="best-match-overload-resolution">&quot;Best Match&quot; Overload Resolution</a></h2>
 <blockquote>
 <p>Overload resolution currently depends on the order in which <tt class="literal"><span class="pre">def</span></tt>
 calls are made (preferring later overloads).  This should be
@@ -88,29 +110,16 @@ This may await <a class="reference" href="#langbinding">Langbinding</a> integrat
 already in <a class="reference" href="http://luabind.sf.net">Luabind</a>.</p>
 </blockquote>
 </div>
-<div class="section" id="injected-constructors">
-<h2><a class="toc-backref" href="#id9" name="injected-constructors">Injected Constructors</a></h2>
-<blockquote>
-<p>Enabling the addition of new constructor functors or factory
-constructors which aren't in the underlying C++ interface.
-Interface still to be decided.  Here is a discussion of it:</p>
-<blockquote>
-<a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/1744280">http://aspn.activestate.com/ASPN/Mail/Message/1744280</a></blockquote>
-<p>However, I'm pretty sure we can't use the init&lt;&gt;(f) interface here
-because it will have to instantiate the code for the wrapped
-class' default constructor, which may not exist.</p>
-</blockquote>
-</div>
 </div>
 <div class="section" id="type-converters">
-<h1><a class="toc-backref" href="#id10" name="type-converters">Type Converters</a></h1>
+<h1><a class="toc-backref" href="#id11" name="type-converters">Type Converters</a></h1>
 <div class="section" id="lvalue-conversions-from-non-const-pytypeobject-s">
-<h2><a class="toc-backref" href="#id11" name="lvalue-conversions-from-non-const-pytypeobject-s">Lvalue conversions from non-const <tt class="literal"><span class="pre">PyTypeObject*</span></tt>s</a></h2>
+<h2><a class="toc-backref" href="#id12" name="lvalue-conversions-from-non-const-pytypeobject-s">Lvalue conversions from non-const <tt class="literal"><span class="pre">PyTypeObject*</span></tt>s</a></h2>
 <blockquote>
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1662717">http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1662717</a></blockquote>
 </div>
 <div class="section" id="converter-scoping">
-<h2><a class="toc-backref" href="#id12" name="converter-scoping">Converter Scoping</a></h2>
+<h2><a class="toc-backref" href="#id13" name="converter-scoping">Converter Scoping</a></h2>
 <blockquote>
 <p><a class="reference" href="http://article.gmane.org/gmane.comp.python.c++/2044">http://article.gmane.org/gmane.comp.python.c++/2044</a></p>
 <p>If this gets done at all, it is going to happen in conjunction
@@ -118,12 +127,18 @@ with <a class="reference" href="#langbinding">Luabind integration</a>.</p>
 </blockquote>
 </div>
 <div class="section" id="file-conversions">
-<h2><a class="toc-backref" href="#id13" name="file-conversions"><tt class="literal"><span class="pre">FILE*</span> <span class="pre">conversions</span></tt></a></h2>
+<h2><a class="toc-backref" href="#id14" name="file-conversions"><tt class="literal"><span class="pre">FILE*</span></tt> conversions</a></h2>
 <blockquote>
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/1411366">http://aspn.activestate.com/ASPN/Mail/Message/1411366</a></blockquote>
 </div>
+<div class="section" id="void-conversions">
+<h2><a class="toc-backref" href="#id15" name="void-conversions"><tt class="literal"><span class="pre">void*</span></tt> conversions</a></h2>
+<blockquote>
+Pointers to <em>cv</em> <tt class="literal"><span class="pre">void</span></tt> should be able to be passed and
+returned as opaque values.</blockquote>
+</div>
 <div class="section" id="post-call-actions">
-<h2><a class="toc-backref" href="#id14" name="post-call-actions">Post-Call Actions</a></h2>
+<h2><a class="toc-backref" href="#id16" name="post-call-actions">Post-Call Actions</a></h2>
 <blockquote>
 From-Python converters should be passed an extra reference to a
 chain of post-call actions in the Policies object, where they can
@@ -131,23 +146,34 @@ register an additional action.  See the end of
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1755435">http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1755435</a></blockquote>
 </div>
 <div class="section" id="pyunicode-support">
-<h2><a class="toc-backref" href="#id15" name="pyunicode-support"><tt class="literal"><span class="pre">PyUnicode</span></tt> Support</a></h2>
+<h2><a class="toc-backref" href="#id17" name="pyunicode-support"><tt class="literal"><span class="pre">PyUnicode</span></tt> Support</a></h2>
 <blockquote>
 <p>Review and possibly incorporate changes from <a class="reference" href="mailto:qinlj-at-solidshare.com">Lijun Qin</a> at
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1771145">http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1771145</a></p>
 </blockquote>
 </div>
+<div class="section" id="ownership-metadata">
+<h2><a class="toc-backref" href="#id18" name="ownership-metadata">Ownership Metadata</a></h2>
+<blockquote>
+In the thread at
+<a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301">http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301</a>,
+Niall Douglas describes an idea for solving some &quot;false&quot;
+dangling pointer/reference return errors by attaching data about
+objects which lets the framework determine that the reference
+count on an object doesn't tell us anything about the lifetime
+of its data.</blockquote>
+</div>
 </div>
 <div class="section" id="documentation">
-<h1><a class="toc-backref" href="#id16" name="documentation">Documentation</a></h1>
+<h1><a class="toc-backref" href="#id19" name="documentation">Documentation</a></h1>
 <div class="section" id="builtin-converters">
-<h2><a class="toc-backref" href="#id17" name="builtin-converters">Builtin Converters</a></h2>
+<h2><a class="toc-backref" href="#id20" name="builtin-converters">Builtin Converters</a></h2>
 <blockquote>
 Builtin correspondences between builtiin Python types and C++
 types need to be documented</blockquote>
 </div>
 <div class="section" id="internals">
-<h2><a class="toc-backref" href="#id18" name="internals">Internals</a></h2>
+<h2><a class="toc-backref" href="#id21" name="internals">Internals</a></h2>
 <blockquote>
 <p>The structure of the framework needs to get documented; <a class="reference" href="mailto:brett.calcott-at-paradise.net.nz">Brett
 Calcott</a> has promised to turn <a class="reference" href="doc/internals.html">this document</a> into something fit
@@ -156,27 +182,38 @@ for users</p>
 </div>
 </div>
 <div class="section" id="large-scale">
-<h1><a class="toc-backref" href="#id19" name="large-scale">Large Scale</a></h1>
+<h1><a class="toc-backref" href="#id22" name="large-scale">Large Scale</a></h1>
+<div class="section" id="full-threading-support">
+<h2><a class="toc-backref" href="#id23" name="full-threading-support">Full Threading Support</a></h2>
+<blockquote>
+Various people have proposed patches to improve threading support
+in Boost.Python: see the thread at
+<a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/1826544">http://aspn.activestate.com/ASPN/Mail/Message/1826544</a> and
+<a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/1865842">http://aspn.activestate.com/ASPN/Mail/Message/1865842</a> for some
+examples.  The only problem is that these are incomplete
+solutions and verifying that we <em>do</em> have a complete solution is
+going to take some time and attention.</blockquote>
+</div>
 <div class="section" id="langbinding">
-<h2><a class="toc-backref" href="#id20" name="langbinding">Langbinding</a></h2>
+<h2><a class="toc-backref" href="#id24" name="langbinding">Langbinding</a></h2>
 <blockquote>
 This project to generalizes Boost.Python to work for other
 languages, initially Lua.  See discussions at
 <a class="reference" href="http://lists.sourceforge.net/lists/listinfo/boost-langbinding">http://lists.sourceforge.net/lists/listinfo/boost-langbinding</a></blockquote>
 </div>
 <div class="section" id="refactoring-and-reorganization">
-<h2><a class="toc-backref" href="#id21" name="refactoring-and-reorganization">Refactoring and Reorganization</a></h2>
+<h2><a class="toc-backref" href="#id25" name="refactoring-and-reorganization">Refactoring and Reorganization</a></h2>
 <blockquote>
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1673338">http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1673338</a></blockquote>
 </div>
 <div class="section" id="numarray-support-enhancements">
-<h2><a class="toc-backref" href="#id22" name="numarray-support-enhancements">NumArray Support Enhancements</a></h2>
+<h2><a class="toc-backref" href="#id26" name="numarray-support-enhancements">NumArray Support Enhancements</a></h2>
 <blockquote>
 Consider integrating the enhancements described in
 <a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1757092">http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1757092</a></blockquote>
 </div>
 <div class="section" id="pyfinalize-safety">
-<h2><a class="toc-backref" href="#id23" name="pyfinalize-safety"><tt class="literal"><span class="pre">PyFinalize</span></tt> Safety</a></h2>
+<h2><a class="toc-backref" href="#id27" name="pyfinalize-safety"><tt class="literal"><span class="pre">PyFinalize</span></tt> Safety</a></h2>
 <blockquote>
 <p>Currently Boost.Python has several global (or function-static)
 objects whose existence keeps reference counts from dropping to
@@ -191,10 +228,10 @@ interpreter.  <a class="reference" href="mailto:dirk-at-gerrits.homeip.net">Dirk
 </div>
 </div>
 </div>
-<hr class="footer"/>
+<hr class="footer" />
 <div class="footer">
 <a class="reference" href="todo.txt">View document source</a>.
-Generated on: 2003-09-11 11:04 UTC.
+Generated on: 2004-01-02 18:33 UTC.
 Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 </div>
 </body>
diff --git a/todo.txt b/todo.txt
index be4e329f..01477258 100644
--- a/todo.txt
+++ b/todo.txt
@@ -11,12 +11,14 @@ __ ../../index.htm
 
 .. _`Boost.Python`: index.html
 
-:copyright: Copyright David Abrahams 2003. See accompanying
-            license_ for terms of use.
+:copyright: Copyright David Abrahams 2003. Use, modification, and
+    distribution are subject to the Boost Software License, Version
+    1.0. (See accompanying file `LICENSE_1_0.txt`_ or copy at
+    http://www.boost.org/LICENSE_1_0.txt) 
 
 .. contents:: Outline
 
-.. _license: ../../LICENSE_1_0.txt
+.. _`LICENSE_1_0.txt`: ../../LICENSE_1_0.txt
 
 Class Support
 =============
@@ -31,6 +33,20 @@ Base Class for Virtual Function Callback Wrappers
   (search for ``VirtualDispatcher``) describes how callback classes
   can swap ownership relationship with their Python wrappers.
 
+* http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301
+  describes how this can also be used to considerably simplify
+  callback classes, solve some "dangling reference" problems, and
+  optimize the calling of non-overridden virtual functions.
+
+Miscellaneous
+=============
+
+Support for Enums with Duplicate Values
+---------------------------------------
+
+  Scott Snyder provided a patch; Dave was dissatisfied for some
+  reason, but maybe it should just be applied if no further action
+  occurs http://aspn.activestate.com/ASPN/Mail/Message/1824616.
 
 
 Functions
@@ -56,21 +72,6 @@ Wrapping Function Objects
 
   .. _Luabind: http://luabind.sf.net
 
-Injected Constructors
----------------------
-
-  Enabling the addition of new constructor functors or factory
-  constructors which aren't in the underlying C++ interface.
-  Interface still to be decided.  Here is a discussion of it:
-
-    http://aspn.activestate.com/ASPN/Mail/Message/1744280
-
-  However, I'm pretty sure we can't use the init<>(f) interface here
-  because it will have to instantiate the code for the wrapped
-  class' default constructor, which may not exist.
-
-
-
 Type Converters
 ===============
 
@@ -89,11 +90,17 @@ Converter Scoping
 
   __ Langbinding_
 
-``FILE* conversions``
+``FILE*`` conversions
 ---------------------
 
   http://aspn.activestate.com/ASPN/Mail/Message/1411366
 
+``void*`` conversions
+---------------------
+
+  Pointers to *cv* ``void`` should be able to be passed and
+  returned as opaque values.
+
 Post-Call Actions
 -----------------
 
@@ -110,6 +117,17 @@ Post-Call Actions
 
   .. _`Lijun Qin`: mailto:qinlj-at-solidshare.com
 
+Ownership Metadata
+------------------
+
+  In the thread at
+  http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301,
+  Niall Douglas describes an idea for solving some "false"
+  dangling pointer/reference return errors by attaching data about
+  objects which lets the framework determine that the reference
+  count on an object doesn't tell us anything about the lifetime
+  of its data.
+
 Documentation
 =============
 
@@ -134,6 +152,17 @@ Internals
 Large Scale
 ===========
 
+Full Threading Support
+----------------------
+
+  Various people have proposed patches to improve threading support
+  in Boost.Python: see the thread at
+  http://aspn.activestate.com/ASPN/Mail/Message/1826544 and
+  http://aspn.activestate.com/ASPN/Mail/Message/1865842 for some
+  examples.  The only problem is that these are incomplete
+  solutions and verifying that we *do* have a complete solution is
+  going to take some time and attention.
+
 Langbinding
 -----------
 
