Added a release notes entry for the empty_value fix.

Rename typedef `base` to `core_ev_base`

.drone.jsonnet

@@ -200,31 +200,38 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 32 ASAN",
+        "Linux 23.04 GCC 13 32/64",
         "cppalliance/droneubuntu2304:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32,64' },
         "g++-13-multilib",
     ),
 
     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(
@@ -354,17 +361,24 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 23.10 Clang 17 UBSAN",
+        "Linux 23.10 Clang 17",
         "cppalliance/droneubuntu2310:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '03,11,14,17,20,2b' } + ubsan,
+        { 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",
     ),
 
     macos_pipeline(

.github/workflows/ci.yml

@@ -128,6 +128,13 @@ jobs:
             container: ubuntu:23.04
             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"
@@ -286,15 +293,23 @@ jobs:
           - toolset: clang
             compiler: clang++-17
             cxxstd: "03,11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:23.10
             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++
           - name: UBSAN
@@ -310,15 +325,15 @@ 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
 
     timeout-minutes: 45
     runs-on: ${{matrix.os}}
@@ -611,9 +626,9 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
           - os: macos-12
           - os: macos-13
+          - os: macos-14
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 10
@@ -678,9 +693,9 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
           - os: macos-12
           - os: macos-13
+          - os: macos-14
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 10
@@ -755,9 +770,9 @@ jobs:
         include:
           - os: ubuntu-20.04
           - os: ubuntu-22.04
-          - os: macos-11
           - os: macos-12
           - os: macos-13
+          - os: macos-14
 
     runs-on: ${{matrix.os}}
     timeout-minutes: 20

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>''']]
 

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/type_name.hpp

@@ -346,6 +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 )
@@ -354,6 +356,8 @@ template<> struct tn_holder<wchar_t>
     }
 };
 
+#endif
+
 #if !defined(BOOST_NO_CXX11_CHAR16_T)
 
 template<> struct tn_holder<char16_t>

test/Jamfile.v2

@@ -226,6 +226,8 @@ 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 ;

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;
+}