From 247ffd0336bb7f6ca9c6ee8a4adad8174b3b67c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ion=20Gazta=C3=B1aga?= <igaztanaga@gmail.com>
Date: Mon, 27 Oct 2025 23:55:05 +0100
Subject: [PATCH] Fixes #304 ("Usage of boost::container::small_vector with
 custom allocator")

---
 doc/container.qbk                        | 3 ++-
 include/boost/container/small_vector.hpp | 7 +++++--
 test/vector_test.hpp                     | 7 +++++--
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/doc/container.qbk b/doc/container.qbk
index a530492..3b94449 100644
--- a/doc/container.qbk
+++ b/doc/container.qbk
@@ -1434,7 +1434,7 @@ use [*Boost.Container]? There are several reasons for that:
 
 [section:release_notes Release Notes]
 
-[section:release_notes_boost_1_90_00 Boost    Release]
+[section:release_notes_boost_1_90_00 Boost 1.90 Release]
 
 * Reimplemented [classref boost::container::deque]. The original implementation was based on
    the SGI's original data structure (similar to libstdc++). Main changes:
@@ -1450,6 +1450,7 @@ use [*Boost.Container]? There are several reasons for that:
    * [@https://github.com/boostorg/container/pull/317/ GitHub #293: ['"UBSAN reports unaligned access error"]].
    * [@https://github.com/boostorg/container/pull/294 GitHub #294: ['"CMake: Add option to use header-only Boost::container"]].
    * [@https://github.com/boostorg/container/issues/300 GitHub #300: ['"Warnings when building with clang-20"]].
+   * [@https://github.com/boostorg/container/issues/300 GitHub #304: ['"Usage of boost::container::small_vector with custom allocator"]].
    * [@https://github.com/boostorg/container/pull/305 GitHub #305: ['"Warnings with -Wstrict-prototypes"]].
    * [@https://github.com/boostorg/container/pull/307 GitHub #307: ['"Fix all instances of MSVC warning C4146 (unsigned negation)"]].
    * [@https://github.com/boostorg/container/issues/309 GitHub #309: ['"Performance regression of boost::container::static_vector introduced in boost v1.86"]].
diff --git a/include/boost/container/small_vector.hpp b/include/boost/container/small_vector.hpp
index afed910..c01718a 100644
--- a/include/boost/container/small_vector.hpp
+++ b/include/boost/container/small_vector.hpp
@@ -127,10 +127,11 @@ class small_vector_allocator
 {
    typedef unsigned int allocation_type;
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
-   private:
 
+   public:
    typedef typename allocator_traits<VoidAlloc>::template portable_rebind_alloc<T>::type allocator_type;
 
+   private:
    BOOST_COPYABLE_AND_MOVABLE(small_vector_allocator)
 
    inline const allocator_type &as_base() const BOOST_NOEXCEPT
@@ -353,7 +354,8 @@ class small_vector_base
    typedef typename real_allocator<T, SecAlloc>::type                     underlying_allocator_t;
    typedef typename allocator_traits<underlying_allocator_t>::
       template portable_rebind_alloc<void>::type                          void_underlying_allocator_t;
-   typedef small_vector_allocator<T, void_underlying_allocator_t, Options>allocator_type;
+   typedef typename small_vector_allocator
+      <T, void_underlying_allocator_t, Options>::allocator_type           allocator_type;
    typedef typename dtl::get_small_vector_opt<Options>::type              options_t;
    typedef typename dtl::vector_for_small_vector
       <T, SecAlloc, Options>::type                                        base_type;
@@ -548,6 +550,7 @@ class small_vector
    BOOST_COPYABLE_AND_MOVABLE(small_vector)
 
    public:
+   typedef dtl::true_type is_partially_propagable;
    typedef small_vector_base<T, Allocator, Options>   base_type;
    typedef typename base_type::allocator_type         allocator_type;
    typedef typename base_type::size_type              size_type;
diff --git a/test/vector_test.hpp b/test/vector_test.hpp
index b120d5a..fb2550f 100644
--- a/test/vector_test.hpp
+++ b/test/vector_test.hpp
@@ -626,8 +626,11 @@ int vector_test()
       if(!test::CheckEqualContainers(*boostvectorp2, *stdvectorp)) return 1;
    }
 
-   if (0 != vector_test_fully_propagable<MyBoostVector>
-         ( dtl::bool_< !allocator_traits<typename MyBoostVector::allocator_type>::is_partially_propagable::value >() ))   return 1;
+   typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_DEFAULT(boost::container::dtl::, MyBoostVector,
+      is_partially_propagable, dtl::false_type)
+         is_partially_propagable_t;
+
+   if (0 != vector_test_fully_propagable<MyBoostVector>( dtl::bool_< !is_partially_propagable_t::value >() ))   return 1;
 
    if (0 != vector_move_assignable_only< MyBoostVector>(dtl::bool_<boost::container::test::is_move_assignable<IntType>::value>()))
       return 1;