Fix GCC 4.8 Drone job to actually use 4.8

OpenHarmony doesn't support pthread_setcancelstate.

.drone.jsonnet

@@ -32,6 +32,8 @@ local linux_pipeline(name, image, environment, packages = "", sources = [], arch
             commands:
             [
                 'set -e',
+                'uname -a',
+                'echo $DRONE_STAGE_MACHINE',
                 'wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -',
             ] +
             (if sources != [] then [ ('apt-add-repository "' + source + '"') for source in sources ] else []) +
@@ -122,7 +124,7 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     linux_pipeline(
         "Linux 16.04 GCC 4.8 32/64",
         "cppalliance/droneubuntu1604:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11', ADDRMD: '32,64' },
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.8', CXXSTD: '03,11', ADDRMD: '32,64' },
         "g++-4.8-multilib",
     ),
 
@@ -200,31 +202,37 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 32 ASAN",
-        "cppalliance/droneubuntu2304:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + asan,
-        "g++-13-multilib",
+        "Linux 24.04 GCC 13* 32/64",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32,64' },
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 64 ASAN",
-        "cppalliance/droneubuntu2304:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + asan,
-        "g++-13-multilib",
+        "Linux 24.04 GCC 14 32 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + asan,
+        "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 32 UBSAN",
-        "cppalliance/droneubuntu2304:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + ubsan,
-        "g++-13-multilib",
+        "Linux 24.04 GCC 14 64 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + asan,
+        "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 64 UBSAN",
-        "cppalliance/droneubuntu2304:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + ubsan,
-        "g++-13-multilib",
+        "Linux 24.04 GCC 14 32 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + ubsan,
+        "g++-14-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 GCC 14 64 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + ubsan,
+        "g++-14-multilib",
     ),
 
     linux_pipeline(
@@ -347,24 +355,38 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 23.04 Clang 16",
-        "cppalliance/droneubuntu2304:1",
+        "Linux 24.04 Clang 16",
+        "cppalliance/droneubuntu2404:1",
         { TOOLSET: 'clang', COMPILER: 'clang++-16', CXXSTD: '03,11,14,17,20,2b' },
         "clang-16",
     ),
 
     linux_pipeline(
-        "Linux 23.10 Clang 17 UBSAN",
-        "cppalliance/droneubuntu2310:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '03,11,14,17,20,2b' } + ubsan,
+        "Linux 24.04 Clang 17",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '03,11,14,17,20,2b' },
         "clang-17",
     ),
 
     linux_pipeline(
-        "Linux 23.10 Clang 17 ASAN",
-        "cppalliance/droneubuntu2310:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '03,11,14,17,20,2b' } + asan,
-        "clang-17",
+        "Linux 24.04 Clang 18 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '03,11,14,17,20,2b' } + ubsan,
+        "clang-18",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 Clang 18 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '03,11,14,17,20,2b' } + asan,
+        "clang-18",
+    ),
+
+    linux_pipeline(
+        "Linux 24.10 Clang 19",
+        "cppalliance/droneubuntu2410:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-19', CXXSTD: '03,11,14,17,20,2b' },
+        "clang-19",
     ),
 
     macos_pipeline(

.github/workflows/ci.yml

@@ -125,9 +125,16 @@ jobs:
             cxxstd: "03,11,14,17,20,23"
             address-model: 32,64
             os: ubuntu-latest
-            container: ubuntu:23.04
+            container: ubuntu:24.04
             install:
               - g++-13-multilib
+          - toolset: gcc-14
+            cxxstd: "03,11,14,17,20,23"
+            address-model: 32,64
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install:
+              - g++-14-multilib
           - name: UBSAN
             toolset: gcc-12
             cxxstd: "03,11,14,17,20,23"
@@ -276,7 +283,7 @@ jobs:
             compiler: clang++-16
             cxxstd: "03,11,14,17,20,2b"
             os: ubuntu-latest
-            container: ubuntu:23.04
+            container: ubuntu:24.04
             install:
               - clang-16
               - libc++-16-dev
@@ -286,15 +293,34 @@ jobs:
           - toolset: clang
             compiler: clang++-17
             cxxstd: "03,11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:24.04
             install:
               - clang-17
               - libc++-17-dev
               - libc++abi-17-dev
-            sources:
-              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main"
-            source_keys:
-              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+            cxxflags: -stdlib=libc++
+            linkflags: -stdlib=libc++
+          - toolset: clang
+            compiler: clang++-18
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install:
+              - clang-18
+              - libc++-18-dev
+              - libc++abi-18-dev
+            cxxflags: -stdlib=libc++
+            linkflags: -stdlib=libc++
+          - toolset: clang
+            compiler: clang++-19
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:24.10
+            install:
+              - clang-19
+              - libc++-19-dev
+              - libc++abi-19-dev
             cxxflags: -stdlib=libc++
             linkflags: -stdlib=libc++
           - name: UBSAN
@@ -310,15 +336,15 @@ jobs:
               - libc++-15-dev
               - libc++abi-15-dev
 
-          - toolset: clang
-            cxxstd: "03,11,14,17,2a"
-            os: macos-11
-          - toolset: clang
-            cxxstd: "03,11,14,17,20,2b"
-            os: macos-12
           - toolset: clang
             cxxstd: "03,11,14,17,20,2b"
             os: macos-13
+          - toolset: clang
+            cxxstd: "03,11,14,17,20,2b"
+            os: macos-14
+          - toolset: clang
+            cxxstd: "03,11,14,17,20,2b"
+            os: macos-15
 
     timeout-minutes: 45
     runs-on: ${{matrix.os}}
@@ -611,9 +637,10 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
           - os: macos-13
+          - os: macos-14
+          - os: macos-15
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 10
@@ -678,9 +705,10 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
           - os: macos-13
+          - os: macos-14
+          - os: macos-15
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 10
@@ -755,9 +783,10 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
           - os: macos-13
+          - os: macos-14
+          - os: macos-15
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 20

build.jam

@@ -0,0 +1,23 @@
+# Copyright 2023-2024 René Ferdinand Rivera Morell
+# Copyright 2024 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+require-b2 5.2 ;
+
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/static_assert//boost_static_assert
+    /boost/throw_exception//boost_throw_exception
+    ;
+
+project /boost/core ;
+
+explicit
+    [ alias boost_core : : : : <include>include <library>$(boost_dependencies) ]
+    [ alias all : boost_core test ]
+    ;
+
+call-if : boost-library core
+    ;

doc/Jamfile.v2

@@ -9,7 +9,7 @@ import project ;
 import doxygen ;
 import quickbook ;
 
-path-constant INCLUDES : ../../.. ;
+path-constant INCLUDES : ../include ;
 
 doxygen ref_reference
   :

doc/changes.qbk

@@ -7,12 +7,24 @@
 
 [section Revision History]
 
+[section Changes in 1.86.0]
+
+* Added a [link core.pointer_in_range `boost/core/pointer_in_range.hpp`] header with a `pointer_in_range`
+  function template to check if a pointer is within a given range.
+* Fixed `type_name` for abstract classes. ([github_issue 172])
+* Fixed `boost/core/type_name.hpp` compilation error with MSVC with disabled native `wchar_t` type.
+  ([github_issue 173])
+* Added a workaround for an MSVC [@https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025 bug]
+  causing `empty_value` compilation errors when it is used with a nested class. ([github_pr 175])
+
+[endsect]
+
 [section Changes in 1.85.0]
 
 * Added a new [link core.functor `boost/core/functor.hpp`] header with a `functor` class template
   for wrapping a raw function into a function object class.
 * Changed [link core.null_deleter `null_deleter`], [link core.fclose_deleter `fclose_deleter`]
-  and [link.checked_delete checked deleter] definitions so that they don't bring namespace `boost`
+  and [link core.checked_delete checked deleter] definitions so that they don't bring namespace `boost`
   into argument-dependent lookup in cases like this:
   ```
   std::unique_ptr< std::FILE, boost::fclose_deleter > p1, p2;

doc/core.qbk

@@ -20,6 +20,9 @@ or copy at http://boost.org/LICENSE_1_0.txt)
   ]
 ]
 
+[template github_issue[key]'''<ulink url="https://github.com/boostorg/core/issues/'''[key]'''">#'''[key]'''</ulink>''']
+[template github_pr[key]'''<ulink url="https://github.com/boostorg/core/pull/'''[key]'''">PR#'''[key]'''</ulink>''']
+
 [template simplesect[title]
 [block '''<simplesect><title>'''[title]'''</title>''']]
 

doc/pointer_in_range.qbk

@@ -33,7 +33,7 @@ template<class T, class N>
 void
 Allocator<T, N>::deallocate(pointer ptr, size_type)
 {
-    if (!boost::pointer_in_range(ptr, &buffer_[0], &buffer_[N])) {
+    if (!boost::pointer_in_range(ptr, buffer_, buffer_ + N)) {
         ::operator delete(ptr);
     }
 }
@@ -56,8 +56,9 @@ constexpr bool pointer_in_range(const T* ptr, const T* begin, const T* end);
 
 [variablelist
 [[`template<class T> constexpr bool pointer_in_range(const T* ptr,
-const T* begin, T* end);`]
+const T* begin, const T* end);`]
 [[variablelist
+[[Requires][`[begin,end)` is a valid range.]]
 [[Returns][`true` if `ptr` is in range `[begin,end)`, otherwise `false`.]]]]]]
 
 [endsect]

include/boost/core/detail/assert.hpp

@@ -0,0 +1,18 @@
+/*
+Copyright 2025 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#undef BOOST_CORE_DETAIL_ASSERT
+
+#if !defined(__clang__) && \
+    !defined(__INTEL_COMPILER) && \
+    defined(__GNUC__) && \
+    (__GNUC__ < 5)
+#define BOOST_CORE_DETAIL_ASSERT(expr) void(0)
+#else
+#include <boost/assert.hpp>
+#define BOOST_CORE_DETAIL_ASSERT(expr) BOOST_ASSERT(expr)
+#endif

include/boost/core/detail/minstd_rand.hpp

@@ -0,0 +1,58 @@
+#ifndef BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED
+
+// Copyright 2017 Peter Dimov
+//
+// Distributed under 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
+//
+// An implementation of minstd_rand that does not require
+// the Random library
+
+#include <boost/cstdint.hpp>
+
+namespace boost
+{
+namespace detail
+{
+
+class minstd_rand
+{
+private:
+
+    boost::uint_least32_t x_;
+
+    enum { a = 48271, m = 2147483647 };
+
+public:
+
+    minstd_rand(): x_( 1 )
+    {
+    }
+
+    explicit minstd_rand( boost::uint_least32_t x ): x_( x % m )
+    {
+        if( x_ == 0 )
+        {
+            x_ = 1;
+        }
+    }
+
+    boost::uint_least32_t operator()()
+    {
+        boost::uint_least64_t y = x_;
+
+        y = ( a * y ) % m;
+
+        x_ = static_cast<boost::uint_least32_t>( y );
+
+        return x_;
+    }
+};
+
+} // namespace detail
+} // namespace boost
+
+#endif // #ifndef BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED

include/boost/core/detail/sp_thread_sleep.hpp

@@ -67,7 +67,7 @@ namespace core
 
 inline void sp_thread_sleep() BOOST_NOEXCEPT
 {
-#if defined(BOOST_HAS_PTHREADS) && !defined(__ANDROID__)
+#if defined(BOOST_HAS_PTHREADS) && !defined(__ANDROID__) && !defined(__OHOS__)
 
     int oldst;
     pthread_setcancelstate( PTHREAD_CANCEL_DISABLE, &oldst );
@@ -85,7 +85,7 @@ inline void sp_thread_sleep() BOOST_NOEXCEPT
 
     nanosleep( &rqtp, 0 );
 
-#if defined(BOOST_HAS_PTHREADS) && !defined(__ANDROID__)
+#if defined(BOOST_HAS_PTHREADS) && !defined(__ANDROID__) && !defined(__OHOS__)
 
     pthread_setcancelstate( oldst, &oldst );
 

include/boost/core/detail/string_view.hpp

@@ -41,9 +41,6 @@ namespace boost
 // forward declaration of boost::basic_string_view from Utility
 template<class Ch, class Tr> class basic_string_view;
 
-// forward declaration of boost::hash_range from ContainerHash
-template<class It> std::size_t hash_range( It, It );
-
 namespace core
 {
 namespace detail
@@ -74,7 +71,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_of( Ch const* p_
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -91,7 +88,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_of( Ch const* p_
     {
         for( std::size_t i = pos; i < n_; ++i )
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
             if( ch >= 0 && ch < 256 && table[ ch ] ) return i;
         }
     }
@@ -129,7 +126,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_of( Ch const* p_,
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -150,7 +147,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_of( Ch const* p_,
     {
         do
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
 
             if( ch >= 0 && ch < 256 && table[ ch ] ) return i;
 
@@ -199,7 +196,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_not_of( Ch const
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -216,7 +213,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_not_of( Ch const
     {
         for( std::size_t i = pos; i < n_; ++i )
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
             if( !( ch >= 0 && ch < 256 && table[ ch ] ) ) return i;
         }
     }
@@ -262,7 +259,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_not_of( Ch const*
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -283,7 +280,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_not_of( Ch const*
     {
         do
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
 
             if( !( ch >= 0 && ch < 256 && table[ ch ] ) ) return i;
 
@@ -381,7 +378,7 @@ public:
     }
 
     template<class End> BOOST_CXX14_CONSTEXPR basic_string_view( Ch const* first, End last,
-        typename boost::enable_if<boost::core::detail::is_same<End, Ch const*> >::type* = 0 ) BOOST_NOEXCEPT: p_( first ), n_( last - first )
+        typename boost::enable_if<boost::core::detail::is_same<End, Ch const*>, int >::type = 0 ) BOOST_NOEXCEPT: p_( first ), n_( static_cast<size_type>( last - first ) )
     {
         BOOST_ASSERT( last - first >= 0 );
     }
@@ -399,7 +396,7 @@ public:
 #endif
 
     template<class Ch2> basic_string_view( boost::basic_string_view<Ch2, std::char_traits<Ch2> > const& str,
-        typename boost::enable_if<boost::core::detail::is_same<Ch, Ch2> >::type* = 0 ) BOOST_NOEXCEPT: p_( str.data() ), n_( str.size() )
+        typename boost::enable_if<boost::core::detail::is_same<Ch, Ch2>, int >::type = 0 ) BOOST_NOEXCEPT: p_( str.data() ), n_( str.size() )
     {
     }
 
@@ -681,7 +678,7 @@ public:
 
         Ch const* r = traits_type::find( data() + pos, size() - pos, c );
 
-        return r? r - data(): npos;
+        return r? static_cast<size_type>( r - data() ): npos;
     }
 
     BOOST_CXX14_CONSTEXPR size_type find( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
@@ -696,11 +693,11 @@ public:
 
         for( ;; )
         {
-            p = traits_type::find( p, last - p, s[0] );
+            p = traits_type::find( p, static_cast<size_type>( last - p ), s[0] );
 
             if( p == 0 ) break;
 
-            if( traits_type::compare( p + 1, s + 1, n - 1 ) == 0 ) return p - data();
+            if( traits_type::compare( p + 1, s + 1, n - 1 ) == 0 ) return static_cast<size_type>( p - data() );
 
             ++p;
         }
@@ -1181,11 +1178,6 @@ public:
     }
 
 #endif
-
-    inline friend std::size_t hash_value( basic_string_view const& sv )
-    {
-        return boost::hash_range( sv.begin(), sv.end() );
-    }
 };
 
 // stream inserter
@@ -1193,7 +1185,7 @@ public:
 template<class Ch> std::basic_ostream<Ch>& operator<<( std::basic_ostream<Ch>& os, basic_string_view<Ch> str )
 {
     Ch const* p = str.data();
-    std::streamsize n = str.size();
+    std::streamsize n = static_cast<std::streamsize>( str.size() );
 
     std::streamsize m = os.width();
 

include/boost/core/empty_value.hpp

@@ -95,9 +95,57 @@ private:
 };
 
 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
+#if defined(BOOST_MSVC)
+/*
+This is a workaround to an MSVC bug when T is a nested class:
+https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025
+*/
+namespace detail {
+
+template<class T>
+class empty_value_base
+    : public T {
+public:
+#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)
+    empty_value_base() = default;
+#else
+    BOOST_CONSTEXPR empty_value_base() { }
+#endif
+
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+    template<class U, class... Args>
+    BOOST_CONSTEXPR empty_value_base(U&& value, Args&&... args)
+        : T(std::forward<U>(value), std::forward<Args>(args)...) { }
+#else
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(U&& value)
+        : T(std::forward<U>(value)) { }
+#endif
+#else
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(const U& value)
+        : T(value) { }
+
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(U& value)
+        : T(value) { }
+#endif
+};
+
+} /* detail */
+#endif
+
 template<class T, unsigned N>
 class empty_value<T, N, true>
+#if defined(BOOST_MSVC)
+    : detail::empty_value_base<T> {
+    typedef detail::empty_value_base<T> empty_base_;
+#else
     : T {
+    typedef T empty_base_;
+#endif
+
 public:
     typedef T type;
 
@@ -108,26 +156,26 @@ public:
 #endif
 
     BOOST_CONSTEXPR empty_value(boost::empty_init_t)
-        : T() { }
+        : empty_base_() { }
 
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
     template<class U, class... Args>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U&& value, Args&&... args)
-        : T(std::forward<U>(value), std::forward<Args>(args)...) { }
+        : empty_base_(std::forward<U>(value), std::forward<Args>(args)...) { }
 #else
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U&& value)
-        : T(std::forward<U>(value)) { }
+        : empty_base_(std::forward<U>(value)) { }
 #endif
 #else
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, const U& value)
-        : T(value) { }
+        : empty_base_(value) { }
 
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U& value)
-        : T(value) { }
+        : empty_base_(value) { }
 #endif
 
     BOOST_CONSTEXPR const T& get() const BOOST_NOEXCEPT {

include/boost/core/lightweight_test.hpp

@@ -153,6 +153,7 @@ inline void no_throw_failed_impl(const char* expr, const char* what, const char*
 #elif defined(__GNUC__) && !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 406
 # pragma GCC diagnostic push
 # pragma GCC diagnostic ignored "-Wsign-compare"
+# pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
 
 // specialize test output for char pointers to avoid printing as cstring

include/boost/core/span.hpp

@@ -8,6 +8,7 @@ Distributed under the Boost Software License, Version 1.0.
 #ifndef BOOST_CORE_SPAN_HPP
 #define BOOST_CORE_SPAN_HPP
 
+#include <boost/core/detail/assert.hpp>
 #include <boost/core/data.hpp>
 #include <array>
 #include <iterator>
@@ -274,17 +275,21 @@ public:
     }
 
     constexpr span<T, dynamic_extent> first(size_type c) const {
-        return span<T, dynamic_extent>(s_.p, c);
+        return BOOST_CORE_DETAIL_ASSERT(c <= size()),
+            span<T, dynamic_extent>(s_.p, c);
     }
 
     constexpr span<T, dynamic_extent> last(size_type c) const {
-        return span<T, dynamic_extent>(s_.p + (s_.n - c), c);
+        return BOOST_CORE_DETAIL_ASSERT(c <= size()),
+            span<T, dynamic_extent>(s_.p + (s_.n - c), c);
     }
 
     constexpr span<T, dynamic_extent> subspan(size_type o,
         size_type c = dynamic_extent) const {
-        return span<T, dynamic_extent>(s_.p + o,
-            c == dynamic_extent ? s_.n - o : c);
+        return BOOST_CORE_DETAIL_ASSERT(o <= size() &&
+                (c == dynamic_extent || c + o <= size())),
+            span<T, dynamic_extent>(s_.p + o,
+                c == dynamic_extent ? s_.n - o : c);
     }
 
     constexpr size_type size() const noexcept {
@@ -300,15 +305,15 @@ public:
     }
 
     constexpr reference operator[](size_type i) const {
-        return s_.p[i];
+        return BOOST_CORE_DETAIL_ASSERT(i < size()), s_.p[i];
     }
 
     constexpr reference front() const {
-        return *s_.p;
+        return BOOST_CORE_DETAIL_ASSERT(!empty()), *s_.p;
     }
 
     constexpr reference back() const {
-        return s_.p[s_.n - 1];
+        return BOOST_CORE_DETAIL_ASSERT(!empty()), s_.p[s_.n - 1];
     }
 
     constexpr pointer data() const noexcept {
@@ -351,8 +356,10 @@ private:
     detail::span_store<T, E> s_;
 };
 
+#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
 template<class T, std::size_t E>
 constexpr std::size_t span<T, E>::extent;
+#endif
 
 #ifdef __cpp_deduction_guides
 template<class I, class L>

include/boost/core/type_name.hpp

@@ -103,7 +103,8 @@ inline std::string fix_typeid_name( char const* n )
 }
 
 // class types can be incomplete
-template<class T> std::string typeid_name_impl( int T::* )
+// but also abstract (T[1] doesn't form)
+template<class T> std::string typeid_name_impl( int T::*, T(*)[1] )
 {
     std::string r = fix_typeid_name( typeid(T[1]).name() );
     return r.substr( 0, r.size() - 4 ); // remove ' [1]' suffix
@@ -116,7 +117,7 @@ template<class T> std::string typeid_name_impl( ... )
 
 template<class T> std::string typeid_name()
 {
-    return typeid_name_impl<T>( 0 );
+    return typeid_name_impl<T>( 0, 0 );
 }
 
 // template names
@@ -345,6 +346,8 @@ template<> struct tn_holder<boost::uint128_type>
 
 #endif
 
+#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
+
 template<> struct tn_holder<wchar_t>
 {
     static std::string type_name( std::string const& suffix )
@@ -353,6 +356,8 @@ template<> struct tn_holder<wchar_t>
     }
 };
 
+#endif
+
 #if !defined(BOOST_NO_CXX11_CHAR16_T)
 
 template<> struct tn_holder<char16_t>

test/CMakeLists.txt

@@ -8,17 +8,6 @@ if(HAVE_BOOST_TEST)
 
 boost_test_jamfile(FILE Jamfile.v2 LINK_LIBRARIES Boost::core Boost::static_assert Boost::type_traits)
 
-set(BOOST_TEST_LINK_LIBRARIES Boost::core Boost::type_traits)
-
-boost_test(TYPE run SOURCES eif_constructors.cpp)
-boost_test(TYPE run SOURCES eif_dummy_arg_disambiguation.cpp)
-boost_test(TYPE run SOURCES eif_lazy.cpp)
-boost_test(TYPE run SOURCES eif_lazy_test.cpp)
-boost_test(TYPE run SOURCES eif_member_templates.cpp)
-boost_test(TYPE run SOURCES eif_namespace_disambiguation.cpp)
-boost_test(TYPE run SOURCES eif_no_disambiguation.cpp)
-boost_test(TYPE run SOURCES eif_partial_specializations.cpp)
-
 set(BOOST_TEST_LINK_LIBRARIES Boost::core Boost::throw_exception)
 
 boost_test(TYPE run SOURCES no_exceptions_support_test.cpp)
@@ -27,6 +16,10 @@ set(BOOST_TEST_LINK_LIBRARIES Boost::core Boost::utility)
 
 boost_test(TYPE run SOURCES sv_conversion_test2.cpp)
 
+set(BOOST_TEST_LINK_LIBRARIES Boost::core Boost::container_hash)
+
+boost_test(TYPE run SOURCES sv_hash_test.cpp)
+
 set(BOOST_TEST_LINK_LIBRARIES Boost::core Boost::config Boost::move Boost::smart_ptr)
 
 boost_test(TYPE run SOURCES fclose_deleter_test.cpp)

test/Jamfile.v2

@@ -6,11 +6,15 @@
 #  See accompanying file LICENSE_1_0.txt or copy at
 #  http://www.boost.org/LICENSE_1_0.txt
 
+require-b2 5.0.1 ;
+import-search /boost/config/checks ;
+import config : requires ;
 import modules ;
 import testing ;
 
 project : requirements
-
+  <library>/boost/core//boost_core
+  <library>/boost/type_traits//boost_type_traits
   <warnings>extra
   <toolset>msvc:<warnings-as-errors>on
   <toolset>clang:<warnings-as-errors>on
@@ -22,6 +26,17 @@ local warnings-as-errors-off =
     "-<toolset>gcc:<warnings-as-errors>on"
     "-<toolset>clang:<warnings-as-errors>on" ;
 
+local pedantic-errors = <warnings>pedantic
+    <toolset>gcc:<cxxflags>"-Wconversion"
+    <toolset>gcc:<cxxflags>"-Wsign-conversion"
+    <toolset>clang:<cxxflags>"-Wconversion"
+    <toolset>clang:<cxxflags>"-Wsign-conversion"
+    <toolset>msvc:<warnings-as-errors>on
+    <toolset>gcc:<warnings-as-errors>on
+    <toolset>clang:<warnings-as-errors>on ;
+
+local CPP11 = [ requires cxx11_variadic_templates cxx11_template_aliases cxx11_decltype cxx11_constexpr cxx11_noexcept cxx11_ref_qualifiers ] ;
+
 # quick test (for CI)
 run quick.cpp ;
 
@@ -34,7 +49,8 @@ compile addressof_constexpr_test.cpp ;
 compile-fail addressof_fail_rvalue.cpp
   : $(warnings-as-errors-off) ;
 
-run checked_delete_test.cpp ;
+run checked_delete_test.cpp
+  : : : $(pedantic-errors) ;
 compile-fail checked_delete_fail.cpp
   : $(warnings-as-errors-off) ;
 compile-fail checked_delete_fail2.cpp
@@ -69,14 +85,14 @@ compile-fail ref_implicit_fail4.cpp
 run ref_cv_test.cpp ;
 run ref_conversion_test.cpp ;
 
-run eif_constructors.cpp : ;
-run eif_dummy_arg_disambiguation.cpp : ;
-run eif_lazy.cpp : ;
-run eif_lazy_test.cpp : ;
-run eif_member_templates.cpp : ;
-run eif_namespace_disambiguation.cpp : ;
-run eif_no_disambiguation.cpp : ;
-run eif_partial_specializations.cpp : ;
+run eif_constructors.cpp ;
+run eif_dummy_arg_disambiguation.cpp ;
+run eif_lazy.cpp ;
+run eif_lazy_test.cpp ;
+run eif_member_templates.cpp ;
+run eif_namespace_disambiguation.cpp ;
+run eif_no_disambiguation.cpp ;
+run eif_partial_specializations.cpp ;
 
 compile-fail noncopyable_compile_fail.cpp
   : $(warnings-as-errors-off) ;
@@ -101,13 +117,6 @@ run visit_each_test.cpp ;
 
 run get_pointer_test.cpp ;
 
-local pedantic-errors = <warnings>pedantic
-    <toolset>gcc:<cxxflags>"-Wconversion"
-    <toolset>clang:<cxxflags>"-Wconversion"
-    <toolset>msvc:<warnings-as-errors>on
-    <toolset>gcc:<warnings-as-errors>on
-    <toolset>clang:<warnings-as-errors>on ;
-
 run lightweight_test_test.cpp
   : : : $(pedantic-errors) ;
 run lightweight_test_test.cpp : : :
@@ -194,7 +203,13 @@ run underlying_type.cpp ;
 compile-fail null_deleter_compile_fail_adl.cpp
   : $(warnings-as-errors-off) ;
 
-run fclose_deleter_test.cpp : : : <target-os>windows:<define>_CRT_SECURE_NO_WARNINGS <target-os>windows:<define>_CRT_SECURE_NO_DEPRECATE ;
+run fclose_deleter_test.cpp : : :
+  $(CPP11)
+  <library>/boost/move//boost_move
+  <library>/boost/smart_ptr//boost_smart_ptr
+  <target-os>windows:<define>_CRT_SECURE_NO_WARNINGS
+  <target-os>windows:<define>_CRT_SECURE_NO_DEPRECATE ;
+
 compile-fail fclose_deleter_compile_fail_adl.cpp
   : <target-os>windows:<define>_CRT_SECURE_NO_WARNINGS <target-os>windows:<define>_CRT_SECURE_NO_DEPRECATE $(warnings-as-errors-off) ;
 
@@ -202,7 +217,6 @@ run functor_test.cpp ;
 compile-fail functor_compile_fail_adl.cpp
   : $(warnings-as-errors-off) ;
 
-
 run pointer_traits_pointer_test.cpp ;
 run pointer_traits_element_type_test.cpp ;
 run pointer_traits_difference_type_test.cpp ;
@@ -223,6 +237,8 @@ run empty_value_test.cpp ;
 run empty_value_size_test.cpp ;
 run empty_value_final_test.cpp ;
 run empty_value_constexpr_test.cpp ;
+compile empty_value_nested_test.cpp ;
+compile-fail empty_value_compile_fail_casting.cpp ;
 
 run quick_exit_test.cpp ;
 run-fail quick_exit_fail.cpp ;
@@ -334,33 +350,51 @@ run type_name_test.cpp ;
 
 run snprintf_test.cpp ;
 
-run sv_types_test.cpp ;
-run sv_construct_test.cpp ;
-run sv_iteration_test.cpp ;
-run sv_element_access_test.cpp ;
-run sv_modifiers_test.cpp ;
-run sv_copy_test.cpp ;
-run sv_substr_test.cpp ;
-run sv_compare_test.cpp ;
-run sv_starts_with_test.cpp ;
-run sv_ends_with_test.cpp ;
-run sv_find_test.cpp ;
-run sv_rfind_test.cpp ;
+run sv_types_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_construct_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_iteration_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_element_access_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_modifiers_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_copy_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_substr_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_compare_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_starts_with_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_ends_with_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_find_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_rfind_test.cpp
+  : : : $(pedantic-errors) ;
 run sv_find_first_of_test.cpp
-  : : : <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
+  : : : $(pedantic-errors) <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
 run sv_find_last_of_test.cpp
-  : : : <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
+  : : : $(pedantic-errors) <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
 run sv_find_first_not_of_test.cpp
-  : : : <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
+  : : : $(pedantic-errors) <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
 run sv_find_last_not_of_test.cpp
-  : : : <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
-run sv_contains_test.cpp ;
-run sv_eq_test.cpp ;
-run sv_lt_test.cpp ;
-run sv_stream_insert_test.cpp ;
-run sv_conversion_test.cpp ;
-run sv_conversion_test2.cpp : ;
-run sv_common_reference_test.cpp ;
+  : : : $(pedantic-errors) <toolset>gcc-4.4:<cxxflags>-Wno-type-limits ;
+run sv_contains_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_eq_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_lt_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_stream_insert_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_conversion_test.cpp
+  : : : $(pedantic-errors) ;
+run sv_conversion_test2.cpp : : : <library>/boost/utility//boost_utility ;
+run sv_common_reference_test.cpp
+  : : : $(pedantic-errors) ;
 compile sv_common_reference_test2.cpp ;
 compile sv_windows_h_test.cpp ;
 compile-fail sv_nullptr_fail.cpp
@@ -369,10 +403,13 @@ compile-fail sv_nullptr_fail.cpp
 compile sv_construct_test_cx.cpp ;
 compile sv_construct_test_cx2.cpp ;
 
+run sv_hash_test.cpp : : : $(CPP11) <library>/boost/container_hash//boost_container_hash ;
+
 run span_test.cpp ;
 run span_types_test.cpp ;
 run span_constructible_test.cpp ;
 run span_deduction_guide_test.cpp ;
+run span_constexpr_test.cpp ;
 run as_bytes_test.cpp ;
 run as_writable_bytes_test.cpp ;
 compile span_boost_begin_test.cpp ;
@@ -396,11 +433,15 @@ run memory_resource_test.cpp ;
 run data_test.cpp ;
 run size_test.cpp ;
 
-import ../../config/checks/config : requires ;
-
-local CPP11 = [ requires cxx11_variadic_templates cxx11_template_aliases cxx11_decltype cxx11_constexpr cxx11_noexcept ] ;
-
-local with-serialization = <library>/boost//serialization/<warnings>off $(warnings-as-errors-off) <undefined-sanitizer>norecover:<link>static $(CPP11) ;
+local with-serialization =
+    <library>/boost/serialization//boost_serialization/<warnings>off
+    $(warnings-as-errors-off)
+    <undefined-sanitizer>norecover:<link>static
+    $(CPP11)
+    # Serialization no longer builds under classic MinGW
+    # and <toolset>gcc,<target-os>windows,<address-model>32 fails for some reason
+    <toolset>gcc,<target-os>windows:<build>no
+;
 
 run serialization_nvp_test.cpp : : : $(with-serialization) <undefined-sanitizer>norecover:<build>no ;
 run serialization_split_free_test.cpp : : : $(with-serialization) ;
@@ -419,5 +460,8 @@ run yield_prim_pthread_cancel_test.cpp : ;
 run pointer_in_range_test.cpp ;
 compile pointer_in_range_constexpr_test.cpp ;
 
+run minstd_rand_test.cpp
+  : : : $(pedantic-errors) ;
+
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;

test/cmake_install_test/CMakeLists.txt

@@ -14,4 +14,4 @@ target_link_libraries(quick Boost::core)
 enable_testing()
 add_test(quick quick)
 
-add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
+add_custom_target(check VERBATIM COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)

test/cmake_subdir_test/CMakeLists.txt

@@ -18,4 +18,4 @@ target_link_libraries(quick Boost::core)
 enable_testing()
 add_test(quick quick)
 
-add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
+add_custom_target(check VERBATIM COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)

test/empty_value_compile_fail_casting.cpp

@@ -0,0 +1,20 @@
+// Copyright 2024 Braden Ganetsky
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/empty_value.hpp>
+
+struct empty {};
+
+// This test ensures private inheritance of `boost::empty_value<T>` for empty `T`.
+// With public inheritance, `boost::empty_value<empty>*` could cast to `empty*`.
+void test_empty_not_convertible_to_base()
+{
+    const boost::empty_value<empty> x(boost::empty_init);
+    const empty* x2 = static_cast<const empty*>(&x);
+    (void)x2;
+}
+
+int main()
+{
+}

test/empty_value_nested_test.cpp

@@ -0,0 +1,45 @@
+/*
+Copyright 2024 Braden Ganetsky
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/core/empty_value.hpp>
+
+/*
+Tests workaround for MSVC bug:
+https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025
+*/
+template<class T>
+struct derived
+    : boost::empty_value<T> {
+    typedef typename boost::empty_value<T>::type type;
+    derived(boost::empty_init_t e)
+        : boost::empty_value<T>(e) { }
+};
+
+struct outer {
+    struct inner_empty { };
+    struct inner_non_empty {
+        inner_non_empty()
+            : value() { }
+        int value;
+    };
+};
+
+void test()
+{
+    const boost::empty_value<outer> x1(boost::empty_init);
+    (void)x1;
+    const boost::empty_value<outer::inner_empty> x2(boost::empty_init);
+    (void)x2;
+    const boost::empty_value<outer::inner_non_empty> x3(boost::empty_init);
+    (void)x3;
+    const derived<outer> x4(boost::empty_init);
+    (void)x4;
+    const derived<outer::inner_empty> x5(boost::empty_init);
+    (void)x5;
+    const derived<outer::inner_non_empty> x6(boost::empty_init);
+    (void)x6;
+}

test/minstd_rand_test.cpp

@@ -0,0 +1,38 @@
+// Test for boost/core/detail/minstd_rand.hpp
+//
+// Copyright 2022, 2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/detail/minstd_rand.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/cstdint.hpp>
+
+int main()
+{
+    {
+        boost::detail::minstd_rand rng;
+
+        boost::uint_least32_t r1 = rng(), x1 = 48271;
+        BOOST_TEST_EQ( r1, x1 );
+
+        for( int i = 0; i < 1000; ++i ) rng();
+
+        boost::uint_least32_t r2 = rng(), x2 = 2076422031;
+        BOOST_TEST_EQ( r2, x2 );
+    }
+
+    {
+        boost::detail::minstd_rand rng( 12345 );
+
+        boost::uint_least32_t r1 = rng(), x1 = 595905495;
+        BOOST_TEST_EQ( r1, x1 );
+
+        for( int i = 0; i < 1000; ++i ) rng();
+
+        boost::uint_least32_t r2 = rng(), x2 = 1065162103;
+        BOOST_TEST_EQ( r2, x2 );
+    }
+
+    return boost::report_errors();
+}

test/span_constexpr_test.cpp

@@ -0,0 +1,72 @@
+/*
+Copyright 2025 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/config.hpp>
+#if !defined(BOOST_NO_CXX11_CONSTEXPR)
+#include <boost/core/span.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+constexpr const int array[4]{ 5, 10, 15, 20 };
+
+void test_first()
+{
+    constexpr boost::span<const int> s =
+        boost::span<const int>(array, 4).first(2);
+    BOOST_TEST_EQ(s.data(), &array[0]);
+    BOOST_TEST_EQ(s.size(), 2);
+}
+
+void test_last()
+{
+    constexpr boost::span<const int> s =
+        boost::span<const int>(array, 4).last(2);
+    BOOST_TEST_EQ(s.data(), &array[2]);
+    BOOST_TEST_EQ(s.size(), 2);
+}
+
+void test_subspan()
+{
+    constexpr boost::span<const int> s =
+        boost::span<const int>(array, 4).subspan(1, 2);
+    BOOST_TEST_EQ(s.data(), &array[1]);
+    BOOST_TEST_EQ(s.size(), 2);
+}
+
+void test_index()
+{
+    constexpr const int i = boost::span<const int>(array, 4)[1];
+    BOOST_TEST_EQ(i, 10);
+}
+
+void test_front()
+{
+    constexpr const int i = boost::span<const int>(array, 4).front();
+    BOOST_TEST_EQ(i, 5);
+}
+
+void test_back()
+{
+    constexpr const int i = boost::span<const int>(array, 4).back();
+    BOOST_TEST_EQ(i, 20);
+}
+
+int main()
+{
+    test_first();
+    test_last();
+    test_subspan();
+    test_index();
+    test_front();
+    test_back();
+    return boost::report_errors();
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif

test/sv_find_first_not_of_test.cpp

@@ -494,7 +494,7 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            str[ i ] = static_cast< unsigned char >( i );
+            str[ i ] = static_cast<char>( static_cast< unsigned char >( i ) );
         }
 
         boost::core::string_view sv( str, 256 );
@@ -503,22 +503,22 @@ int main()
 
         std::string str2( sv.data(), sv.size() );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::string str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<char>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), i );
         }
 
         std::reverse( str, str + 256 );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::string str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<char>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), 255 - i );
         }
@@ -538,22 +538,22 @@ int main()
 
         std::wstring str2( sv.data(), sv.size() );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::wstring str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<wchar_t>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), i );
         }
 
         std::reverse( str, str + 256 );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::wstring str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<wchar_t>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), 255 - i );
         }

test/sv_find_first_of_test.cpp

@@ -426,14 +426,14 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            str[ i ] = static_cast< unsigned char >( i );
+            str[ i ] = static_cast<char>( static_cast< unsigned char >( i ) );
         }
 
         boost::core::string_view sv( str, 256 );
 
         for( int i = 0; i < 256; ++i )
         {
-            std::string needle( 12, static_cast< unsigned char >( i ) );
+            std::string needle( 12, static_cast<char>( static_cast< unsigned char >( i ) ) );
             BOOST_TEST_EQ( sv.find_first_of( needle ), i );
         }
 
@@ -441,7 +441,7 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            std::string needle( 12, static_cast< unsigned char >( i ) );
+            std::string needle( 12, static_cast<char>( static_cast< unsigned char >( i ) ) );
             BOOST_TEST_EQ( sv.find_first_of( needle ), 255 - i );
         }
     }

test/sv_find_last_not_of_test.cpp

@@ -494,7 +494,7 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            str[ i ] = static_cast< unsigned char >( i );
+            str[ i ] = static_cast<char>( static_cast< unsigned char >( i ) );
         }
 
         boost::core::string_view sv( str, 256 );
@@ -503,22 +503,22 @@ int main()
 
         std::string str2( sv.data(), sv.size() );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::string str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<char>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_last_not_of( str3 ), i );
         }
 
         std::reverse( str, str + 256 );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::string str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<char>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_last_not_of( str3 ), 255 - i );
         }
@@ -538,22 +538,22 @@ int main()
 
         std::wstring str2( sv.data(), sv.size() );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::wstring str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<wchar_t>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), i );
         }
 
         std::reverse( str, str + 256 );
 
-        for( int i = 0; i < 256; ++i )
+        for( std::size_t i = 0; i < 256; ++i )
         {
             std::wstring str3( str2 );
 
-            str3[ i ] = ~str3[ i ];
+            str3[ i ] = static_cast<wchar_t>( ~str3[ i ] );
 
             BOOST_TEST_EQ( sv.find_first_not_of( str3 ), 255 - i );
         }

test/sv_find_last_of_test.cpp

@@ -444,14 +444,14 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            str[ i ] = static_cast< unsigned char >( i );
+            str[ i ] = static_cast<char>( static_cast< unsigned char >( i ) );
         }
 
         boost::core::string_view sv( str, 256 );
 
         for( int i = 0; i < 256; ++i )
         {
-            std::string needle( 12, static_cast< unsigned char >( i ) );
+            std::string needle( 12, static_cast<char>( static_cast< unsigned char >( i ) ) );
             BOOST_TEST_EQ( sv.find_last_of( needle ), i );
         }
 
@@ -459,7 +459,7 @@ int main()
 
         for( int i = 0; i < 256; ++i )
         {
-            std::string needle( 12, static_cast< unsigned char >( i ) );
+            std::string needle( 12, static_cast<char>( static_cast< unsigned char >( i ) ) );
             BOOST_TEST_EQ( sv.find_last_of( needle ), 255 - i );
         }
     }

test/sv_hash_test.cpp

@@ -0,0 +1,48 @@
+// Copyright 2021-2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/detail/string_view.hpp>
+#include <boost/container_hash/hash.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+#include <string>
+
+template<class T> std::size_t hv( T const& t )
+{
+    return boost::hash<T>()( t );
+}
+
+template<class Ch> void test( Ch const* p )
+{
+    std::basic_string<Ch> s( p );
+    boost::core::basic_string_view<Ch> sv( s );
+
+    BOOST_TEST_EQ( hv( s ), hv( sv ) );
+}
+
+int main()
+{
+    test( "123" );
+    test( L"123" );
+
+#if !defined(BOOST_NO_CXX11_CHAR16_T)
+
+    test( u"123" );
+
+#endif
+
+#if !defined(BOOST_NO_CXX11_CHAR32_T)
+
+    test( U"123" );
+
+#endif
+
+#if defined(__cpp_char8_t) && __cpp_char8_t >= 201811L
+
+    test( u8"123" );
+
+#endif
+
+    return boost::report_errors();
+}

test/type_name_test.cpp

@@ -55,6 +55,13 @@ template<class T1, class T2> struct X
 
 template<class T1, class T2> struct Y;
 
+class W
+{
+public:
+
+    virtual void f() = 0;
+};
+
 enum E1
 {
     e1
@@ -122,6 +129,7 @@ int main()
     TEST(A);
     TEST(B);
     TEST(C);
+    TEST(W);
 
     TEST(E1);
 
@@ -143,6 +151,9 @@ int main()
     TEST(C&);
     TEST(C const&);
 
+    TEST(W const);
+    TEST(W&);
+
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
 
     TEST(B&&);
@@ -156,6 +167,8 @@ int main()
     TEST(C*);
     TEST(C const* volatile*);
 
+    TEST(W volatile*);
+
     TEST(void*);
     TEST(void const* volatile*);
 
@@ -307,6 +320,8 @@ int main()
 
     TEST(std::pair<C, C>);
 
+    TEST(std::pair<W, W>);
+
     TEST(std::pair<void, void>);
     TEST(std::pair<std::pair<void, void>, void>);
 
@@ -336,9 +351,11 @@ int main()
     TEST(X<A const&, B&> volatile&);
 
     TEST(X<C, C>);
+    TEST(X<W, W>);
 
     TEST(Y<A, B>);
     TEST(Y<C, C>);
+    TEST(Y<W, W>);
 
     TEST(X<std::pair<void, void>, void>);