removed Boost.MPL usage in favor of Boost.Mp11 (#87)

* omitted test_mpl_ops for now

* made IndexSpecifierList a Mp11 sequence

* made nested *_type_list's and tag Mp11 sequences

* leftover MPL->Mp11 change

* removed Clang 5.0 -std=c++1z as not supported by Mp11

* replaced boost::mpl::na with void as default index specifier arg

* removed Clang 5.0 -std=c++1z as not supported by Mp11 (Drone)

* replaced elementary MPL TMP with Mp11/std

* replaced elementary MPL TMP with Mp11/std (tests)

* leftover MPL #include

* suppressed potential narrowing conversion warnings

* enabled macro to support old interface, plus restored and augmented test_mpl_ops

* removed secondary dependency to MPL thru Iterator

* optimized Jamfile.v2

* added conditional support for old definition of tag

* updated MPL support macro in tests

* updated docs

* stylistic

* updated "cxxstd" in libraries.json

* disabled test_serialization for Clang 3.5-3.6 due to lack of support from Boost.SmartPtr

* fixed previous

* removed no longer necessary workaround

* removed redundant dependencies

* updated test description

Author: joaquintides

.drone.jsonnet

@@ -319,7 +319,7 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     linux_pipeline(
         "Linux 18.04 Clang 5.0",
         "cppalliance/droneubuntu1804:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-5.0', CXXSTD: '11,14,1z' },
+        { TOOLSET: 'clang', COMPILER: 'clang++-5.0', CXXSTD: '11,14' },
         "clang-5.0",
     ),
 

.github/workflows/ci.yml

@@ -93,7 +93,7 @@ jobs:
             install: clang-4.0
           - toolset: clang
             compiler: clang++-5.0
-            cxxstd: "11,14,1z"
+            cxxstd: "11,14"
             os: ubuntu-latest
             container: ubuntu:18.04
             install: clang-5.0

CMakeLists.txt

@@ -20,9 +20,8 @@ target_link_libraries(boost_multi_index
     Boost::container_hash
     Boost::core
     Boost::integer
-    Boost::iterator
     Boost::move
-    Boost::mpl
+    Boost::mp11
     Boost::preprocessor
     Boost::smart_ptr
     Boost::static_assert

build.jam

@@ -12,9 +12,8 @@ constant boost_dependencies :
     /boost/container_hash//boost_container_hash
     /boost/core//boost_core
     /boost/integer//boost_integer
-    /boost/iterator//boost_iterator
     /boost/move//boost_move
-    /boost/mpl//boost_mpl
+    /boost/mp11//boost_mp11
     /boost/preprocessor//boost_preprocessor
     /boost/smart_ptr//boost_smart_ptr
     /boost/static_assert//boost_static_assert

doc/compiler_specifics.html

@@ -212,7 +212,7 @@ <h2>
 
 <span class=keyword>namespace</span> <span class=identifier>multi_index</span><span class=special>{</span>
 
-<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T0</span><span class=special>,...,</span><span class=keyword>typename</span> <span class=identifier>Tn</span><span class=special>&gt;</span>
+<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T</span><span class=special>,</span><span class=keyword>typename</span><span class=special>...</span> <span class=identifier>Ts</span><span class=special>&gt;</span>
 <span class=keyword>struct</span> <span class=identifier>indexed_by</span><span class=special>;</span>
 
 <span class=special>}</span> <span class=comment>// namespace boost::multi_index</span> 
@@ -223,24 +223,19 @@ <h2>
 <h3><a name="indexed_by">Class template <code>indexed_by</code></a></h3>
 
 <p>
-<code>indexed_by</code> is a model of
-<a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-<code>MPL Random Access Sequence</code></a> and
-<a href="../../../../libs/mpl/doc/refmanual/extensible-sequence.html">
-<code>MPL Extensible Sequence</code></a> meant to be used to specify a
+<code>indexed_by</code> is meant to be used to specify a
 compile-time list of indices as the <code>IndexSpecifierList</code> of
 <code>multi_index_container</code>.
 </p>
 
 <blockquote><pre>
-<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T0</span><span class=special>,...,</span><span class=keyword>typename</span> <span class=identifier>Tn</span><span class=special>&gt;</span>
+<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T</span><span class=special>,</span><span class=keyword>typename</span><span class=special>...</span> <span class=identifier>Ts</span><span class=special>&gt;</span>
 <span class=keyword>struct</span> <span class=identifier>indexed_by</span><span class=special>;</span>
 </pre></blockquote>
 
 <p>
 Each user-provided element of <code>indexed_list</code> must be an index
-specifier. At least an element must be provided. The maximum number of elements
-of an <code>indexed_by</code> sequence is implementation defined.
+specifier. At least an element must be provided.
 </p>
 
 <h2><a name="tags">Tags</a></h2>
@@ -264,7 +259,7 @@ <h2>
 
 <span class=keyword>namespace</span> <span class=identifier>multi_index</span><span class=special>{</span>
 
-<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T0</span><span class=special>,...,</span><span class=keyword>typename</span> <span class=identifier>Tn</span><span class=special>&gt;</span>
+<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span><span class=special>...</span> <span class=identifier>Ts</span><span class=special>&gt;</span>
 <span class=keyword>struct</span> <span class=identifier>tag</span><span class=special>;</span>
 
 <span class=special>}</span> <span class=comment>// namespace boost::multi_index</span> 
@@ -280,25 +275,13 @@ <h3><a name="tag">Class template <code>tag</code></a></h3>
 </p>
 
 <blockquote><pre>
-<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T0</span><span class=special>,...,</span><span class=keyword>typename</span> <span class=identifier>Tn</span><span class=special>&gt;</span>
-<span class=keyword>struct</span> <span class=identifier>tag</span>
-<span class=special>{</span>
-  <span class=keyword>typedef</span> <b>implementation defined</b> <span class=identifier>type</span><span class=special>;</span>
-<span class=special>};</span>
+<span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>typename</span><span class=special>...</span> <span class=identifier>Ts</span><span class=special>&gt;</span>
+<span class=keyword>struct</span> <span class=identifier>tag</span><span class=special>;</span>
 </pre></blockquote>
 
 <p>
 Elements of <code>tag</code> can be any type, though the user is expected
 to provide classes with mnemonic names. Duplicate elements are not allowed.
-The maximum number of elements of a <code>tag</code> instantiation is
-implementation defined.
-The nested
-<code>type</code> is a model of
-<a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-<code>MPL Random Access Sequence</code></a> and
-<a href="../../../../libs/mpl/doc/refmanual/extensible-sequence.html">
-<code>MPL Extensible Sequence</code></a> containing the types <code>T0</code>, ... ,
-<code>Tn</code> in the same order as specified.
 </p>
 
 <h2><a name="index_catalog">Indices provided by Boost.MultiIndex</a></h2>
@@ -386,9 +369,9 @@ <h2><a name="views">Index views</a></h2>
 
 <br>
 
-<p>Revised January 9th 2020</p>
+<p>Revised October 25th 2025</p>
 
-<p>&copy; Copyright 2003-2020 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
+<p>&copy; Copyright 2003-2025 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
 Distributed under the Boost Software 
 License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
 LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">

doc/reference/indices.html

@@ -235,9 +235,8 @@ <h3><a name="multi_index_container">
 <p>
 A <code>multi_index_container</code> type is instantiated with the type of the
 elements contained and a non-empty
-<a href="../../../../libs/mpl/doc/refmanual/forward-sequence.html">
-<code>MPL Forward Sequence</code></a> specifying which indices conform the
-class.
+<a href="../../../../libs/mp11/doc/html/mp11.html#definitions">Mp11 list</a>
+specifying which indices conform the class.
 </p>
 
 <p>
@@ -531,13 +530,10 @@ <h4><a name="instantiation_types">Instantiation types</a></h4>
   </li>
   <li><code>IndexSpecifierList</code> specifies the indices that the
     <code>multi_index_container</code> is composed of. It must be a non-empty
-    <a href="../../../../libs/mpl/doc/refmanual/forward-sequence.html">
-    <code>MPL Forward Sequence</code></a> (and, preferably,
-    an <a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-    <code>MPL Random Access Sequence</code></a>) of index specifiers. For
-    syntactic convenience, the
+    <a href="../../../../libs/mp11/doc/html/mp11.html#definitions">Mp11 list</a>
+    of index specifiers. For syntactic convenience, the
     <a href="indices.html#indexed_by"><code>indexed_by</code></a>
-    MPL sequence can be used.
+    construct can be used.
   </li>
   <li><code>Allocator</code> must be an allocator of <code>Value</code> objects
     satisfying the associated C++ requirements at <b>[allocator.requirements]</b>.
@@ -598,34 +594,25 @@ <h4><a name="types">Nested types</a></h4>
 <code>index_type_list</code>
 
 <blockquote>
-Model of
-<a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-<code>MPL Random Access Sequence</code></a> and
-<a href="../../../../libs/mpl/doc/refmanual/extensible-sequence.html">
-<code>MPL Extensible Sequence</code></a> containing the types of the indices held by
+<a href="../../../../libs/mp11/doc/html/mp11.html#definitions">Mp11 list</a>
+containing the types of the indices held by
 the <code>multi_index_container</code>, in the same order as they were specified.
 </blockquote>
 
 <code>iterator_type_list</code>
 
 <blockquote>
-Model of
-<a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-<code>MPL Random Access Sequence</code></a> and
-<a href="../../../../libs/mpl/doc/refmanual/extensible-sequence.html">
-<code>MPL Extensible Sequence</code></a> containing the types of the iterators of
+<a href="../../../../libs/mp11/doc/html/mp11.html#definitions">Mp11 list</a>
+containing the types of the iterators of
 the indices held by the <code>multi_index_container</code>, in the same order as they were
 specified.
 </blockquote>
 
 <code>const_iterator_type_list</code>
 
 <blockquote>
-Model of
-<a href="../../../../libs/mpl/doc/refmanual/random-access-sequence.html">
-<code>MPL Random Access Sequence</code></a> and
-<a href="../../../../libs/mpl/doc/refmanual/extensible-sequence.html">
-<code>MPL Extensible Sequence</code></a> containing the types of the constant
+<a href="../../../../libs/mp11/doc/html/mp11.html#definitions">Mp11 list</a>
+containing the types of the constant
 iterators of the indices held by the <code>multi_index_container</code>, in the same order
 as they were specified.
 </blockquote>
@@ -1082,9 +1069,9 @@ <h4><a name="serialization">Serialization</a></h4>
 
 <br>
 
-<p>Revised August 15th 2022</p>
+<p>Revised October 25th 2025</p>
 
-<p>&copy; Copyright 2003-2022 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
+<p>&copy; Copyright 2003-2025 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
 Distributed under the Boost Software 
 License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
 LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">

doc/reference/multi_index_container.html

@@ -30,6 +30,7 @@ <h1><img src="../../../boost.png" alt="boost.png (6897 bytes)" align=
 <h2>Contents</h2>
 
 <ul>
+  <li><a href="#boost_1_91">Boost 1.91 release</a></li>
   <li><a href="#boost_1_85">Boost 1.85 release</a></li>
   <li><a href="#boost_1_84">Boost 1.84 release</a></li>
   <li><a href="#boost_1_83">Boost 1.83 release</a></li>
@@ -72,6 +73,26 @@ <h2>Contents</h2>
   <li><a href="#boost_1_33">Boost 1.33 release</a></li>
 </ul>
 
+<h2><a name="boost_1_91">Boost 1.91 release</a></h2>
+
+<p>
+<ul>
+  <li><b>Breaking change:</b> All type lists accepted or provided by the library (<code>indexed_by</code>,
+    <code>tag</code>, nested typedefs <code>index_specifier_type_list</code>,
+    <code>index_type_list</code>, <code>iterator_type_list</code> and
+    <code>const_iterator_type_list</code>) are no longer based on
+    <a href="../../mpl">Boost.MPL</a> but instead they are now
+    <a href="../../mp11/doc/html/mp11.html#definitions">Boost.Mp11 lists</a>.
+    As a result, Boost.MultiIndex doesn't depend anymore on Boost.MPL.
+    It is expected that most user code won't be impacted by this
+    change, but the previous behavior may be restored, however, by
+    globally defining the macro
+    <code>BOOST_MULTI_INDEX_ENABLE_MPL_SUPPORT</code>.
+    Legacy support for Boost.MPL may be eventually deprecated and removed in the future.
+  </li>
+</ul>
+</p>
+
 <h2><a name="boost_1_85">Boost 1.85 release</a></h2>
 
 <p>
@@ -815,9 +836,9 @@ <h2><a name="boost_1_33">Boost 1.33 release</a></h2>
 
 <br>
 
-<p>Revised March 15th 2024</p>
+<p>Revised October 25th 2025</p>
 
-<p>&copy; Copyright 2003-2024 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
+<p>&copy; Copyright 2003-2025 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
 Distributed under the Boost Software 
 License, Version 1.0. (See accompanying file <a href="../../../LICENSE_1_0.txt">
 LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">

doc/release_notes.html

@@ -101,7 +101,7 @@ <h1><img src="../../../boost.png" alt="boost.png (6897 bytes)" align=
 </tr>
 <tr class="odd_tr">
   <td><a href="../test/test_mpl_ops.cpp"><code>test_mpl_ops.cpp</code></a></td>
-  <td>Metaprogramming manipulations of <code>multi_index_container</code> types.</td>
+  <td>Boost.MPL interoperability (when <code> BOOST_MULTI_INDEX_ENABLE_MPL_SUPPORT</code> is enabled).</td>
 </tr>
 <tr>
   <td><a href="../test/test_node_handling.cpp"><code>test_node_handling.cpp</code></a></td>
@@ -166,9 +166,9 @@ <h1><img src="../../../boost.png" alt="boost.png (6897 bytes)" align=
 
 <br>
 
-<p>Revised May 9th 2020</p>
+<p>Revised October 26th 2025</p>
 
-<p>&copy; Copyright 2003-2020 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
+<p>&copy; Copyright 2003-2025 Joaqu&iacute;n M L&oacute;pez Mu&ntilde;oz.
 Distributed under the Boost Software 
 License, Version 1.0. (See accompanying file <a href="../../../LICENSE_1_0.txt">
 LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">