Sync from upstream.

.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",
+        "Linux 24.04 GCC 14 32 ASAN",
-        "cppalliance/droneubuntu2304:1",
+        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + asan,
-        "g++-13-multilib",
+        "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 32 UBSAN",
+        "Linux 24.04 GCC 14 64 ASAN",
-        "cppalliance/droneubuntu2304:1",
+        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + ubsan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + asan,
-        "g++-13-multilib",
+        "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 23.04 GCC 13 64 UBSAN",
+        "Linux 24.04 GCC 14 32 UBSAN",
-        "cppalliance/droneubuntu2304:1",
+        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + ubsan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + ubsan,
-        "g++-13-multilib",
+        "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",
+        "Linux 24.04 Clang 18 UBSAN",
-        "cppalliance/droneubuntu2310:1",
+        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '03,11,14,17,20,2b' } + asan,
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '03,11,14,17,20,2b' } + ubsan,
-        "clang-17",
+        "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:
+            cxxflags: -stdlib=libc++
-              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main"
+            linkflags: -stdlib=libc++
-            source_keys:
+          - toolset: clang
-              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+            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

include/boost/core/empty_value.hpp

@@ -96,8 +96,10 @@ 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.
+/*
-// See https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025
+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>
@@ -138,10 +140,10 @@ 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> base;
+    typedef detail::empty_value_base<T> empty_base_;
 #else
     : T {
-    typedef T base;
+    typedef T empty_base_;
 #endif
 
 public:
@@ -154,26 +156,26 @@ public:
 #endif
 
     BOOST_CONSTEXPR empty_value(boost::empty_init_t)
-        : base() { }
+        : 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)
-        : base(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)
-        : base(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)
-        : base(value) { }
+        : empty_base_(value) { }
 
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U& value)
-        : base(value) { }
+        : empty_base_(value) { }
 #endif
 
     BOOST_CONSTEXPR const T& get() const BOOST_NOEXCEPT {

test/Jamfile.v2

@@ -229,6 +229,7 @@ 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 ;

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/empty_value_test.cpp

@@ -63,40 +63,6 @@ void test_type()
     BOOST_TEST(v2.get().value() == 6);
 }
 
-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_derived_compile()
-{
-    // This is testing the workaround to an MSVC bug when T is a nested class.
-    // See https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025
-
-    const boost::empty_value<outer> x1(boost::empty_init);
-    const boost::empty_value<outer::inner_empty> x2(boost::empty_init);
-    const boost::empty_value<outer::inner_non_empty> x3(boost::empty_init);
-    const derived<outer> x4(boost::empty_init);
-    const derived<outer::inner_empty> x5(boost::empty_init);
-    const derived<outer::inner_non_empty> x6(boost::empty_init);
-
-    (void)x1;
-    (void)x2;
-    (void)x3;
-    (void)x4;
-    (void)x5;
-    (void)x6;
-}
-
 int main()
 {
     test_int();