Update copyright years

Update CI (#227 )
Bump actions/checkout from 2 to 6 (#226 )
2026-01-19 04:22:13 +00:00 · 2026-01-04 11:26:11 +03:00 · 2025-12-31 14:48:17 +03:00 · 2025-12-31 14:19:43 +03:00 · 2025-12-24 20:19:28 +03:00 · 2025-10-28 19:40:55 +03:00
126 changed files with 1031 additions and 442 deletions
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -0,0 +1,11 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+        interval: "weekly"
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,10 +17,10 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - toolset: gcc-14
+          - toolset: gcc-14  # Do not remove! It is the only toolset that tests CMake tests down below
            cxxstd: "03,11,14,17,20"
            os: ubuntu-24.04
-          - toolset: gcc-12 # Do not remove! It is the only toolset that tests misc/strip_boost_namespace.sh
+          - toolset: gcc-12
            cxxstd: "03,11,14,17,2a"
            os: ubuntu-22.04
            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
@@ -38,25 +38,21 @@ jobs:
            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
            linkflags: "linkflags=--coverage -lasan -lubsan"
            gcov_tool: "gcov-10"
-          - toolset: gcc-9
-            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-22.04
-            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
-            linkflags: "linkflags=--coverage -lasan -lubsan"
-            gcov_tool: "gcov-9"
          - toolset: clang-15
            cxxstd: "03,11,14,17,20"
            os: ubuntu-22.04
-          # - toolset: clang
-          #   cxxstd: "03,11,14,17,2a"
-          #   os: macos-10.15
-          #   cxxflags: "cxxflags=-fsanitize=address,undefined -fno-sanitize-recover=undefined"
-          #   linkflags: "linkflags=-fsanitize=address,undefined"
+          - toolset: clang-18
+            cxxstd: "03,11,14,17,20,23"
+            os: ubuntu-24.04
+          - toolset: clang-19   # tests misc/strip_boost_namespace.sh and modules
+            cxxstd: "20,23"
+            os: ubuntu-24.04
+            install: clang-19 llvm-19 libclang-rt-19-dev libc++-19-dev libc++abi-19-dev clang-tools-19

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6

      - name: Install packages
        if: matrix.install
@@ -84,17 +80,54 @@ jobs:
          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
          python tools/boostdep/depinst/depinst.py --include benchmark --include example --include examples --include tools --git_args "--depth 10 --jobs 3" $LIBRARY
          ./bootstrap.sh
-          ./b2 -d0 headers
-          ./b2 variant=debug tools/inspect/build
+          ./b2 variant=debug tools/inspect
+
+      - name: Run CMake tests
+        if: ${{matrix.toolset == 'gcc-14'}}
+        run: |
+          cd ../boost-root/
+          mkdir __build
+          cd __build
+          cmake -DBUILD_TESTING=1 -DBOOST_INCLUDE_LIBRARIES=pfr -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_C_COMPILER=gcc-14 ..
+          cmake --build . --target tests
+          ctest --output-on-failure --no-tests=error
+          cd ..
+          rm -rf __build
+
+      - name: Run modules tests
+        if: false
+        # if: ${{matrix.toolset == 'clang-19'}}
+        run: |
+          cd ../boost-root/libs/pfr
+          mkdir build_module
+          cd build_module
+          cmake -DBUILD_TESTING=1 -DBOOST_USE_MODULES=1 -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS=-stdlib=libc++ -DCMAKE_EXE_LINKER_FLAGS=-stdlib=libc++ -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ../test/cmake_subdir_test
+          cmake --build .
+          ctest -V
+          cd ..
+          rm -rf build_module
+
+      - name: Run modules tests wihtout 'import std;'
+        if: ${{matrix.toolset == 'clang-19'}}
+        run: |
+          cd ../boost-root/libs/pfr
+          mkdir build_module
+          cd build_module
+          cmake -DBOOST_USE_MODULES=1 -DBUILD_TESTING=1 -GNinja -DCMAKE_CXX_COMPILER=clang++-19 ../test/cmake_subdir_test
+          cmake --build .
+          ctest -V
+          cd ..
+          rm -rf build_module

      - name: Run tests
        run: |
          cd ../boost-root
+          ./b2 -d0 headers
          ./b2 libs/$LIBRARY/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} variant=debug,release "${{matrix.cxxflags}}" "${{matrix.linkflags}}" "${{matrix.launcher}}"
          dist/bin/inspect libs/$LIBRARY

      - name: Test boost namespace stripping
-        if: ${{matrix.toolset == 'gcc-12'}}
+        if: ${{matrix.toolset == 'clang-19'}}
        run: ../boost-root/libs/$LIBRARY/misc/strip_boost_namespace.sh

      - name: Prepare coverage data
@@ -130,30 +163,31 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - toolset: msvc-14.0
-            cxxstd: "14,latest"
-            addrmd: 32,64
-            os: windows-2019
+          - toolset: msvc-14.3        # tests CMake tests down below, does not run b2 tests
+            cxxstd: "14,17,20,latest"
+            addrmd: 64
+            os: windows-2025
            threads: "-j3"
          - toolset: gcc
            cxxstd: "03,11,14,17,2a"
            addrmd: 64
-            os: windows-2019
+            os: windows-2025
            threads: "-j3"
-          - toolset: msvc-14.3
+          - toolset: msvc-14.3  # tests CMake tests down below
            cxxstd: "20,latest"
            addrmd: 64
            os: windows-2022
            threads: "-j1"
-          - toolset: clang-win
-            cxxstd: "14,17,2a,latest"
-            addrmd: 32,64
-            os: windows-2022
+            # Fails with "Unexpected compiler version, expected Clang 19.0.0 or newer."
+            # - toolset: clang-win
+            #   cxxstd: "14,17,2a,latest"
+            #   addrmd: 32,64
+            #   os: windows-2022

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6

      - name: Setup Boost
        shell: cmd
@@ -175,12 +209,58 @@ jobs:
          git submodule update --init --depth 10 --jobs 2 tools/boostdep
          python tools/boostdep/depinst/depinst.py --include benchmark --include example --include examples --include tools --git_args "--jobs 3" %LIBRARY%
          cmd /c bootstrap
-          b2 -d0 headers
+
+      - name: Run CMake tests
+        if: ${{matrix.toolset == 'msvc-14.3'}}
+        shell: cmd
+        run: |
+          choco install --no-progress ninja
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/
+          mkdir __build
+          cd __build
+          cmake -DBUILD_TESTING=1 -DBOOST_INCLUDE_LIBRARIES=pfr ..
+          cmake --build . --target tests --config Debug
+          ctest --output-on-failure --no-tests=error -C Debug
+          cd ..
+          rm -rf __build
+
+      - name: Run modules tests
+        if: false
+        # if: ${{matrix.toolset == 'msvc-14.3'}}
+        shell: cmd
+        run: |
+          choco install --no-progress ninja
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/libs/pfr
+          mkdir build_module
+          cd build_module
+          cmake -DBOOST_USE_MODULES=1 -DBUILD_TESTING=1 -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ../test/cmake_subdir_test
+          cmake --build .
+          ctest --no-tests=error -V
+          cd ..
+          rm -rf build_module
+
+      - name: Run modules tests wihtout 'import std;'
+        if: ${{matrix.toolset == 'msvc-14.3'}}
+        shell: cmd
+        run: |
+          choco install --no-progress ninja
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/libs/pfr
+          mkdir build_module
+          cd build_module
+          cmake -DBOOST_USE_MODULES=1 -DBUILD_TESTING=1 -DCMAKE_CXX_STANDARD=20 -G Ninja ../test/cmake_subdir_test
+          cmake --build .
+          ctest --no-tests=error -V
+          cd ..
+          rm -rf build_module

      - name: Run tests
        shell: cmd
        run: |
          cd ../boost-root
+          b2 -d0 headers
          b2 ${{matrix.threads}} libs/%LIBRARY%/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} address-model=${{matrix.addrmd}} variant=debug,release

  finish:
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,23 +1,48 @@
 # Copyright 2020 Peter Dimov
-# Copyright (c) 2016-2025 Antony Polukhin
+# Copyright (c) 2016-2026 Antony Polukhin
 #
 # Distributed under the Boost Software License, Version 1.0.
 # https://www.boost.org/LICENSE_1_0.txt

-cmake_minimum_required(VERSION 3.5...3.16)
+cmake_minimum_required(VERSION 3.5...3.31)

 project(boost_pfr VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)

-add_library(boost_pfr INTERFACE)
+if (BOOST_USE_MODULES)
+    add_library(boost_pfr)
+    target_sources(boost_pfr PUBLIC
+        FILE_SET modules_public TYPE CXX_MODULES FILES modules/boost_pfr.cppm
+    )
+
+    target_compile_features(boost_pfr PUBLIC cxx_std_20)
+    target_compile_definitions(boost_pfr PUBLIC BOOST_USE_MODULES)
+    if (CMAKE_CXX_COMPILER_IMPORT_STD)
+        target_compile_definitions(boost_pfr PRIVATE BOOST_PFR_USE_STD_MODULE)
+        message(STATUS "Using `import std;`")
+    else()
+        message(STATUS "`import std;` is not available")
+    endif()
+    target_include_directories(boost_pfr PUBLIC include)
+else()
+    add_library(boost_pfr INTERFACE)
+    target_include_directories(boost_pfr INTERFACE include)
+endif()
+
 add_library(Boost::pfr ALIAS boost_pfr)

-target_include_directories(boost_pfr INTERFACE include)
-
-if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.28.0" AND BUILD_MODULE)
-    add_subdirectory(module)
-endif()
-
+enable_testing()
 if (BUILD_TESTING AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/test/CMakeLists.txt")
-  add_subdirectory(test)
+    add_subdirectory(test)
+endif()
+
+if (BOOST_USE_MODULES AND BUILD_TESTING)
+    add_executable(boost_pfr_module_usage modules/usage_sample.cpp)
+    target_link_libraries(boost_pfr_module_usage PRIVATE Boost::pfr)
+    add_test(NAME boost_pfr_module_usage COMMAND boost_pfr_module_usage)
+
+    # Make sure that mixing includes and imports is fine for different TU
+    add_executable(boost_pfr_module_usage_mu modules/usage_test_mu1.cpp modules/usage_test_mu2.cpp)
+    target_link_libraries(boost_pfr_module_usage_mu PRIVATE Boost::pfr)
+    add_test(NAME boost_pfr_module_usage_mu COMMAND boost_pfr_module_usage_mu)
 endif()

--- a/README.md
+++ b/README.md
@@ -10,8 +10,8 @@ For a version of the library without `boost::` namespace see [PFR](https://githu

 Branches        | Build         | Tests coverage | More info
 ----------------|-------------- | -------------- |-----------
-Develop:        | [![CI](https://github.com/boostorg/pfr/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/pfr/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/0mavmnkdmltcdmqa/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/pfr/branch/develop) | [![Coverage Status](https://coveralls.io/repos/github/apolukhin/magic_get/badge.png?branch=develop)](https://coveralls.io/github/apolukhin/magic_get?branch=develop) | [details...](https://www.boost.org/development/tests/develop/developer/pfr.html)
-Master:         | [![CI](https://github.com/boostorg/pfr/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/pfr/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/0mavmnkdmltcdmqa/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/pfr/branch/master) | [![Coverage Status](https://coveralls.io/repos/github/apolukhin/magic_get/badge.png?branch=master)](https://coveralls.io/github/apolukhin/magic_get?branch=master) | [details...](https://www.boost.org/development/tests/master/developer/pfr.html)
+Develop:        | [![CI](https://github.com/boostorg/pfr/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/pfr/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/0mavmnkdmltcdmqa/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/pfr/branch/develop) | [![Coverage Status](https://coveralls.io/repos/github/apolukhin/magic_get/badge.png?branch=develop)](https://coveralls.io/github/apolukhin/magic_get?branch=develop) | [details...](https://regression.boost.io/develop/developer/pfr.html)
+Master:         | [![CI](https://github.com/boostorg/pfr/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/pfr/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/0mavmnkdmltcdmqa/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/pfr/branch/master) | [![Coverage Status](https://coveralls.io/repos/github/apolukhin/magic_get/badge.png?branch=master)](https://coveralls.io/github/apolukhin/magic_get?branch=master) | [details...](https://regression.boost.io/master/developer/pfr.html)

 [Latest developer documentation](https://www.boost.org/doc/libs/develop/doc/html/boost_pfr.html)

--- a/doc/Jamfile.v2
+++ b/doc/Jamfile.v2
@@ -55,9 +55,8 @@ boostbook pfr-doc
        pfr.qbk
    :
        <dependency>autodoc_pfr
-        <xsl:param>boost.root=https://www.boost.org/doc/libs/1_81_0
-        #<xsl:param>boost.root=../../../.
-        <xml:param>html.stylesheet=../../../../doc/src/boostbook.css
+        #<xsl:param>boost.root=https://www.boost.org/doc/libs/1_88_0
+        <xsl:param>boost.root=../../../..
    ;

 ###############################################################################
--- a/doc/pfr.qbk
+++ b/doc/pfr.qbk
@@ -1,7 +1,7 @@
 [library Boost.PFR
    [quickbook 1.6]
-    [version 2.2]
-    [copyright 2016-2025 Antony Polukhin]
+    [version 2.3]
+    [copyright 2016-2026 Antony Polukhin]
    [category Language Features Emulation]
    [license
        Distributed under the Boost Software License, Version 1.0.
@@ -501,6 +501,7 @@ Boost.PFRs extraction of field name works with only `SimpleAggregate` types.
 By default Boost.PFR [*auto-detects your compiler abilities] and automatically defines the configuration macro into appropriate values. If you wish to override that behavior, just define:
 [table:linkmacro Macros
    [[Macro name] [Effect]]
+    [[*BOOST_PFR_USE_CPP26*] [Define to `1` if you wish to override Boost.PFR choice and use C++26 variadic structured bindings for reflection. Define to `0` to override Boost.PFR choice and disable C++26 variadic structured bindings usage.]]
    [[*BOOST_PFR_USE_CPP17*] [Define to `1` if you wish to override Boost.PFR choice and use C++17 structured bindings for reflection. Define to `0` to override Boost.PFR choice and disable C++17 structured bindings usage.]]
    [[*BOOST_PFR_USE_LOOPHOLE*] [Define to `1` if you wish to override Boost.PFR choice and exploit [@http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#2118 CWG 2118] for reflection. Define to `0` to override Boost.PFR choice and disable CWG 2118 usage.]]
    [[*BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE*] [Define to `0` if you are hit by the template instantiation depth issues with `std::make_integer_sequence` and wish to use Boost.PFR version of that metafunction. Define to `1` to override Boost.PFR detection logic. ]]
@@ -554,34 +555,34 @@ parameters provided to `BOOST_PFR_CORE_NAME_PARSING` macro [*and] the initial ou

 [section PFR as a C++20 module]

-[caution C++20 PFR module support is on early stage, targets and flags may change in the future]
+[caution C++20 PFR module support is on early stage, targets, flags and behavior may change in the future]

-If using CMake of version 3.28.0 or higher define CMake option `-DBUILD_MODULE=1`
-to make the `Boost::pfr_module` and `Boost::pfr_module_migration` libraries
-available. With `Boost::pfr_module` C++20 module Boost.PFR could be used:
+If using modern CMake define CMake option `-DBOOST_USE_MODULES=1` to build a C++20 module and
+make the `Boost::pfr` CMake target provide it. After that an explicit usage of C++20 module `boost.pfr` is allowed:

-[import ../module/usage_sample.cpp]
+[import ../modules/usage_sample.cpp]
 [pfr_module_example]

-The `Boost::pfr_module_migration` CMake target gives an ability to
-mix includes and imports of the PFR library in different translation units.
+The `Boost::pfr` CMake target gives an ability to mix includes and imports of the PFR library in different translation units. Moreover,
+if `BOOST_USE_MODULES` macro is defined then all the `boost/pfr/...` includes implicitly do `import boost.pfr;` to give all the
+benifits of modules without changing the existing code.

-If not using CMake, then the module could be build manually from the
-`module/pfr.cppm` file. If mixing of includes in imports is desired, additionally
-define `BOOST_PFR_ATTACH_TO_GLOBAL_MODULE` preprocessor macro to attach all the
-module entities to a global module and avoid ODR issues.
+[note For better compile times make sure that `import std;` is available when building the `boost.pfr` module (in CMake logs there should be
+      a 'Using `import std;`' message). ]

-For manual module build the following commands could be used for clang compiler:
+If not using CMake, then the module could be build manually from the `modules/boost_pfr.cppm` file.
+
+For manual module build the following commands can be used for clang compiler:

 ```
 cd pfr/module
-clang++ -I ../include -std=c++20 --precompile -x c++-module pfr.cppm
+clang++ -I ../include -std=c++20 --precompile -x c++-module boost_pfr.cppm
 ```

 After that, the module could be used in the following way:

 ```
-clang++ -std=c++20 -fmodule-file=pfr.pcm pfr.pcm usage_sample.cpp
+clang++ -std=c++20 -fmodule-file=boost_pfr.pcm boost_pfr.pcm usage_sample.cpp
 ```

 [endsect]
@@ -593,16 +594,18 @@ clang++ -std=c++20 -fmodule-file=pfr.pcm pfr.pcm usage_sample.cpp
 Short description:

 # at compile-time: use aggregate initialization to detect fields count in user-provided structure
-    * [*BOOST_PFR_USE_CPP17 == 1]:
+    * [*BOOST_PFR_USE_CPP26 == 1]:
+        # at compile-time: structured bindings are used to decompose a type `T` to known variadic amount of fields
+    * [*BOOST_PFR_USE_CPP26 == 0 && BOOST_PFR_USE_CPP17 == 1]:
        # at compile-time: structured bindings are used to decompose a type `T` to known amount of fields
-    * [*BOOST_PFR_USE_CPP17 == 0 && BOOST_PFR_USE_LOOPHOLE == 1]:
+    * [*BOOST_PFR_USE_CPP26 == 0 && BOOST_PFR_USE_CPP17 == 0 && BOOST_PFR_USE_LOOPHOLE == 1]:
        # at compile-time: use aggregate initialization to detect fields count in user-provided structure
        # at compile-time: make a structure that is convertible to anything and remember types it has been converted to during aggregate initialization of user-provided structure
        # at compile-time: using knowledge from previous steps create a tuple with exactly the same layout as in user-provided structure
        # at compile-time: find offsets for each field in user-provided structure using the tuple from previous step
        # at run-time: get pointer to each field, knowing the structure address and each field offset
        # at run-time: a tuple of references to fields is returned => all the tuple methods are available for the structure
-    * [*BOOST_PFR_USE_CPP17 == 0 && BOOST_PFR_USE_LOOPHOLE == 0]:
+    * [*BOOST_PFR_USE_CPP26 == 0 && BOOST_PFR_USE_CPP17 == 0 && BOOST_PFR_USE_LOOPHOLE == 0]:
        # at compile-time: let `I` be is an index of current field, it equals 0
        # at run-time: `T` is constructed and field `I` is aggregate initialized using a separate instance of structure that is convertible to anything [note Additional care is taken to make sure that all the information about `T` is available to the compiler and that operations on `T` have no side effects, so the compiler can optimize away the unnecessary temporary objects.]
        # at compile-time: `I += 1`
--- a/example/get.cpp
+++ b/example/get.cpp
@@ -1,4 +1,4 @@
-// Copyright 2016-2025 Antony Polukhin
+// Copyright 2016-2026 Antony Polukhin

 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt
--- a/example/motivating_example0.cpp
+++ b/example/motivating_example0.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/example/quick_examples.cpp
+++ b/example/quick_examples.cpp
@@ -1,4 +1,4 @@
-// Copyright 2016-2025 Antony Polukhin
+// Copyright 2016-2026 Antony Polukhin

 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt
--- a/example/sample_printing.cpp
+++ b/example/sample_printing.cpp
@@ -1,4 +1,4 @@
-// Copyright 2016-2025 Antony Polukhin
+// Copyright 2016-2026 Antony Polukhin

 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt
--- a/include/boost/pfr.hpp
+++ b/include/boost/pfr.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/include/boost/pfr/config.hpp
+++ b/include/boost/pfr/config.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 // Copyright (c) 2022 Denis Mikhailov
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -8,10 +8,14 @@
 #define BOOST_PFR_CONFIG_HPP
 #pragma once

-#if __cplusplus >= 201402L || (defined(_MSC_VER) && defined(_MSVC_LANG) && _MSC_VER > 1900)
+#if !defined(BOOST_USE_MODULES) && (__cplusplus >= 201402L || (defined(_MSC_VER) && defined(_MSVC_LANG) && _MSC_VER > 1900))
 #include <type_traits> // to get non standard platform macro definitions (__GLIBCXX__ for example)
 #endif

+#if defined(BOOST_USE_MODULES) || __cplusplus >= 202002L
+#include <version>
+#endif
+
 /// \file boost/pfr/config.hpp
 /// Contains all the macros that describe Boost.PFR configuration, like BOOST_PFR_ENABLED
 ///
@@ -49,6 +53,14 @@
 #   endif
 #endif

+#ifndef BOOST_PFR_USE_CPP26
+#if __cpp_structured_bindings >= 202411L && __cpp_lib_forward_like >= 202207L
+#define BOOST_PFR_USE_CPP26 1
+#else
+#define BOOST_PFR_USE_CPP26 0
+#endif
+#endif
+
 #ifndef BOOST_PFR_USE_CPP17
 #   ifdef __cpp_structured_bindings
 #       define BOOST_PFR_USE_CPP17 1
@@ -63,15 +75,17 @@
 #   endif
 #endif

-#if (!BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_LOOPHOLE)
+#if (!BOOST_PFR_USE_CPP26 && !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_LOOPHOLE)
 #   if (defined(_MSC_VER) && _MSC_VER < 1916) ///< in Visual Studio 2017 v15.9 PFR library with classic engine normally works
 #      define BOOST_PFR_NOT_SUPPORTED 1
 #   endif
 #endif

 #ifndef BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE
+#   if defined(BOOST_USE_MODULES)
+#       define BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE 1
 // Assume that libstdc++ since GCC-7.3 does not have linear instantiation depth in std::make_integral_sequence
-#   if defined( __GLIBCXX__) && __GLIBCXX__ >= 20180101
+#   elif defined( __GLIBCXX__) && __GLIBCXX__ >= 20180101
 #       define BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE 1
 #   elif defined(_MSC_VER)
 #       define BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE 1
@@ -145,12 +159,16 @@

 #undef BOOST_PFR_NOT_SUPPORTED

-#ifndef BOOST_PFR_BEGIN_MODULE_EXPORT
+#ifdef BOOST_PFR_INTERFACE_UNIT
+#   define BOOST_PFR_BEGIN_MODULE_EXPORT export {
+#   define BOOST_PFR_END_MODULE_EXPORT }
+#else
 #   define BOOST_PFR_BEGIN_MODULE_EXPORT
-#endif
-
-#ifndef BOOST_PFR_END_MODULE_EXPORT
 #   define BOOST_PFR_END_MODULE_EXPORT
 #endif

+#if defined(BOOST_USE_MODULES) && !defined(BOOST_PFR_INTERFACE_UNIT)
+import boost.pfr;
+#endif
+
 #endif // BOOST_PFR_CONFIG_HPP
--- a/include/boost/pfr/core.hpp
+++ b/include/boost/pfr/core.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/core.hpp>

 #include <boost/pfr/detail/sequence_tuple.hpp>
@@ -17,10 +19,12 @@
 #include <boost/pfr/detail/make_integer_sequence.hpp>
 #include <boost/pfr/detail/tie_from_structure_tuple.hpp>

+#include <boost/pfr/tuple_size.hpp>
+
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
 #include <utility>      // metaprogramming stuff
-
-#include <boost/pfr/tuple_size.hpp>
+#endif

 /// \file boost/pfr/core.hpp
 /// Contains all the basic tuple-like interfaces \forcedlink{get}, \forcedlink{tuple_size}, \forcedlink{tuple_element_t}, and others.
@@ -48,24 +52,34 @@ BOOST_PFR_BEGIN_MODULE_EXPORT
 /// \endcode
 template <std::size_t I, class T>
 constexpr decltype(auto) get(const T& val) noexcept {
-    return detail::sequence_tuple::get<I>( detail::tie_as_tuple(val) );
+#if BOOST_PFR_USE_CPP26
+    const auto& [... members] = val;
+    return std::forward_like<const T &>(members...[I]);
+#else
+    return detail::sequence_tuple::get<I>(detail::tie_as_tuple(val));
+#endif
 }

 /// \overload get
 template <std::size_t I, class T>
 constexpr decltype(auto) get(T& val
-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
    , std::enable_if_t<std::is_assignable<T, T>::value>* = nullptr
 #endif
 ) noexcept {
+#if BOOST_PFR_USE_CPP26
+    auto& [... members] = val;
+    return std::forward_like<T &>(members...[I]);
+#else
    return detail::sequence_tuple::get<I>( detail::tie_as_tuple(val) );
+#endif
 }

-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
 /// \overload get
 template <std::size_t I, class T>
 constexpr auto get(T&, std::enable_if_t<!std::is_assignable<T, T>::value>* = nullptr) noexcept {
-    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::get on non const non assignable type is allowed only in C++17");
+    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::get on non const non assignable type is allowed only in C++17 and later");
    return 0;
 }
 #endif
@@ -74,7 +88,12 @@ constexpr auto get(T&, std::enable_if_t<!std::is_assignable<T, T>::value>* = nul
 /// \overload get
 template <std::size_t I, class T>
 constexpr auto get(T&& val, std::enable_if_t< std::is_rvalue_reference<T&&>::value>* = nullptr) noexcept {
+#if BOOST_PFR_USE_CPP26
+    auto&& [... members] = std::forward<T>(val);
+    return std::move(members...[I]);
+#else
    return std::move(detail::sequence_tuple::get<I>( detail::tie_as_tuple(val) ));
+#endif
 }


@@ -88,18 +107,18 @@ constexpr const U& get(const T& val) noexcept {
 /// \overload get
 template <class U, class T>
 constexpr U& get(T& val
-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
    , std::enable_if_t<std::is_assignable<T, T>::value>* = nullptr
 #endif
 ) noexcept {
    return detail::sequence_tuple::get_by_type_impl<U&>( detail::tie_as_tuple(val) );
 }

-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
 /// \overload get
 template <class U, class T>
 constexpr U& get(T&, std::enable_if_t<!std::is_assignable<T, T>::value>* = nullptr) noexcept {
-    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::get on non const non assignable type is allowed only in C++17");
+    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::get on non const non assignable type is allowed only in C++17 and later");
    return 0;
 }
 #endif
@@ -143,10 +162,15 @@ using tuple_element_t = typename tuple_element<I, T>::type;
 /// \endcode
 template <class T>
 constexpr auto structure_to_tuple(const T& val) {
+#if BOOST_PFR_USE_CPP26
+    const auto& [... members] = val;
+    return std::make_tuple(members...);
+#else
    return detail::make_stdtuple_from_tietuple(
        detail::tie_as_tuple(val),
        detail::make_index_sequence< tuple_size_v<T> >()
    );
+#endif
 }


@@ -168,31 +192,39 @@ constexpr auto structure_to_tuple(const T& val) {
 /// \endcode
 template <class T>
 constexpr auto structure_tie(const T& val) noexcept {
+#if BOOST_PFR_USE_CPP26
+    const auto& [... members] = val;
+    return std::tie(std::forward_like<const T &>(members)...);
+#else
    return detail::make_conststdtiedtuple_from_tietuple(
        detail::tie_as_tuple(const_cast<T&>(val)),
        detail::make_index_sequence< tuple_size_v<T> >()
    );
+#endif
 }


 /// \overload structure_tie
 template <class T>
 constexpr auto structure_tie(T& val
-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
    , std::enable_if_t<std::is_assignable<T, T>::value>* = nullptr
 #endif
 ) noexcept {
-    return detail::make_stdtiedtuple_from_tietuple(
-        detail::tie_as_tuple(val),
-        detail::make_index_sequence< tuple_size_v<T> >()
-    );
+#if BOOST_PFR_USE_CPP26
+    auto& [... members] = val;
+    return std::tie(std::forward_like<T &>(members)...);
+#else
+    return detail::make_stdtiedtuple_from_tietuple(detail::tie_as_tuple(val),
+                                                   detail::make_index_sequence<tuple_size_v<T> >());
+#endif
 }

-#if !BOOST_PFR_USE_CPP17
+#if !BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26
 /// \overload structure_tie
 template <class T>
 constexpr auto structure_tie(T&, std::enable_if_t<!std::is_assignable<T, T>::value>* = nullptr) noexcept {
-    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::structure_tie on non const non assignable type is allowed only in C++17");
+    static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::structure_tie on non const non assignable type is allowed only in C++17 and later modes");
    return 0;
 }
 #endif
@@ -249,4 +281,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_CORE_HPP
--- a/include/boost/pfr/core_name.hpp
+++ b/include/boost/pfr/core_name.hpp
@@ -14,16 +14,20 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/core_name.hpp>

 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/stdarray.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>

-#include <cstddef> // for std::size_t
-
 #include <boost/pfr/tuple_size.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <cstddef> // for std::size_t
+#endif
+
 /// \file boost/pfr/core_name.hpp
 /// Contains functions \forcedlink{get_name} and \forcedlink{names_as_array} to know which names each field of any \aggregate has.
 ///
@@ -79,8 +83,7 @@ auto
 names_as_array() noexcept {
    return detail::make_stdarray_from_tietuple(
        detail::tie_as_names_tuple<T>(),
-        detail::make_index_sequence< tuple_size_v<T> >(),
-        1L
+        detail::make_index_sequence< tuple_size_v<T> >()
    );
 }

@@ -110,4 +113,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_CORE_NAME_HPP
--- a/include/boost/pfr/detail/config.hpp
+++ b/include/boost/pfr/detail/config.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 // Copyright (c) 2022 Denis Mikhailov
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
--- a/include/boost/pfr/detail/core.hpp
+++ b/include/boost/pfr/detail/core.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -13,7 +13,9 @@
 // `boost::pfr::detail::for_each_field_dispatcher` functions.
 //
 // The whole PFR library is build on top of those two functions.
-#if BOOST_PFR_USE_CPP17
+#if BOOST_PFR_USE_CPP26
+#include <boost/pfr/detail/core26.hpp>
+#elif BOOST_PFR_USE_CPP17
 #   include <boost/pfr/detail/core17.hpp>
 #elif BOOST_PFR_USE_LOOPHOLE
 #   include <boost/pfr/detail/core14_loophole.hpp>
--- a/include/boost/pfr/detail/core14_classic.hpp
+++ b/include/boost/pfr/detail/core14_classic.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,13 +9,6 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <type_traits>
-#include <utility>      // metaprogramming stuff
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/offset_based_getter.hpp>
 #include <boost/pfr/detail/fields_count.hpp>
@@ -25,6 +18,11 @@ import std;
 #include <boost/pfr/detail/size_t_.hpp>
 #include <boost/pfr/detail/rvalue_t.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>
+#include <utility>      // metaprogramming stuff
+#endif
+
 #ifdef __clang__
 #   pragma clang diagnostic push
 #   pragma clang diagnostic ignored "-Wmissing-braces"
--- a/include/boost/pfr/detail/core14_loophole.hpp
+++ b/include/boost/pfr/detail/core14_loophole.hpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2017-2018 Alexandr Poltavsky, Antony Polukhin.
-// Copyright (c) 2019-2025 Antony Polukhin.
+// Copyright (c) 2019-2026 Antony Polukhin.
 //
 // 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)
@@ -24,13 +24,6 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <type_traits>
-#include <utility>
-#endif
-
 #include <boost/pfr/detail/offset_based_getter.hpp>
 #include <boost/pfr/detail/fields_count.hpp>
 #include <boost/pfr/detail/make_flat_tuple_of_references.hpp>
@@ -39,6 +32,9 @@ import std;
 #include <boost/pfr/detail/rvalue_t.hpp>
 #include <boost/pfr/detail/unsafe_declval.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <utility>
+#endif

 #ifdef __clang__
 #   pragma clang diagnostic push
--- a/include/boost/pfr/detail/core17.hpp
+++ b/include/boost/pfr/detail/core17.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/include/boost/pfr/detail/core17_generated.hpp
+++ b/include/boost/pfr/detail/core17_generated.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 // Copyright (c) 2023 Denis Mikhailov
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -22,9 +22,7 @@
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/size_t_.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits> // for std::conditional_t, std::is_reference
 #endif

--- a/include/boost/pfr/detail/core26.hpp
+++ b/include/boost/pfr/detail/core26.hpp
@@ -0,0 +1,39 @@
+// Copyright (c) 2016-2026 Antony Polukhin
+// Copyright (c) 2025 Jean-Michaël Celerier
+//
+// 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)
+
+// boost-no-inspect
+
+#ifndef BOOST_PFR_DETAIL_CORE26_HPP
+#define BOOST_PFR_DETAIL_CORE26_HPP
+#pragma once
+
+#include <boost/pfr/detail/sequence_tuple.hpp>
+
+namespace boost::pfr::detail {
+
+template<class T>
+constexpr auto tie_as_tuple(T &val) noexcept {
+    static_assert(!std::is_union<T>::value,
+                  "====================> Boost.PFR: For safety reasons it is forbidden to reflect "
+                  "unions. See `Reflection of unions` section in the docs for more info.");
+    auto &&[... members] = std::forward<T>(val);
+    return sequence_tuple::tuple<std::add_lvalue_reference_t<decltype(members)>...>{members...};
+}
+
+template <class T, class F, std::size_t... I>
+constexpr void for_each_field_dispatcher(T& t, F&& f, std::index_sequence<I...>) {
+    static_assert(
+        !std::is_union<T>::value,
+        "====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."
+    );
+    std::forward<F>(f)(
+        detail::tie_as_tuple(t)
+    );
+}
+
+} // namespace boost::pfr::detail
+
+#endif
--- a/include/boost/pfr/detail/core_name20_static.hpp
+++ b/include/boost/pfr/detail/core_name20_static.hpp
@@ -22,9 +22,7 @@
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/stdarray.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
 #include <string_view>
 #include <array>
@@ -218,8 +216,8 @@ constexpr std::string_view get_name() noexcept {
        "====================> Boost.PFR: It is impossible to extract name from old C array since it doesn't have named members"
    );
    static_assert(
-        sizeof(T) && BOOST_PFR_USE_CPP17,
-        "====================> Boost.PFR: Extraction of field's names is allowed only when the BOOST_PFR_USE_CPP17 macro enabled."
+        sizeof(T) && (BOOST_PFR_USE_CPP17 || BOOST_PFR_USE_CPP26),
+        "====================> Boost.PFR: Extraction of field's names is allowed only when the BOOST_PFR_USE_CPP17 or the BOOST_PFR_USE_CPP26 macro enabled."
   );

   return stored_name_of_field<T, I>.data();
--- a/include/boost/pfr/detail/detectors.hpp
+++ b/include/boost/pfr/detail/detectors.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,9 +9,7 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <functional>
 #include <type_traits>
 #endif
@@ -21,7 +19,7 @@ namespace boost { namespace pfr { namespace detail {
    struct can_not_apply{};

    template <template <class, class> class Detector, class Tleft, class Tright>
-    struct not_appliable {
+    struct not_applicable {
        static constexpr bool value = std::is_same<
            Detector<Tleft, Tright>,
            can_not_apply
--- a/include/boost/pfr/detail/fake_object.hpp
+++ b/include/boost/pfr/detail/fake_object.hpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2023 Bela Schaum, X-Ryl669, Denis Mikhailov.
-// Copyright (c) 2024-2025 Antony Polukhin
+// Copyright (c) 2024-2026 Antony Polukhin
 //
 // 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)
--- a/include/boost/pfr/detail/fields_count.hpp
+++ b/include/boost/pfr/detail/fields_count.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -12,11 +12,8 @@
 #include <boost/pfr/detail/size_t_.hpp>
 #include <boost/pfr/detail/unsafe_declval.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <climits>      // CHAR_BIT
-#include <cstdint>      // SIZE_MAX
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <limits>
 #include <type_traits>
 #include <utility>      // metaprogramming stuff
 #endif
@@ -210,6 +207,7 @@ using is_one_element_range = std::integral_constant<bool, Begin == Last>;
 using multi_element_range = std::false_type;
 using one_element_range = std::true_type;

+#if !BOOST_PFR_USE_CPP26
 ///////////////////// Fields count next expected compiler limitation
 constexpr std::size_t fields_count_compiler_limitation_next(std::size_t n) noexcept {
 #if defined(_MSC_VER) && (_MSC_VER <= 1920)
@@ -218,13 +216,13 @@ constexpr std::size_t fields_count_compiler_limitation_next(std::size_t n) noexc
 #else
    static_cast<void>(n);
 #endif
-    return SIZE_MAX;
+    return (std::numeric_limits<std::size_t>::max)();
 }

 ///////////////////// Fields count upper bound based on sizeof(T)
 template <class T>
 constexpr std::size_t fields_count_upper_bound_loose() noexcept {
-    return sizeof(T) * CHAR_BIT;
+    return sizeof(T) * std::numeric_limits<unsigned char>::digits + 1 /* +1 for "Arrays of Length Zero" extension */;
 }

 ///////////////////// Fields count binary search.
@@ -331,6 +329,7 @@ constexpr std::size_t fields_count_lower_bound_unbounded(int, size_t_<0>) noexce
    );
    return detail::fields_count_lower_bound_unbounded<T, last + 1>(1L, size_t_<result_maybe>{});
 }
+#endif

 ///////////////////// Choosing between array size, unbounded binary search, and linear search followed by unbounded binary search.
 template <class T>
@@ -345,6 +344,27 @@ constexpr auto fields_count_dispatch(long, long, std::true_type /*are_preconditi
    return sizeof(T) / sizeof(std::remove_all_extents_t<T>);
 }

+#if BOOST_PFR_USE_CPP26
+template<class T>
+constexpr auto fields_count_dispatch_impl(const T &t) noexcept
+{
+    const auto &[... elts] = t;
+    return std::integral_constant<std::size_t, sizeof...(elts)>{};
+}
+
+template<class T>
+constexpr auto fields_count_dispatch(long, int, std::true_type /*are_preconditions_met*/) noexcept
+    -> std::enable_if_t<std::is_scalar<T>::value, std::size_t>
+{
+    return 1;
+}
+
+template<class T>
+constexpr auto fields_count_dispatch(int, int, std::true_type /*are_preconditions_met*/) noexcept
+{
+    return decltype(detail::fields_count_dispatch_impl(std::declval<const T &>()))::value;
+}
+#else
 template <class T>
 constexpr auto fields_count_dispatch(long, int, std::true_type /*are_preconditions_met*/) noexcept
    -> decltype(sizeof(T{}))
@@ -363,6 +383,7 @@ constexpr std::size_t fields_count_dispatch(int, int, std::true_type /*are_preco
    constexpr std::size_t last = detail::fields_count_upper_bound<T, begin, begin + 1>(1L, 1L);
    return detail::fields_count_binary_search<T, begin, last>(detail::is_one_element_range<begin, last>{}, 1L);
 }
+#endif

 ///////////////////// Returns fields count
 template <class T>
@@ -428,9 +449,8 @@ constexpr std::size_t fields_count() noexcept {
    constexpr bool no_errors =
        type_is_complete && type_is_not_a_reference && type_fields_are_move_constructible
        && type_is_not_polymorphic && type_is_aggregate;
-
-    constexpr std::size_t result = detail::fields_count_dispatch<type>(1L, 1L, std::integral_constant<bool, no_errors>{});
-
+    constexpr std::size_t result
+        = detail::fields_count_dispatch<type>(1L, 1L, std::integral_constant<bool, no_errors>{});
    detail::assert_first_not_base<type, result>(1L);

 #ifndef __cpp_lib_is_aggregate
--- a/include/boost/pfr/detail/for_each_field.hpp
+++ b/include/boost/pfr/detail/for_each_field.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,21 +9,35 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <type_traits>      // metaprogramming stuff
-#endif
-
 #include <boost/pfr/detail/core.hpp>
 #include <boost/pfr/detail/fields_count.hpp>
 #include <boost/pfr/detail/for_each_field_impl.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>      // metaprogramming stuff
+#include <utility>          // forward_like
+#endif
+
 namespace boost { namespace pfr { namespace detail {

 template <class T, class F>
 constexpr void for_each_field(T&& value, F&& func) {
+#if BOOST_PFR_USE_CPP26
+    using no_ref = std::remove_reference_t<T>;
+    if constexpr (std::is_aggregate_v<no_ref> || std::is_bounded_array_v<no_ref>) {
+        auto &&[... members] = value;
+        ::boost::pfr::detail::for_each_field_impl(value,
+                                                  std::forward<F>(func),
+                                                  std::make_index_sequence<sizeof...(members)>{},
+                                                  std::is_rvalue_reference<T &&>{});
+    } else {
+        ::boost::pfr::detail::for_each_field_impl(value,
+                                                  std::forward<F>(func),
+                                                  std::make_index_sequence<1>{},
+                                                  std::is_rvalue_reference<T &&>{});
+    }
+#else
    constexpr std::size_t fields_count_val = boost::pfr::detail::fields_count<std::remove_reference_t<T>>();

    ::boost::pfr::detail::for_each_field_dispatcher(
@@ -42,6 +56,7 @@ constexpr void for_each_field(T&& value, F&& func) {
        },
        detail::make_index_sequence<fields_count_val>{}
    );
+#endif
 }

 }}} // namespace boost::pfr::detail
--- a/include/boost/pfr/detail/for_each_field_impl.hpp
+++ b/include/boost/pfr/detail/for_each_field_impl.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,15 +9,13 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <utility>      // metaprogramming stuff
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/rvalue_t.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <utility>      // metaprogramming stuff
+#endif
+
 namespace boost { namespace pfr { namespace detail {

 template <std::size_t Index>
@@ -33,7 +31,30 @@ constexpr void for_each_field_impl_apply(T&& v, F&& f, I /*i*/, int) {
    std::forward<F>(f)(std::forward<T>(v));
 }

-#if !defined(__cpp_fold_expressions) || __cpp_fold_expressions < 201603
+#if BOOST_PFR_USE_CPP26
+template<class T, class F, std::size_t... I>
+constexpr void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, auto move_values) {
+    if constexpr (std::is_aggregate_v<T> || std::is_bounded_array_v<T>) {
+        auto &&[... members] = t;
+        if constexpr (move_values)
+            (detail::for_each_field_impl_apply(std::move(members...[I]),
+                                               std::forward<F>(f),
+                                               size_t_<I>{},
+                                               1L),
+             ...);
+        else
+            (detail::for_each_field_impl_apply(
+                 members... [I], std::forward<F>(f), size_t_<I> {}, 1L),
+             ...);
+    } else {
+        if constexpr (move_values)
+            (detail::for_each_field_impl_apply(std::move(t), std::forward<F>(f), size_t_<I>{}, 1L),
+             ...);
+        else
+            (detail::for_each_field_impl_apply(t, std::forward<F>(f), size_t_<I>{}, 1L), ...);
+    }
+}
+#elif !defined(__cpp_fold_expressions) || __cpp_fold_expressions < 201603
 template <class T, class F, std::size_t... I>
 constexpr void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::false_type /*move_values*/) {
     const int v[] = {0, (
@@ -63,8 +84,6 @@ constexpr void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::
     (detail::for_each_field_impl_apply(sequence_tuple::get<I>(std::move(t)), std::forward<F>(f), size_t_<I>{}, 1L), ...);
 }
 #endif
-
 }}} // namespace boost::pfr::detail

-
 #endif // BOOST_PFR_DETAIL_FOR_EACH_FIELD_IMPL_HPP
--- a/include/boost/pfr/detail/functional.hpp
+++ b/include/boost/pfr/detail/functional.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,15 +9,13 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <functional>
-#include <cstdint>
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <cstdint>
+#include <functional>
+#endif
+
 namespace boost { namespace pfr { namespace detail {
    template <std::size_t I, std::size_t N>
    struct equal_impl {
--- a/include/boost/pfr/detail/io.hpp
+++ b/include/boost/pfr/detail/io.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -11,9 +11,7 @@

 #include <boost/pfr/detail/sequence_tuple.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <iosfwd>       // stream operators
 #include <iomanip>

--- a/include/boost/pfr/detail/make_flat_tuple_of_references.hpp
+++ b/include/boost/pfr/detail/make_flat_tuple_of_references.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,16 +9,13 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <utility>      // metaprogramming stuff
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/rvalue_t.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <utility>      // metaprogramming stuff
+#endif

 namespace boost { namespace pfr { namespace detail {

--- a/include/boost/pfr/detail/make_integer_sequence.hpp
+++ b/include/boost/pfr/detail/make_integer_sequence.hpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Sergei Fedorov
-// Copyright (c) 2019-2025 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // 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)
@@ -10,9 +10,7 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
 #include <utility>
 #include <cstddef>
--- a/include/boost/pfr/detail/offset_based_getter.hpp
+++ b/include/boost/pfr/detail/offset_based_getter.hpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2017-2018 Chris Beck
-// Copyright (c) 2019-2025 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // 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)
@@ -10,18 +10,15 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <type_traits>
-#include <utility>
-#include <memory>  // std::addressof
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/rvalue_t.hpp>
 #include <boost/pfr/detail/size_t_.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>
+#include <utility>
+#include <memory>  // std::addressof
+#endif

 namespace boost { namespace pfr { namespace detail {

--- a/include/boost/pfr/detail/possible_reflectable.hpp
+++ b/include/boost/pfr/detail/possible_reflectable.hpp
@@ -10,9 +10,7 @@
 #include <boost/pfr/detail/config.hpp>
 #include <boost/pfr/traits_fwd.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits> // for std::is_aggregate
 #endif

--- a/include/boost/pfr/detail/rvalue_t.hpp
+++ b/include/boost/pfr/detail/rvalue_t.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -7,9 +7,7 @@
 #define BOOST_PFR_DETAIL_RVALUE_T_HPP
 #pragma once

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
 #include <utility>      // std::enable_if_t
 #endif
--- a/include/boost/pfr/detail/sequence_tuple.hpp
+++ b/include/boost/pfr/detail/sequence_tuple.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -10,9 +10,7 @@
 #include <boost/pfr/detail/config.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <utility>      // metaprogramming stuff
 #include <cstddef>      // std::size_t
 #endif
--- a/include/boost/pfr/detail/size_array.hpp
+++ b/include/boost/pfr/detail/size_array.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,9 +9,7 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <cstddef>
 #endif

--- a/include/boost/pfr/detail/size_t_.hpp
+++ b/include/boost/pfr/detail/size_t_.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -7,6 +7,11 @@
 #define BOOST_PFR_DETAIL_SIZE_T_HPP
 #pragma once

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>
+#include <cstddef>
+#endif
+
 namespace boost { namespace pfr { namespace detail {

 ///////////////////// General utility stuff
--- a/include/boost/pfr/detail/stdarray.hpp
+++ b/include/boost/pfr/detail/stdarray.hpp
@@ -9,35 +9,31 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
-#include <utility> // metaprogramming stuff
-#include <array>
-#include <type_traits> // for std::common_type_t
-#include <cstddef>
-#endif
-
 #include <boost/pfr/detail/sequence_tuple.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <array>
+#if BOOST_PFR_CORE_NAME_ENABLED
+#   include <string_view>
+#endif
+#include <utility> // metaprogramming stuff
+#endif
+
 namespace boost { namespace pfr { namespace detail {

-template <class... Types>
-constexpr auto make_stdarray(const Types&... t) noexcept {
-    return std::array<std::common_type_t<Types...>, sizeof...(Types)>{t...};
-}
-
+#if BOOST_PFR_CORE_NAME_ENABLED
 template <class T, std::size_t... I>
-constexpr auto make_stdarray_from_tietuple(const T& t, std::index_sequence<I...>, int) noexcept {
-    return detail::make_stdarray(
+constexpr auto make_stdarray_from_tietuple(const T& t, std::index_sequence<I...>) noexcept {
+    return std::array<std::string_view, sizeof...(I)>{
        boost::pfr::detail::sequence_tuple::get<I>(t)...
-    );
+    };
 }
-
-template <class T>
-constexpr auto make_stdarray_from_tietuple(const T&, std::index_sequence<>, long) noexcept {
-    return std::array<std::nullptr_t, 0>{};
+#else
+template <class T, std::size_t... I>
+constexpr auto make_stdarray_from_tietuple(const T&, std::index_sequence<I...>) noexcept {
+    return nullptr;
 }
+#endif

 }}} // namespace boost::pfr::detail

--- a/include/boost/pfr/detail/stdtuple.hpp
+++ b/include/boost/pfr/detail/stdtuple.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,15 +9,13 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#include <boost/pfr/detail/sequence_tuple.hpp>
+
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <utility>      // metaprogramming stuff
 #include <tuple>
 #endif

-#include <boost/pfr/detail/sequence_tuple.hpp>
-
 namespace boost { namespace pfr { namespace detail {

 template <class T, std::size_t... I>
--- a/include/boost/pfr/detail/tie_from_structure_tuple.hpp
+++ b/include/boost/pfr/detail/tie_from_structure_tuple.hpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Adam Butcher, Antony Polukhin
-// Copyright (c) 2019-2025 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // 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)
@@ -16,9 +16,7 @@
 #include <boost/pfr/tuple_size.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <tuple>
 #endif

--- a/include/boost/pfr/detail/unsafe_declval.hpp
+++ b/include/boost/pfr/detail/unsafe_declval.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2025 Antony Polukhin.
+// Copyright (c) 2019-2026 Antony Polukhin.
 //
 // 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)
@@ -9,9 +9,7 @@

 #include <boost/pfr/detail/config.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
 #endif

@@ -29,9 +27,19 @@ template <class T>
 constexpr T unsafe_declval() noexcept {
    report_if_you_see_link_error_with_this_function();

+#ifdef BOOST_PFR_USE_LEGACY_UNSAFE_DECLVAL_IMPLEMENTATION
    typename std::remove_reference<T>::type* ptr = nullptr;
    ptr += 42; // suppresses 'null pointer dereference' warnings
    return static_cast<T>(*ptr);
+#else
+    // Looks like `static_cast<T>(*ptr)` to prvalue fails on clang in C++26.
+    // If this new implementation does not work for some cases, please, fill a
+    // bug report and feel free to
+    // define BOOST_PFR_USE_LEGACY_UNSAFE_DECLVAL_IMPLEMENTATION.
+    using func_ptr_t = T(*)();
+    func_ptr_t ptr = nullptr;
+    return ptr();
+#endif
 }

 }}} // namespace boost::pfr::detail
--- a/include/boost/pfr/functions_for.hpp
+++ b/include/boost/pfr/functions_for.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,8 +9,10 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
 #include <boost/pfr/ops_fields.hpp>
 #include <boost/pfr/io_fields.hpp>
+#endif

 /// \file boost/pfr/functions_for.hpp
 /// Contains BOOST_PFR_FUNCTIONS_FOR macro that defined comparison and stream operators for T along with hash_value function.
--- a/include/boost/pfr/functors.hpp
+++ b/include/boost/pfr/functors.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/ops.hpp>

 #include <boost/pfr/detail/functional.hpp>
@@ -222,4 +224,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_FUNCTORS_HPP
--- a/include/boost/pfr/io.hpp
+++ b/include/boost/pfr/io.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/detectors.hpp>
 #include <boost/pfr/io_fields.hpp>

@@ -38,25 +40,25 @@ namespace detail {
 ///////////////////// Helper typedefs
    template <class Stream, class Type>
    using enable_not_ostreamable_t = std::enable_if_t<
-        not_appliable<ostreamable_detector, Stream&, const std::remove_reference_t<Type>&>::value,
+        not_applicable<ostreamable_detector, Stream&, const std::remove_reference_t<Type>&>::value,
        Stream&
    >;

    template <class Stream, class Type>
    using enable_not_istreamable_t = std::enable_if_t<
-        not_appliable<istreamable_detector, Stream&, Type&>::value,
+        not_applicable<istreamable_detector, Stream&, Type&>::value,
        Stream&
    >;

    template <class Stream, class Type>
    using enable_ostreamable_t = std::enable_if_t<
-        !not_appliable<ostreamable_detector, Stream&, const std::remove_reference_t<Type>&>::value,
+        !not_applicable<ostreamable_detector, Stream&, const std::remove_reference_t<Type>&>::value,
        Stream&
    >;

    template <class Stream, class Type>
    using enable_istreamable_t = std::enable_if_t<
-        !not_appliable<istreamable_detector, Stream&, Type&>::value,
+        !not_applicable<istreamable_detector, Stream&, Type&>::value,
        Stream&
    >;

@@ -118,4 +120,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_IO_HPP
--- a/include/boost/pfr/io_fields.hpp
+++ b/include/boost/pfr/io_fields.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -10,16 +10,19 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/core.hpp>
-
-#include <type_traits>
-#include <utility>      // metaprogramming stuff
-
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/io.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>
 #include <boost/pfr/tuple_size.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>
+#include <utility>      // metaprogramming stuff
+#endif
+
 /// \file boost/pfr/io_fields.hpp
 /// Contains IO manipulator \forcedlink{io_fields} to read/write any \aggregate field-by-field.
 ///
@@ -52,6 +55,7 @@ struct io_fields_impl {
    T value;
 };

+BOOST_PFR_BEGIN_MODULE_EXPORT

 template <class Char, class Traits, class T>
 std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& out, io_fields_impl<const T&>&& x) {
@@ -118,8 +122,6 @@ std::basic_istream<Char, Traits>& operator>>(std::basic_istream<Char, Traits>& i
    return in;
 }

-BOOST_PFR_BEGIN_MODULE_EXPORT
-
 template <class Char, class Traits, class T>
 std::basic_istream<Char, Traits>& operator>>(std::basic_istream<Char, Traits>& in, io_fields_impl<const T&>&& ) {
    static_assert(sizeof(T) && false, "====================> Boost.PFR: Attempt to use istream operator on a boost::pfr::io_fields wrapped type T with const qualifier.");
@@ -169,4 +171,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_IO_FIELDS_HPP
--- a/include/boost/pfr/ops.hpp
+++ b/include/boost/pfr/ops.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/detectors.hpp>
 #include <boost/pfr/ops_fields.hpp>

@@ -40,13 +42,13 @@ namespace detail {
 ///////////////////// Helper typedefs that are used by all the ops
    template <template <class, class> class Detector, class T, class U>
    using enable_not_comp_base_t = std::enable_if_t<
-        not_appliable<Detector, T const&, U const&>::value,
+        not_applicable<Detector, T const&, U const&>::value,
        bool
    >;

    template <template <class, class> class Detector, class T, class U>
    using enable_comp_base_t = std::enable_if_t<
-        !not_appliable<Detector, T const&, U const&>::value,
+        !not_applicable<Detector, T const&, U const&>::value,
        bool
    >;
 ///////////////////// std::enable_if_t like functions that enable only if types do not support operation
@@ -59,7 +61,7 @@ namespace detail {
    template <class T, class U> using enable_not_ge_comp_t = enable_not_comp_base_t<comp_ge_detector, T, U>;

    template <class T> using enable_not_hashable_t = std::enable_if_t<
-        not_appliable<hash_detector, const T&, const T&>::value,
+        not_applicable<hash_detector, const T&, const T&>::value,
        std::size_t
    >;
 ///////////////////// std::enable_if_t like functions that enable only if types do support operation
@@ -72,7 +74,7 @@ namespace detail {
    template <class T, class U> using enable_ge_comp_t = enable_comp_base_t<comp_ge_detector, T, U>;

    template <class T> using enable_hashable_t = std::enable_if_t<
-        !not_appliable<hash_detector, const T&, const T&>::value,
+        !not_applicable<hash_detector, const T&, const T&>::value,
        std::size_t
    >;
 } // namespace detail
@@ -187,4 +189,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_OPS_HPP
--- a/include/boost/pfr/ops_fields.hpp
+++ b/include/boost/pfr/ops_fields.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/core.hpp>
 #include <boost/pfr/detail/functional.hpp>

@@ -129,4 +131,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_OPS_HPP
--- a/include/boost/pfr/traits.hpp
+++ b/include/boost/pfr/traits.hpp
@@ -9,8 +9,13 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #include <boost/pfr/detail/possible_reflectable.hpp>
+
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits>
+#endif

 /// \file boost/pfr/traits.hpp
 /// Contains traits \forcedlink{is_reflectable} and \forcedlink{is_implicitly_reflectable} for detecting an ability to reflect type.
@@ -60,5 +65,7 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_TRAITS_HPP

--- a/include/boost/pfr/traits_fwd.hpp
+++ b/include/boost/pfr/traits_fwd.hpp
@@ -9,6 +9,8 @@

 #include <boost/pfr/detail/config.hpp>

+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 namespace boost { namespace pfr {

 BOOST_PFR_BEGIN_MODULE_EXPORT
@@ -20,6 +22,7 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_DETAIL_TRAITS_FWD_HPP

-
--- a/include/boost/pfr/tuple_size.hpp
+++ b/include/boost/pfr/tuple_size.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -10,12 +10,16 @@

 #include <boost/pfr/detail/config.hpp>

-#include <type_traits>
-#include <utility>      // metaprogramming stuff
+#if !defined(BOOST_USE_MODULES) || defined(BOOST_PFR_INTERFACE_UNIT)

 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/fields_count.hpp>

+#if !defined(BOOST_PFR_INTERFACE_UNIT)
+#include <type_traits>
+#include <utility>      // metaprogramming stuff
+#endif
+
 /// \file boost/pfr/tuple_size.hpp
 /// Contains tuple-like interfaces to get fields count \forcedlink{tuple_size}, \forcedlink{tuple_size_v}.
 ///
@@ -49,4 +53,6 @@ BOOST_PFR_END_MODULE_EXPORT

 }} // namespace boost::pfr

+#endif  // #if defined(BOOST_USE_MODULES) && !defined(BOOST_PFR_INTERFACE_UNIT)
+
 #endif // BOOST_PFR_TUPLE_SIZE_HPP
--- a/index.html
+++ b/index.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <!--
- Copyright (c) 2014-2025 Antony Polukhin
+ Copyright (c) 2014-2026 Antony Polukhin
 antoshkka at gmail dot com

 Distributed under the Boost Software License,
--- a/misc/generate_cpp17.py
+++ b/misc/generate_cpp17.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python

-# Copyright (c) 2016-2025 Antony Polukhin
+# Copyright (c) 2016-2026 Antony Polukhin
 # Copyright (c) 2023 Denis Mikhailov
 #
 # Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -15,7 +15,7 @@ import string
 ascii_letters = string.ascii_letters.replace("o", "").replace("O", "").replace("i", "").replace("I", "").replace("T", "")
 WORKAROUND_CAST_EXPRESSIONS_LIMIT_PER_LINE = 3

-PROLOGUE = """// Copyright (c) 2016-2025 Antony Polukhin
+PROLOGUE = """// Copyright (c) 2016-2026 Antony Polukhin
 // Copyright (c) 2023 Denis Mikhailov
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -39,9 +39,7 @@ PROLOGUE = """// Copyright (c) 2016-2025 Antony Polukhin
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/size_t_.hpp>

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#else
+#if !defined(BOOST_PFR_INTERFACE_UNIT)
 #include <type_traits> // for std::conditional_t, std::is_reference
 #endif

--- a/misc/strip_boost_namespace.sh
+++ b/misc/strip_boost_namespace.sh
@@ -1,10 +1,12 @@
 #!/bin/bash

-# Copyright (c) 2021 Antony Polukhin
+# Copyright (c) 2021-2026 Antony Polukhin
 #
 # 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)

+PFR_TEST_COMPILER=clang++-19
+
 echo "***** Making target path"
 TARGET_PATH="`dirname \"$0\"`/../../pfr_non_boost"
 rm -rf ${TARGET_PATH}/*
@@ -24,61 +26,83 @@ rm ${TARGET_PATH}/misc/strip_boost_namespace.sh
 rm -rf ${TARGET_PATH}/meta

 echo "***** Changing sources"
-find ${TARGET_PATH} -type f | xargs sed -i 's|namespace boost { ||g'
-find ${TARGET_PATH} -type f | xargs sed -i 's|namespace boost {||g'
-find ${TARGET_PATH} -type f | xargs sed -i 's|} // namespace boost::| // namespace |g'
+find ${TARGET_PATH} -type f | xargs sed -i \
+        -e 's|namespace boost { ||g' \
+        -e 's|namespace boost {||g' \
+        -e 's|} // namespace boost::| // namespace |g' \
+        \
+        -e 's/::boost::pfr/::pfr/g' \
+        -e 's/boost::pfr/pfr/g' \
+        -e 's/BOOST_PFR_/PFR_/g' \
+        -e 's|boost/pfr|pfr|g' \
+        \
+        -e 's/boost_pfr /pfr /g' \
+        -e 's/boost_pfr_/pfr_/g' \
+        -e 's/boost_pfr)/pfr)/g' \
+        -e 's/Boost::pfr/pfr::pfr/g' \
+        -e 's/BOOST_USE_MODULES/PFR_USE_MODULES/g' \
+        -e 's|boost\.pfr;|pfr;|g' \

-find ${TARGET_PATH} -type f | xargs sed -i 's/::boost::pfr/::pfr/g'
-find ${TARGET_PATH} -type f | xargs sed -i 's/boost::pfr/pfr/g'
-find ${TARGET_PATH} -type f | xargs sed -i 's/BOOST_PFR_/PFR_/g'
-find ${TARGET_PATH} -type f | xargs sed -i 's|boost/pfr|pfr|g'
-
-find ${TARGET_PATH}/doc -type f | xargs sed -i 's|boost.pfr.|pfr.|g'
-find ${TARGET_PATH}/doc -type f | xargs sed -i 's|Boost.PFR|PFR|g'
+find ${TARGET_PATH}/doc -type f | xargs sed -i \
+        -e 's|boost\.pfr\.|pfr.|g' \
+        -e 's|boost\.pfr`|pfr`|g' \
+        -e 's/boost_pfr\./pfr./g' \
+        -e 's|Boost\.PFR|PFR|g' \

 sed -i  's|# \[Boost.PFR\](https://boost.org/libs/pfr)|# [PFR](https://apolukhin.github.io/pfr_non_boost/)|g' ${TARGET_PATH}/README.md

 echo -n "***** Testing: "
-if g++-12 -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
    echo -n "OK"
 else
    echo -n "FAIL"
    exit 2
 fi
-if g++-12 -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
-    echo -n "OK"
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
+    echo -n ", OK"
 else
-    echo -n "FAIL"
+    echo -n ", FAIL"
    exit 3
 fi

-if g++-12 -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=1 -DBOOST_PFR_USE_CPP17=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/get_name.cpp && ./a.out > /dev/null; then
-    echo -e ", OK"
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_ENABLE_GET_NAME_STATIC=1 -DBOOST_PFR_USE_CPP17=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/get_name.cpp && ./a.out > /dev/null; then
+    echo -n ", OK"
 else
-    echo -e ", FAIL"
+    echo -n ", FAIL"
    exit 4
 fi

-if g++-12 -std=c++2a -DPFR_USE_LOOPHOLE=0 -DPFR_USE_CPP17=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
-    echo -n "OK"
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_USE_LOOPHOLE=0 -DPFR_USE_CPP17=1 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
+    echo -n ", OK"
 else
-    echo -n "FAIL"
+    echo -n ", FAIL"
    exit 5
 fi
-if g++-12 -std=c++2a -DPFR_USE_LOOPHOLE=1 -DPFR_USE_CPP17=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_USE_LOOPHOLE=1 -DPFR_USE_CPP17=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/motivating_example0.cpp && ./a.out > /dev/null; then
    echo -n ", OK"
 else
    echo -n ", FAIL"
    exit 6
 fi

-if g++-12 -std=c++2a -DPFR_USE_LOOPHOLE=0 -DPFR_USE_CPP17=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/get.cpp && ./a.out > /dev/null; then
-    echo -e ", OK"
+if ${PFR_TEST_COMPILER} -std=c++2a -DPFR_USE_LOOPHOLE=0 -DPFR_USE_CPP17=0 -I ${TARGET_PATH}/include/ ${TARGET_PATH}/example/get.cpp && ./a.out > /dev/null; then
+    echo -n ", OK"
 else
-    echo -e ", FAIL"
+    echo -n ", FAIL"
    exit 7
 fi

+mkdir build_module || :
+cd build_module
+if cmake -DPFR_USE_MODULES=1 -DBUILD_TESTING=1 -GNinja -DCMAKE_CXX_COMPILER=${PFR_TEST_COMPILER} ${TARGET_PATH} && cmake --build .; then
+    echo "Modules check OK"
+else
+    echo "Modules check FAIL"
+    exit 8
+fi
+cd ..
+
+rm -rf build_module || :
 rm a.out || :

-echo "***** Done"
+echo -e "\n***** Done"
--- a/module/CMakeLists.txt
+++ b/module/CMakeLists.txt
@@ -1,37 +0,0 @@
-# Copyright (c) 2016-2025 Antony Polukhin
-#
-# Distributed under the Boost Software License, Version 1.0.
-# https://www.boost.org/LICENSE_1_0.txt
-
-cmake_minimum_required(VERSION 3.28)
-
-function (_add_boost_pfr_module_impl NAME)
-    add_library(${NAME})
-    target_compile_features(${NAME} PUBLIC cxx_std_20)
-    target_sources(${NAME} PUBLIC
-        FILE_SET modules_public TYPE CXX_MODULES FILES
-            ${CMAKE_CURRENT_LIST_DIR}/pfr.cppm
-    )
-endfunction()
-
-function (add_boost_pfr_module NAME)
-    _add_boost_pfr_module_impl(${NAME})
-    target_include_directories(${NAME} PRIVATE ${CMAKE_CURRENT_LIST_DIR}/../include)
-
-    _add_boost_pfr_module_impl(${NAME}_migration)
-    target_include_directories(${NAME}_migration PUBLIC ${CMAKE_CURRENT_LIST_DIR}/../include)
-    target_compile_definitions(${NAME}_migration PRIVATE BOOST_PFR_ATTACH_TO_GLOBAL_MODULE)
-endfunction()
-
-add_boost_pfr_module(boost_pfr_module)
-add_library(Boost::pfr_module ALIAS boost_pfr_module)
-add_library(Boost::pfr_module_migration ALIAS boost_pfr_module_migration)
-
-if (BUILD_TESTING)
-    add_executable(boost_pfr_module_usage usage_sample.cpp)
-    target_link_libraries(boost_pfr_module_usage PRIVATE Boost::pfr_module)
-
-    # Make sure that mixing includes and imports is fine for different TU
-    add_executable(boost_pfr_module_usage_mu usage_test_mu1.cpp usage_test_mu2.cpp)
-    target_link_libraries(boost_pfr_module_usage_mu PRIVATE Boost::pfr_module_migration)
-endif()
--- a/modules/boost_pfr.cppm
+++ b/modules/boost_pfr.cppm
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -6,16 +6,21 @@
 // To compile manually use a command like the folowing:
 // clang++ -I ../include -std=c++20 --precompile -x c++-module pfr.cppm

-#define BOOST_PFR_BEGIN_MODULE_EXPORT export {
-#define BOOST_PFR_END_MODULE_EXPORT }
-
-#ifndef BOOST_PFR_HAS_STD_MODULE
 module;
+
+#include <version>
+#include <cstddef>
+#include <cstdint>
+
+#ifdef BOOST_PFR_USE_STD_MODULE
+import std;
+#else
 #include <array>
 #include <cstddef>
 #include <functional>
 #include <iomanip>
 #include <iostream>
+#include <limits>
 #include <memory>
 #include <string>
 #include <string_view>
@@ -25,20 +30,13 @@ module;
 #include <variant>
 #endif

-export module Boost.PFR;
+#define BOOST_PFR_INTERFACE_UNIT

-#ifdef BOOST_PFR_HAS_STD_MODULE
-import std;
-#endif
+export module boost.pfr;

 #ifdef __clang__
 #   pragma clang diagnostic ignored "-Winclude-angled-in-module-purview"
 #endif

-#ifdef BOOST_PFR_ATTACH_TO_GLOBAL_MODULE
-extern "C++" {
 #include <boost/pfr.hpp>
-}
-#else
-#include <boost/pfr.hpp>
-#endif
+
--- a/modules/usage_sample.cpp
+++ b/modules/usage_sample.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -11,7 +11,7 @@
 #include <iomanip>
 #include <string>

-import Boost.PFR;
+import boost.pfr;

 struct some_person {
    std::string name;
--- a/modules/usage_test_mu1.cpp
+++ b/modules/usage_test_mu1.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/modules/usage_test_mu2.cpp
+++ b/modules/usage_test_mu2.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -9,7 +9,7 @@
 #include <iostream>
 #include <iomanip>

-import Boost.PFR;
+import boost.pfr;

 struct some_person {
    std::string name;
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -0,0 +1,32 @@
+# Copyright  (c) 2016-2026 Antony Polukhin
+# 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
+
+if(NOT TARGET tests)
+  add_custom_target(tests)
+endif()
+
+file(GLOB CORE_RUN_FILES "core/run/*.cpp")
+foreach (testsourcefile ${CORE_RUN_FILES})
+    get_filename_component(testname ${testsourcefile} NAME_WE)
+    add_executable(pfr_core_${testname} ${testsourcefile})
+    target_link_libraries(pfr_core_${testname} Boost::pfr Boost::core Boost::container_hash)
+    target_include_directories(pfr_core_${testname} PRIVATE ../../../)
+    add_test(NAME pfr_core_${testname} COMMAND pfr_core_${testname})
+    add_dependencies(tests pfr_core_${testname})
+endforeach()
+
+if(CMAKE_VERSION VERSION_LESS 3.12)
+    message(AUTHOR_WARNING "Disabling core_name tests as CMake version 3.12+ is required but using ${CMAKE_VERSION}")
+else()
+    file(GLOB CORE_NAME_RUN_FILES "core_name/run/*.cpp")
+    foreach (testsourcefile ${CORE_NAME_RUN_FILES})
+        get_filename_component(testname ${testsourcefile} NAME_WE)
+        add_executable(pfr_corename_${testname} ${testsourcefile})
+        target_compile_features(pfr_corename_${testname} PUBLIC cxx_std_20)
+        target_link_libraries(pfr_corename_${testname} Boost::pfr Boost::core Boost::container_hash)
+        target_include_directories(pfr_corename_${testname} PRIVATE ../../../)
+        add_test(NAME pfr_corename_${testname} COMMAND pfr_corename_${testname})
+        add_dependencies(tests pfr_corename_${testname})
+    endforeach()
+endif()
--- a/test/appveyor.yml
+++ b/test/appveyor.yml
@@ -41,16 +41,16 @@ environment:
 #      ADDRMD: 32,64
 #      CXXSTD: 17,latest
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correclty use std::tuple_size
+      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correctly use std::tuple_size
      ADDRMD: 32,64
      CXXSTD: 17,latest
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correclty use std::tuple_size
+      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correctly use std::tuple_size
      ADDRMD: 32,64
      CXXSTD: 17,latest
      CXXFLAGS: /permissive-
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correclty use std::tuple_size
+      TOOLSET: msvc # clang-win has problems with structured bindings - it can not correctly use std::tuple_size
      ADDRMD: 32,64
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
      ADDPATH: C:\cygwin\bin;
--- a/test/cmake_subdir_test/CMakeLists.txt
+++ b/test/cmake_subdir_test/CMakeLists.txt
@@ -0,0 +1,21 @@
+# Copyright  (c) 2016-2026 Antony Polukhin
+# 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
+
+cmake_minimum_required(VERSION 3.5...4.0)
+
+project(pfr_subdir_test LANGUAGES CXX)
+
+add_subdirectory(../../../assert boostorg/assert)
+add_subdirectory(../../../container_hash boostorg/container_hash)
+add_subdirectory(../../../core boostorg/core)
+add_subdirectory(../../../config boostorg/config)
+add_subdirectory(../../../detail boostorg/detail)
+add_subdirectory(../../../describe boostorg/describe)
+add_subdirectory(../../../integer boostorg/integer)
+add_subdirectory(../../../mp11 boostorg/mp11)
+add_subdirectory(../../../static_assert boostorg/static_assert)
+add_subdirectory(../../../throw_exception boostorg/throw_exception)
+add_subdirectory(../../../type_traits boostorg/type_traits)
+
+add_subdirectory(../../ boostorg/pfr)
--- a/test/config/print_config.cpp
+++ b/test/config/print_config.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -14,6 +14,7 @@
 int main() {
    std::cout << "Platform info:" << '\n'
        << "BOOST_PFR_USE_CPP17 == " << BOOST_PFR_USE_CPP17 << '\n'
+        << "BOOST_PFR_USE_CPP26 == " << BOOST_PFR_USE_CPP26 << '\n'
        << "BOOST_PFR_USE_LOOPHOLE == " << BOOST_PFR_USE_LOOPHOLE << '\n'
        << "BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE == " << BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE << '\n'
        << "BOOST_PFR_HAS_GUARANTEED_COPY_ELISION == " << BOOST_PFR_HAS_GUARANTEED_COPY_ELISION << '\n'
--- a/test/core/Jamfile.v2
+++ b/test/core/Jamfile.v2
@@ -1,4 +1,4 @@
-#  Copyright (C) 2016-2025 Antony Polukhin.
+#  Copyright (C) 2016-2026 Antony Polukhin.
 #
 # Use, modification and distribution is subject to the Boost Software License,
 # Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
@@ -23,7 +23,7 @@ project
        [ requires cxx14_constexpr ]
    ;

-########## BEGIN of helpers to detect Loophole trick support
+########## BEGIN of helpers to detect Loophole and variadic structured binding support

 actions mp_simple_run_action
 {
@@ -42,6 +42,9 @@ rule mp-run-simple ( sources + : args * : input-files * : requirements * : targe
 mp-run-simple loophole_detection.cpp : : : : compiler_supports_loophole ;
 explicit compiler_supports_loophole ;

+mp-run-simple variadic_structured_binding_detection.cpp : : : : compiler_supports_vsb ;
+explicit compiler_supports_vsb ;
+
 ########## END of helpers to detect Loophole trick support


@@ -49,10 +52,14 @@ local DISABLE_ON_MSVC = ; #<toolset>msvc:<build>no ;
 local REQUIRE_LOOPHOLE =
    [ check-target-builds ../core//compiler_supports_loophole : : <build>no ]
  ;
+local REQUIRE_VSB =
+    [ check-target-builds ../core//compiler_supports_vsb : : <build>no ]
+  ;

-local STRUCTURED_BINDING_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=1 [ requires cxx17_structured_bindings ] ;
-local LOOPHOLE_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=1 <define>BOOST_PFR_USE_CPP17=0 $(REQUIRE_LOOPHOLE) ;
-local CLASSIC_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=0 $(DISABLE_ON_MSVC) ;
+local VARIADIC_STRUCTURED_BINDING_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=0 <define>BOOST_PFR_USE_CPP26=1 $(REQUIRE_VSB) ;
+local STRUCTURED_BINDING_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=1 <define>BOOST_PFR_USE_CPP26=0 [ requires cxx17_structured_bindings ] ;
+local LOOPHOLE_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=1 <define>BOOST_PFR_USE_CPP17=0 <define>BOOST_PFR_USE_CPP26=0 $(REQUIRE_LOOPHOLE) ;
+local CLASSIC_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=0 <define>BOOST_PFR_USE_CPP26=0 $(DISABLE_ON_MSVC) ;

 test-suite pfr_tests
  :
@@ -109,6 +116,7 @@ local BLACKLIST_TESTS_FOR_CLASSIC =
 for local source_file in [ glob ./run/*.cpp ] [ glob ../../example/*.cpp ]
 {
    local target_name = $(source_file[1]:B) ;
+    pfr_tests += [ run $(source_file) : : : $(VARIADIC_STRUCTURED_BINDING_ENGINE) : $(target_name)_vsb ] ;
    pfr_tests += [ run $(source_file) : : : $(STRUCTURED_BINDING_ENGINE) : $(target_name)_sb ] ;

    if ! $(target_name) in $(BLACKLIST_TESTS_FOR_LOOPHOLE)
--- a/test/core/compile-fail/constructible_0_or_more_args.cpp
+++ b/test/core/compile-fail/constructible_0_or_more_args.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2023-2025 Antony Polukhin
+// Copyright (c) 2023-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/constructible_1_or_more_args.cpp
+++ b/test/core/compile-fail/constructible_1_or_more_args.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2023-2025 Antony Polukhin
+// Copyright (c) 2023-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/fields_count_on_reference.cpp
+++ b/test/core/compile-fail/fields_count_on_reference.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/inherited.cpp
+++ b/test/core/compile-fail/inherited.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2021 Denis Mikhailov
-// Copyright (c) 2021 Antony Polukhin
+// Copyright (c) 2021-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/inherited_nonempty.cpp
+++ b/test/core/compile-fail/inherited_nonempty.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Antony Polukhin
+// Copyright (c) 2021-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/movable_and_lvalue_references.cpp
+++ b/test/core/compile-fail/movable_and_lvalue_references.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/non_aggregate.cpp
+++ b/test/core/compile-fail/non_aggregate.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/ops_on_union.cpp
+++ b/test/core/compile-fail/ops_on_union.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/ops_unions.cpp
+++ b/test/core/compile-fail/ops_unions.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/ops_unrestricted_unions.cpp
+++ b/test/core/compile-fail/ops_unrestricted_unions.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/pfr_review_test2.cpp
+++ b/test/core/compile-fail/pfr_review_test2.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 // Copyright (c) 2020 Richard Hodges
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
--- a/test/core/compile-fail/private_fields.cpp
+++ b/test/core/compile-fail/private_fields.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/protected_fields.cpp
+++ b/test/core/compile-fail/protected_fields.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/rvalue_tie.cpp
+++ b/test/core/compile-fail/rvalue_tie.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/compile-fail/virtual_functions.cpp
+++ b/test/core/compile-fail/virtual_functions.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/fields_count_immutable.cpp
+++ b/test/core/fields_count_immutable.cpp
@@ -0,0 +1,37 @@
+// Copyright (c) 2025-2026 Antony Polukhin
+//
+// 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)
+
+// Test from https://github.com/boostorg/pfr/issues/126
+
+#include <boost/pfr.hpp>
+
+struct NoCopy {
+    NoCopy() = default;
+    NoCopy(NoCopy const&) = delete;
+    NoCopy(NoCopy&&) = delete;
+    NoCopy& operator=(NoCopy&&) = delete;
+    NoCopy& operator=(NoCopy const&) = delete;
+};
+
+struct Group {
+    NoCopy m;
+    NoCopy m2;
+    NoCopy m3;
+    NoCopy m4;
+};
+
+Group ReturnGroup() { return {};}
+
+int main()
+{   
+#ifdef __cpp_lib_is_aggregate
+    static_assert(std::is_aggregate_v<Group>, "Group is totally an aggregate");
+#endif
+    static_assert(BOOST_PFR_HAS_GUARANTEED_COPY_ELISION, "Compiler implements mandatory copy elision");
+    Group aggregate_init_test{{}, {}, {}, {}};
+    Group elision_test = ReturnGroup();
+    return  boost::pfr::tuple_size_v<Group>;
+}
+
--- a/test/core/fields_count_on_incomplete_type.cpp
+++ b/test/core/fields_count_on_incomplete_type.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2023-2025 Antony Polukhin
+// Copyright (c) 2023-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/loophole_detection.cpp
+++ b/test/core/loophole_detection.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/offset_based_getter.cpp
+++ b/test/core/offset_based_getter.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2019 Ilya Kiselev
-// Copyright (c) 2019-2025 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/bitfields_count.cpp
+++ b/test/core/run/bitfields_count.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/constexpr_ops.cpp
+++ b/test/core/run/constexpr_ops.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -13,7 +13,6 @@
 #include <set>
 #include <string>

-#include <boost/config.hpp>
 #include <boost/core/lightweight_test.hpp>

 #ifdef __clang__
--- a/test/core/run/core17_generated.cpp
+++ b/test/core/run/core17_generated.cpp
@@ -24,7 +24,7 @@ struct A {
 };

 int main() {
-#if BOOST_PFR_USE_CPP17
+#if BOOST_PFR_USE_CPP17 && !BOOST_PFR_USE_CPP26 && !defined(BOOST_USE_MODULES)  // TODO: fix for BOOST_USE_MODULES
    const volatile int cv_value = 0;
    volatile int v_value = 0;
    const int c_value = 0;
--- a/test/core/run/destructuring_tie.cpp
+++ b/test/core/run/destructuring_tie.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Adam Butcher, Antony Polukhin
-// Copyright (c) 2019-2025 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/error_pfr_c1202.cpp
+++ b/test/core/run/error_pfr_c1202.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
@@ -13,6 +13,11 @@
 #include <iostream>
 #include <type_traits>

+#if defined(BOOST_USE_MODULES) // TODO: fix for BOOST_USE_MODULES
+int main() {}
+
+#else
+
 template <typename T>
 class CfgAttrib {
 public:
@@ -99,3 +104,5 @@ int main() {
    boost::pfr::get<0>(aCfg); // also C1202
 #endif
 }
+
+#endif
--- a/test/core/run/fields_count_on_const.cpp
+++ b/test/core/run/fields_count_on_const.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/for_each_field.cpp
+++ b/test/core/run/for_each_field.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/functions_for.cpp
+++ b/test/core/run/functions_for.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
@@ -14,7 +14,7 @@
 #include <set>
 #include <string>

-#include <boost/functional/hash.hpp>
+#include <boost/container_hash/hash.hpp>
 #include <unordered_set>

 struct adl_hash {
--- a/test/core/run/get_by_type.cpp
+++ b/test/core/run/get_by_type.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/get_const_field.cpp
+++ b/test/core/run/get_const_field.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 //
 // 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)
@@ -6,8 +6,6 @@

 #include <boost/pfr/core.hpp>

-#include <boost/type_index.hpp>
-
 #include <boost/core/lightweight_test.hpp>

 namespace testing {
@@ -27,18 +25,16 @@ void test_get_in_anon_ns_const_field() {
    anon x{{1}, {2}};

    BOOST_TEST_EQ(boost::pfr::get<0>(x).data, 1);
-    auto x0_type = boost::typeindex::type_id_with_cvr<decltype(
-        boost::pfr::get<0>(x)
-    )>();
-    // Use runtime check to make sure that Loophole fails to compile structure_tie
-    BOOST_TEST_EQ(x0_type, boost::typeindex::type_id_with_cvr<other_anon&>());
+    static_assert(std::is_same<
+        decltype(boost::pfr::get<0>(x)),
+        other_anon&
+    >::value, "");

    BOOST_TEST_EQ(boost::pfr::get<1>(x).data, 2);
-    auto x1_type = boost::typeindex::type_id_with_cvr<decltype(
-        boost::pfr::get<1>(x)
-    )>();
-    // Use runtime check to make sure that Loophole fails to compile structure_tie
-    BOOST_TEST_EQ(x1_type, boost::typeindex::type_id_with_cvr<const other_anon&>());
+    static_assert(std::is_same<
+        decltype(boost::pfr::get<1>(x)),
+        const other_anon&
+    >::value, "");
 }

 } // anonymous namespace
@@ -51,5 +47,3 @@ int main() {

    return boost::report_errors();
 }
-
-
--- a/test/core/run/get_non_default_constructible.cpp
+++ b/test/core/run/get_non_default_constructible.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/get_rvalue.cpp
+++ b/test/core/run/get_rvalue.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2025 Antony Polukhin
+// Copyright (c) 2020-2026 Antony Polukhin
 //
 // 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)
@@ -20,8 +20,17 @@ void test_get_rvalue() {
        std::make_unique<int>(43),
    };

+    // Some _MSC_VER are broken:
+    // boost/pfr/detail/fields_count.hpp(469): error C2338: static_assert failed:
+    // '====================> Boost.PFR: If there's no other failed static
+    // asserts then something went wrong. Please report this issue to the github
+    // along with the structure you're reflecting.'
+    //
+    // No known workaround
+#if !defined(_MSC_VER) || _MSC_VER != 1944 || !(BOOST_PFR_USE_CPP17 || BOOST_PFR_USE_LOOPHOLE)
    auto p = boost::pfr::get<0>(std::move(x));
    BOOST_TEST_EQ(*p, 42);
+#endif
 }

 int main() {
--- a/test/core/run/huge_count.cpp
+++ b/test/core/run/huge_count.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2024 Antony Polukhin
+// Copyright (c) 2024-2026 Antony Polukhin
 //
 // 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)
@@ -9,11 +9,7 @@
 #include <cstdint>

 #if defined(__clang__)
-#   if SIZE_MAX > (1ULL << 32) - 1
-#       define ARRAY_MAX (SIZE_MAX >> 3)
-#   else
-#       define ARRAY_MAX SIZE_MAX
-#   endif
+#   define ARRAY_MAX INT_MAX
 #   define OBJECT_MAX SIZE_MAX
 #elif defined(__GNUC__)
 #   define ARRAY_MAX INT_MAX
--- a/test/core/run/is_implicitly_reflectable.cpp
+++ b/test/core/run/is_implicitly_reflectable.cpp
@@ -7,6 +7,10 @@
 #include <boost/pfr/traits.hpp>
 #include <type_traits>  // for std::true_type, std::false_type and std::is_aggregate

+#if defined(BOOST_USE_MODULES) // TODO: fix for BOOST_USE_MODULES
+int main() {}
+
+#else
 namespace boost { namespace pfr {
    struct boost_fusion_tag;
    struct boost_json_tag;
@@ -81,3 +85,5 @@ int main() {
 #endif  // #if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
 }

+#endif
+
--- a/test/core/run/issue30.cpp
+++ b/test/core/run/issue30.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
@@ -9,6 +9,15 @@
 #include <boost/pfr.hpp>
 #include <boost/core/lightweight_test.hpp>

+// Some _MSC_VER are broken:
+// boost/pfr/detail/fields_count.hpp(469): error C2338: static_assert failed:
+// '====================> Boost.PFR: If there's no other failed static
+// asserts then something went wrong. Please report this issue to the github
+// along with the structure you're reflecting.'
+//
+// No known workaround
+#if !defined(_MSC_VER) || _MSC_VER != 1944 || !(BOOST_PFR_USE_CPP17 || BOOST_PFR_USE_LOOPHOLE)
+
 struct Message {
  std::unique_ptr<int> data;
 };
@@ -35,3 +44,9 @@ int main() {

  return boost::report_errors();
 }
+
+#else
+int main() {
+  return boost::report_errors();
+}
+#endif
--- a/test/core/run/issue33.cpp
+++ b/test/core/run/issue33.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2025 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // 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)
@@ -23,7 +23,7 @@ int main() {
 // FIXME: https://github.com/boostorg/pfr/issues/131
 #if defined(__clang__) && __cplusplus >= 202002L

-# if BOOST_PFR_USE_LOOPHOLE == 0 && BOOST_PFR_USE_CPP17 == 0
+# if BOOST_PFR_USE_LOOPHOLE == 0 && BOOST_PFR_USE_CPP17 == 0 && BOOST_PFR_USE_CPP26 == 0
 #   error This test should fail on classic engine
 #endif

--- a/test/core/run/many_fields_count.cpp
+++ b/test/core/run/many_fields_count.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2024 Antony Polukhin
+// Copyright (c) 2024-2026 Antony Polukhin
 //
 // 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)
--- a/test/core/run/motivating_example.cpp
+++ b/test/core/run/motivating_example.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2025 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // 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)
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Antony Polukhin	228922fdb5	Update copyright years	2026-01-04 11:26:11 +03:00
Antony Polukhin	ebcac93bcf	Update CI (#227 )	2025-12-31 14:48:17 +03:00
dependabot[bot]	79a8290374	Bump actions/checkout from 2 to 6 (#226 ) Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 6. - [Release notes](https://github.com/actions/checkout/releases) - [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md) - [Commits](https://github.com/actions/checkout/compare/v2...v6) --- updated-dependencies: - dependency-name: actions/checkout dependency-version: '6' dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-12-31 14:19:43 +03:00
Antony Polukhin	1b0506f44f	Add dependabot	2025-12-24 20:19:28 +03:00
Alexander Grund	7aa41ed4f5	CMake: Condition core_name tests on CMake version (#224 ) As those tests require C++20 only compile them with CMake 3.12+ to be able to use `cxx_std_20`	2025-10-28 19:40:55 +03:00
Alexander Grund	7509049f2c	Fix compatibility with CMake < 3.14 (#223 ) `NAME_WLE` was introduced in 3.14	2025-10-06 19:38:26 +03:00
Antony Polukhin	4f9e6457b0	Add multiple tests from different bug reports and make sure that ever… (#222 ) …ything works with new unsafe_declval and with sturctured binding pack Fixes: https://github.com/boostorg/pfr/issues/208, https://github.com/boostorg/pfr/issues/110, https://github.com/boostorg/pfr/issues/126 Closes: https://github.com/boostorg/pfr/pull/212 Relates: https://github.com/boostorg/pfr/issues/173	2025-09-14 14:59:25 +03:00
Antony Polukhin	fc2dba87d6	Multiple fixes for the structured bindings pack implementation (#221 )	2025-09-11 21:51:07 +03:00
Antony Polukhin	d9fde1f2a0	core: add an implementation based on C++26 destructuring into a pack (#220 ) Tested with clang-21 --------- Co-authored-by: Jean-Michaël Celerier <jeanmichael.celerier@gmail.com>	2025-09-07 20:26:44 +03:00
Antony Polukhin	5034bf55fb	Provide and use an alternative implementation of unsafe_declval (#216 ) References https://github.com/boostorg/pfr/issues/208	2025-06-27 20:46:59 +03:00
Antony Polukhin	8cbffcb7ab	Harden the CI checks for CMake and fix some issues (#215 ) Fixes: https://github.com/boostorg/pfr/issues/214	2025-06-27 20:23:23 +03:00
Antony Polukhin	dcf2deb959	Fix for 'Arrays of Length Zero' compiler extension (#213 )	2025-06-20 15:56:51 +03:00
Antony Polukhin	2e3663d0df	Fix CI tests and docs build (#211 ) Fixes https://github.com/boostorg/pfr/issues/203	2025-06-19 18:36:45 +03:00
Antony Polukhin	7259e35f71	Minor fixes for the misc/strip_boost_namespace.sh	2025-06-19 17:23:29 +03:00
Antony Polukhin	f223709e42	Prepare for the 2.3 release of pfr_non_boost version	2025-06-19 17:09:37 +03:00
Antony Polukhin	f61b90ec59	Update regression test links in Readme	2025-06-18 17:51:35 +03:00
Antony Polukhin	820f56c316	Fix typos (#210 ) Thanks to https://github.com/TryKuhn for highlighting the issues	2025-06-17 10:39:53 +03:00
Antony Polukhin	9bc3cb2af7	Another fix attempt for the CMake build from the root directory of Boost (#209 ) Fixes https://github.com/boostorg/pfr/issues/206	2025-06-17 09:51:17 +03:00
Antony Polukhin	57fa1018b0	Update OSes in CI and run CMake tests (#207 ) Fixes https://github.com/boostorg/pfr/issues/205	2025-06-11 21:40:44 +03:00
Antony Polukhin	db9451143a	Fix build on standards before C++20	2025-05-12 19:53:03 +03:00
Antony Polukhin	8417d4fd2d	Fix test after Boost.TypeIndex modularization	2025-05-12 19:53:03 +03:00
Antony Polukhin	f004e91c9b	Return std::array<std::string_view, 0> type for boost::pfr::names_as_array(empty_struct{}) (fixes #195 )	2025-05-12 19:53:03 +03:00
Antony Polukhin	b95fd86595	Fix CMake tests build fail (fixes #198 ) (#201 )	2025-05-12 17:28:20 +03:00
Antony Polukhin	3e5c474337	Minor fixes for modules (#200 )	2025-04-29 22:04:16 +03:00
Peter Dimov	c902451cc0	Merge pull request #199 from sdarwin/docs Docs: fix import path	2025-04-23 19:01:15 +03:00
sdarwin	1756327d0a	Docs: fix import path	2025-04-18 07:03:07 -06:00
Antony Polukhin	5a48d7456f	Rewrite modules following the new recommended Boost practice (#196 ) Changes: 1) `#include <boost/pfr...` is now implicitly does `import boost.pfr` if the modules are supported 2) CI now tests modules on Ubuntu 24.04 with existing runtime tests 3) Renamed module to `boost.pfr` 4) CMakeLists.txt now uses modules for `Boost::pfr` target if modules are supported 5) All the library internals now have unconditional module level linkage. `1)` allows users to mix `#include <boost/pfr...` and `import boost.pfr` in user code without ODR-violations. Significant differences from https://anarthal.github.io/cppblog/modules3: * PFR uses a `BOOST_PFR_USE_STD_MODULE` macro for `import std;` / `includes` while building module. This allows to use `boost.pfr` module in C++20 and even without usable `std` module.	2025-04-16 09:16:09 +03:00