Bump MSVC < 1950 workarounds to < 1960; still unfixed. Sad!

This prevents the code from erroneously copying the storage which causes
surprising behavior as noted here:
https://github.com/boostorg/compat/issues/23

.drone.jsonnet

@@ -34,7 +34,6 @@ local linux_pipeline(name, image, environment, packages = "", sources = [], arch
                 '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 []) +
             (if packages != "" then [ 'apt-get update', 'apt-get -y install ' + packages ] else []) +
@@ -160,31 +159,24 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 24.04 GCC 14 32 ASAN",
+        "Linux 24.04 GCC 14 32/64 ASAN",
         "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b', ADDRMD: '32' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b', ADDRMD: '32,64' } + asan,
         "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 24.04 GCC 14 64 ASAN",
+        "Linux 24.04 GCC 14 32/64 UBSAN",
         "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b', ADDRMD: '64' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b', ADDRMD: '32,64' } + ubsan,
         "g++-14-multilib",
     ),
 
     linux_pipeline(
-        "Linux 24.04 GCC 14 32 UBSAN",
-        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '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: '11,14,17,20,2b', ADDRMD: '64' } + ubsan,
-        "g++-14-multilib",
+        "Linux 25.10 GCC 15 32/64",
+        "cppalliance/droneubuntu2510:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-15', CXXSTD: '11,14,17,20,23,2c', ADDRMD: '32,64' },
+        "g++-15-multilib",
     ),
 
     linux_pipeline(
@@ -202,40 +194,47 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
     ),
 
     linux_pipeline(
-        "Linux 24.04 Clang 17 UBSAN",
+        "Linux 24.04 Clang 17",
         "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' } + ubsan,
+        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' },
         "clang-17",
     ),
 
     linux_pipeline(
-        "Linux 24.04 Clang 17 ASAN",
+        "Linux 24.04 Clang 18",
         "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' } + asan,
-        "clang-17",
-    ),
-
-    linux_pipeline(
-        "Linux 24.04 Clang 18 UBSAN",
-        "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '11,14,17,20,2b' } + ubsan,
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '11,14,17,20,2b' },
         "clang-18",
     ),
 
     linux_pipeline(
-        "Linux 24.04 Clang 18 ASAN",
+        "Linux 24.04 Clang 19",
         "cppalliance/droneubuntu2404:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '11,14,17,20,2b' } + asan,
-        "clang-18",
-    ),
-
-    linux_pipeline(
-        "Linux 24.10 Clang 19",
-        "cppalliance/droneubuntu2410:1",
         { TOOLSET: 'clang', COMPILER: 'clang++-19', CXXSTD: '11,14,17,20,2b' },
         "clang-19",
     ),
 
+    linux_pipeline(
+        "Linux 24.04 Clang 20 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-20', CXXSTD: '11,14,17,20,23,2c' } + ubsan,
+        "clang-20",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 Clang 20 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-20', CXXSTD: '11,14,17,20,23,2c' } + asan,
+        "clang-20",
+    ),
+
+    linux_pipeline(
+        "Linux 25.10 Clang 21",
+        "cppalliance/droneubuntu2510:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-21', CXXSTD: '11,14,17,20,23,2c' },
+        "clang-21",
+    ),
+
     macos_pipeline(
         "MacOS 10.15 Xcode 12.2 UBSAN",
         { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '11,14,1z' } + ubsan,
@@ -258,6 +257,18 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
         xcode_version = "13.4.1", osx_version = "monterey", arch = "arm64",
     ),
 
+    macos_pipeline(
+        "MacOS 14 Xcode 16.2.0 UBSAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,17,20,2b' } + ubsan,
+        xcode_version = "16.2.0", osx_version = "sonoma", arch = "arm64",
+    ),
+
+    macos_pipeline(
+        "MacOS 14 Xcode 16.2.0 ASAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,17,20,2b' } + asan,
+        xcode_version = "16.2.0", osx_version = "sonoma", arch = "arm64",
+    ),
+
     windows_pipeline(
         "Windows VS2015 msvc-14.0",
         "cppalliance/dronevs2015",
@@ -281,4 +292,10 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
         "cppalliance/dronevs2022:1",
         { TOOLSET: 'msvc-14.3', CXXSTD: '14,17,20,latest' },
     ),
+
+    windows_pipeline(
+        "Windows VS2026 msvc-14.5",
+        "cppalliance/dronevs2026:1",
+        { TOOLSET: 'msvc-14.5', CXXSTD: '14,17,20,latest' },
+    ),
 ]

.github/workflows/ci.yml

@@ -183,18 +183,24 @@ jobs:
           - toolset: clang
             compiler: clang++-20
             cxxstd: "03,11,14,17,20,23,2c"
-            container: ubuntu:25.04
+            container: ubuntu:24.04
             os: ubuntu-latest
             install: clang-20
           - toolset: clang
-            cxxstd: "03,11,14,17,20,2b"
-            os: macos-13
+            compiler: clang++-21
+            cxxstd: "03,11,14,17,20,23,2c"
+            container: ubuntu:25.10
+            os: ubuntu-latest
+            install: clang-21
           - toolset: clang
             cxxstd: "03,11,14,17,20,2b"
             os: macos-14
           - toolset: clang
-            cxxstd: "03,11,14,17,20,2b"
+            cxxstd: "03,11,14,17,20,23,2c"
             os: macos-15
+          - toolset: clang
+            cxxstd: "03,11,14,17,20,23,2c"
+            os: macos-26
 
     runs-on: ${{matrix.os}}
 
@@ -321,9 +327,9 @@ jobs:
         include:
           - os: ubuntu-22.04
           - os: ubuntu-24.04
-          - os: macos-13
           - os: macos-14
           - os: macos-15
+          - os: macos-26
 
     runs-on: ${{matrix.os}}
 
@@ -370,9 +376,9 @@ jobs:
         include:
           - os: ubuntu-22.04
           - os: ubuntu-24.04
-          - os: macos-13
           - os: macos-14
           - os: macos-15
+          - os: macos-26
 
     runs-on: ${{matrix.os}}
 
@@ -429,9 +435,9 @@ jobs:
         include:
           - os: ubuntu-22.04
           - os: ubuntu-24.04
-          - os: macos-13
           - os: macos-14
           - os: macos-15
+          - os: macos-26
 
     runs-on: ${{matrix.os}}
 

doc/compat/changelog.adoc

@@ -11,7 +11,6 @@ https://www.boost.org/LICENSE_1_0.txt
 ## Changes in 1.90.0
 
 * Added `to_underlying.hpp` (contributed by Braden Ganetsky.)
-* Extracted `nontype_t` to its own public header `nontype.hpp` and added `nontype`.
 
 ## Changes in 1.89.0
 

doc/compat/function_ref.adoc

@@ -39,8 +39,6 @@ for (auto fn : fns) {
 ## Synopsis
 
 ```cpp
-#include <boost/compat/nontype.hpp>
-
 namespace boost
 {
 namespace compat

doc/compat/reference.adoc

@@ -12,7 +12,6 @@ include::invoke.adoc[]
 include::latch.adoc[]
 include::mem_fn.adoc[]
 include::move_only_function.adoc[]
-include::nontype.adoc[]
 include::shared_lock.adoc[]
 include::to_array.adoc[]
 include::to_underlying.adoc[]

include/boost/compat/function_ref.hpp

@@ -5,7 +5,7 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/compat/nontype.hpp>
+#include <boost/compat/detail/nontype.hpp>
 #include <boost/compat/invoke.hpp>
 #include <boost/compat/type_traits.hpp>
 

include/boost/compat/move_only_function.hpp

@@ -247,7 +247,7 @@ bool is_nullary_arg( F f )
 template<bool NoEx, class R, class ...Args>
 struct mo_invoke_function_holder
 {
-    static R invoke_function( storage s, Args&&... args) noexcept( NoEx )
+    static R invoke_function( storage const& s, Args&&... args) noexcept( NoEx )
     {
         auto f = reinterpret_cast<R(*)( Args... )>( s.pfn_ );
         return compat::invoke_r<R>( f, std::forward<Args>( args )... );
@@ -257,7 +257,7 @@ struct mo_invoke_function_holder
 template<ref_quals RQ, bool Const, bool NoEx, class F, class R, class ...Args>
 struct mo_invoke_object_holder
 {
-    static R invoke_object( storage s, Args&&... args ) noexcept( NoEx )
+    static R invoke_object( storage const& s, Args&&... args ) noexcept( NoEx )
     {
         using T = remove_reference_t<F>;
         using cv_T = conditional_t<Const, add_const_t<T>, T>;
@@ -274,7 +274,7 @@ struct mo_invoke_object_holder
 template<ref_quals RQ, bool Const, bool NoEx, class F, class R, class ...Args>
 struct mo_invoke_local_holder
 {
-    static R invoke_local( storage s, Args&&... args ) noexcept( NoEx )
+    static R invoke_local( storage const& s, Args&&... args ) noexcept( NoEx )
     {
         using T = remove_reference_t<F>;
         using cv_T = conditional_t<Const, add_const_t<T>, T>;
@@ -285,7 +285,7 @@ struct mo_invoke_local_holder
             >
         >;
 
-        return compat::invoke_r<R>( static_cast<cv_ref_T>( *static_cast<cv_T*>( s.addr() ) ), std::forward<Args>( args )... );
+        return compat::invoke_r<R>( static_cast<cv_ref_T>( *static_cast<cv_T*>( const_cast<storage&>( s ).addr() ) ), std::forward<Args>( args )... );
     }
 };
 
@@ -485,9 +485,9 @@ struct move_only_function_base
 
     detail::storage s_;
 #if defined(__cpp_noexcept_function_type)
-    R ( *invoke_ )( detail::storage, Args&&... ) noexcept( NoEx ) = nullptr;
+    R ( *invoke_ )( detail::storage const&, Args&&... ) noexcept( NoEx ) = nullptr;
 #else
-    R ( *invoke_ )( detail::storage, Args&&... ) = nullptr;
+    R ( *invoke_ )( detail::storage const&, Args&&... ) = nullptr;
 #endif
     void ( *manager_ )( op_type, detail::storage&, detail::storage* ) = &manage_empty;
 };

test/bind_back_md_constexpr_test.cpp

@@ -39,7 +39,7 @@ int main()
         BOOST_TEST_EQ( boost::compat::bind_back( &X::m, &x )(), -1 );
     }
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1950)
+#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1960)
 
     {
         BOOST_TEST_EQ( boost::compat::bind_back( &X::m, Y() )(), -1 );

test/bind_front_md_constexpr_test.cpp

@@ -39,7 +39,7 @@ int main()
         BOOST_TEST_EQ( boost::compat::bind_front( &X::m, &x )(), -1 );
     }
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1950)
+#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1960)
 
     {
         BOOST_TEST_EQ( boost::compat::bind_front( &X::m, Y() )(), -1 );

test/invoke_md_constexpr_test.cpp

@@ -29,7 +29,7 @@ int main()
         BOOST_TEST_EQ( boost::compat::invoke( &X::m, &x ), -1 );
     }
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1950)
+#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1960)
     {
         BOOST_TEST_EQ( boost::compat::invoke( &X::m, Y() ), -1 );
 

test/invoke_r_md_constexpr_test.cpp

@@ -36,7 +36,7 @@ int main()
 #endif
     }
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1950)
+#if !BOOST_WORKAROUND(BOOST_MSVC, >= 1920 && BOOST_MSVC < 1960)
     {
         constexpr Y y = {};
 

test/move_only_function_test.cpp

@@ -13,7 +13,8 @@
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-#include <functional>
+#include <array>
+#include <cstdint>
 #include <memory>
 #include <type_traits>
 
@@ -845,11 +846,39 @@ static void test_conv()
     }
 }
 
+static void test_mutable_lambda()
+{
+    {
+        // Within SBO limits.
+        int captured = 0;
+        move_only_function<int()> func = [captured]() mutable { return ++captured; };
+
+        BOOST_TEST_EQ( func(), 1 );
+        BOOST_TEST_EQ( func(), 2 );
+
+        move_only_function<int()> func2(std::move(func));
+        BOOST_TEST_EQ( func2(), 3 );
+    }
+
+    {
+        // Too large for SBO.
+        std::array<std::uint8_t, 256> captured = {{}};
+        move_only_function<int()> func = [captured]() mutable { return ++captured[0]; };
+
+        BOOST_TEST_EQ( func(), 1 );
+        BOOST_TEST_EQ( func(), 2 );
+
+        move_only_function<int()> func2(std::move(func));
+        BOOST_TEST_EQ( func2(), 3 );
+    }
+}
+
 int main()
 {
     test_call();
     test_traits();
     test_conv();
+    test_mutable_lambda();
 
     return boost::report_errors();
 }

test/nontype_test.cpp

@@ -2,7 +2,7 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/compat/nontype.hpp>
+#include <boost/compat/detail/nontype.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 #include <boost/config/pragma_message.hpp>