Fix missing include for unique_ptr. (#125)

Always define is_implicitly_reflectable

.github/workflows/ci.yml

@@ -35,11 +35,12 @@ jobs:
             os: ubuntu-20.04
             cxxflags: "cxxflags=-fsanitize=address,undefined,integer -fno-sanitize-recover=undefined"
             linkflags: "linkflags=-fsanitize=address,undefined,integer"
-          - 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"
+          # To low quota to use
+          #- 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"
 
     runs-on: ${{matrix.os}}
 
@@ -123,10 +124,11 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - toolset: msvc-14.1
-            cxxstd: "14,17,latest"
-            addrmd: 32,64
-            os: windows-2016
+          # TODO: fails the loophole tests
+          #- toolset: msvc
+          #  cxxstd: "14,17,latest"
+          #  addrmd: 32,64
+          #  os: windows-2022
           # TODO: fails the loophole tests
           #- toolset: msvc-14.2
           #  cxxstd: "14,17,latest"

README.md

@@ -45,11 +45,13 @@ Outputs:
 Edgar Allan Poe was born in 1809
 ```
 
+[Run the above sample](https://godbolt.org/z/PfYsWKb7v)
+
 
 ### Motivating Example #1
 ```c++
 #include <iostream>
-#include "boost/pfr/precise.hpp"
+#include "boost/pfr.hpp"
 
 struct my_struct { // no ostream operator defined!
     int i;
@@ -74,7 +76,7 @@ my_struct has 3 fields: {100, H, 3.14159}
 
 ```c++
 #include <iostream>
-#include "boost/pfr/precise.hpp"
+#include "boost/pfr.hpp"
 
 struct my_struct { // no ostream operator defined!
     std::string s;
@@ -94,6 +96,58 @@ Outputs:
 my_struct has 2 fields: {"Das ist fantastisch!", 100}
 ```
 
+### Motivating Example #3
+
+```c++
+#include <iostream>
+#include <string>
+
+#include <boost/config/warning_disable.hpp>
+#include <boost/spirit/home/x3.hpp>
+#include <boost/fusion/include/adapt_boost_pfr.hpp>
+
+#include "boost/pfr/io.hpp"
+
+namespace x3 = boost::spirit::x3;
+
+struct ast_employee { // No BOOST_FUSION_ADAPT_STRUCT defined
+    int age;
+    std::string forename;
+    std::string surname;
+    double salary;
+};
+
+auto const quoted_string = x3::lexeme['"' >> +(x3::ascii::char_ - '"') >> '"'];
+
+x3::rule<class employee, ast_employee> const employee = "employee";
+auto const employee_def =
+    x3::lit("employee")
+    >> '{'
+    >>  x3::int_ >> ','
+    >>  quoted_string >> ','
+    >>  quoted_string >> ','
+    >>  x3::double_
+    >>  '}'
+    ;
+BOOST_SPIRIT_DEFINE(employee);
+
+int main() {
+    std::string str = R"(employee{34, "Chip", "Douglas", 2500.00})";
+    ast_employee emp;
+    x3::phrase_parse(str.begin(),
+                     str.end(),
+                     employee,
+                     x3::ascii::space,
+                     emp);
+    std::cout << boost::pfr::io(emp) << std::endl;
+}
+
+```
+Outputs:
+```
+(34 Chip Douglas 2500)
+```
+
 
 ### Requirements and Limitations
 

doc/Jamfile.v2

@@ -34,7 +34,9 @@ local doxygen_params =
             \"podops=\\b See \\b Also : \\xmlonly<link linkend='boost_pfr.tutorial.three_ways_of_getting_operators'>\\endxmlonly 'Three ways of getting operators' \\xmlonly</link>\\endxmlonly\" \\
             \"customio=\\b See \\b Also : \\xmlonly<link linkend='boost_pfr.tutorial.custom_printing_of_aggregates'>\\endxmlonly 'Custom printing of aggregates' \\xmlonly</link>\\endxmlonly for info on how to implement your own manipulator with custom format.\" \\
             \"aggregate=\\xmlonly<link linkend='boost_pfr.limitations_and_configuration'>\\endxmlonly simple aggregate \\xmlonly</link>\\endxmlonly\" \\
-            \"BOOST_PFR_DOXYGEN_INVOKED\" \\
+        "
+        <doxygen:param>"PREDEFINED= \\
+            \"BOOST_PFR_DOXYGEN_INVOKED=1\" \\
         "
     ;
 
@@ -52,7 +54,7 @@ boostbook pfr-doc
         pfr.qbk
     :
         <dependency>autodoc_pfr
-        <xsl:param>boost.root=https://www.boost.org/doc/libs/1_72_0
+        <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
     ;

doc/pfr.qbk

@@ -1,7 +1,7 @@
 [library Boost.PFR
     [quickbook 1.6]
-    [version 2.0]
-    [copyright 2016-2021 Antony Polukhin]
+    [version 2.1]
+    [copyright 2016-2023 Antony Polukhin]
     [category Language Features Emulation]
     [license
         Distributed under the Boost Software License, Version 1.0.
@@ -17,6 +17,7 @@ Boost.PFR is a C++14 library for a very basic reflection. It gives you access to
 [import ../example/motivating_example0.cpp]
 [pfr_motivating_example]
 
+Experiment with the sample [@https://godbolt.org/z/PfYsWKb7v online].
 See [link boost_pfr.limitations_and_configuration [*limitations]].
 
 
@@ -42,20 +43,20 @@ user_info retrieve_friend(std::string_view name) {
         name
     );
 
-    ////////////////////////////////////////////////////////////////////////////////
+    /////////////////////////////////////////////////////////////////////////////
     user_info info {
         std::move(std::get<0>(info_tuple)),
         std::move(std::get<1>(info_tuple)),
         std::move(std::get<2>(info_tuple)),
         std::move(std::get<3>(info_tuple)),
     }
-    ////////////////////////////////////////////////////////////////////////////////
+    /////////////////////////////////////////////////////////////////////////////
 
     auto friend_info = ask_user_for_friend(std::move(info));
 
     db::insert(
         "INSERT INTO user_infos(id, name, email, login) VALUES ($0, $1, $2, $3)",
-        friend_info.id,    /////////////////////////////////////////////////////////
+        friend_info.id,    //////////////////////////////////////////////////////
         friend_info.name,  // Users are forced to enumerate fields because your
         friend_info.email, // library can not iterate over the fields of a user
         friend_info.login  // provided structure
@@ -80,20 +81,20 @@ user_info retrieve_friend(std::string_view name) {
         name
     );
 
-    ////////////////// No boilerplate code to move data around /////////////////////
+    ////////////////// No boilerplate code to move data around //////////////////
 
 
 
 
 
 
-    ////////////////////////////////////////////////////////////////////////////////
+    /////////////////////////////////////////////////////////////////////////////
 
     auto friend_info = ask_user_for_friend(std::move(info));
 
     db::insert(
         "INSERT INTO user_infos(id, name, email, login) VALUES ($0, $1, $2, $3)",
-        friend_info     ////////////////////////////////////////////////////////////
+        friend_info     /////////////////////////////////////////////////////////
                         // Boost.PFR allows you to iterate over all the fields
                         // of a user provided structure
                         //
@@ -119,7 +120,7 @@ struct user_info {
     std::string name, email, login;
 };
 
-/// Customizations via hand-written code or macro like BOOST_FUSION_ADAPT_STRUCT ///
+/// Customizations via hand-written code ////////////////////////////////////////
 auto db_api_tie(user_info& ui) noexcept {
     return std::tie(ui.id, ui.name, ui.email, ui.login);
 }
@@ -127,7 +128,7 @@ auto db_api_tie(user_info& ui) noexcept {
 auto db_api_tie(const user_info& ui) noexcept {
     return std::tie(ui.id, ui.name, ui.email, ui.login);
 }
-////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////
 ```
 ][
 ```
@@ -138,7 +139,7 @@ struct user_info {
     std::string name, email, login;
 };
 
-//////// With Boost.PFR there's no need in hand written customizations /////////////
+//////// With Boost.PFR there's no need in hand written customizations //////////
 
 
 
@@ -146,14 +147,29 @@ struct user_info {
 
 
 
-////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////
 ```
 ]]
 ]
 
 
+Imagine that you are writing a serialization library. Serialization of user
+provided structures (and nested structures) with Boost.PFR it is just as simple as:
+
+```
+void Write(Writer& writer, int value);
+void Write(Writer& writer, std::string_view value);
+
+template <typename T>
+std::enable_if_t<std::is_aggregate_v<T>> Write(Writer& writer, const T& value) {
+  boost::pfr::for_each_field(
+      value, [&writer](const auto& field) { Write(writer, field); });
+}
+```
+
 With Boost.PFR the code is shorter, more readable and more pleasant to write.
 
+[note All the above examples were inspired by the Boost.PFR usage in [@https://github.com/userver-framework/userver 🐙 userver framework].]
 
 
 [h2 Out of the box functionality ]
@@ -164,10 +180,11 @@ Boost.PFR adds the following out-of-the-box functionality for aggregate initiali
 * heterogeneous comparators
 * hash
 * IO streaming
-* access to members by index
+* access to members by index or type
 * member type retrieval
 * methods for cooperation with `std::tuple`
 * methods to visit each field of the structure
+* trait to detect potential ability to reflect type, and ability to override trait's decision in user-side code
 
 Boost.PFR is a header only library that does not depend on Boost. You can just copy the content of the "include" folder [@https://github.com/boostorg/pfr from the Boost.PFR github] into your project, and the library will work fine. For a version of the library without `boost::` namespace see [@https://github.com/apolukhin/pfr_non_boost PFR].
 
@@ -467,6 +484,8 @@ By default Boost.PFR [*auto-detects your compiler abilities] and automatically d
     [[*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. ]]
     [[*BOOST_PFR_HAS_GUARANTEED_COPY_ELISION*] [Define to `0` if your compiler does not implement C++17 guaranteed copy elision properly and fails to reflect aggregates with non-movable fields. Define to `1` to override Boost.PFR detection logic. ]]
+    [[*BOOST_PFR_ENABLE_IMPLICIT_REFLECTION*] [Define to `0` if you are hit by lots of non-effective choices made by implicitly reflection. Define to `1` to override Boost.PFR detection logic. ]]
+    [[*BOOST_PFR_ENABLED*] [On platforms where Boost.PFR is not supported, the `boost/pfr/config.hpp` header defines the BOOST_PFR_ENABLED macro equal to 0. Defining this macro as 0 before including the header disables the Boost.PFR library. ]]
 ]
 
 
@@ -475,8 +494,8 @@ By default Boost.PFR [*auto-detects your compiler abilities] and automatically d
 The Boost.PFRs reflection has some limitations that depend on a C++ Standard and compiler capabilities:
 
 * Static variables are ignored
-* T must be aggregate initializable without empty base classes
-* if T contains C arrays or it is inherited from non-empty type then the result of reflection may differ depending on the C++ version and library configuration
+* T must be aggregate initializable without base classes
+* if T contains C arrays then the result of reflection may differ depending on the C++ version and library configuration
 * Additional limitations if [*BOOST_PFR_USE_CPP17 == 0]:
     * Non of the member fields should have a template constructor from one parameter.
     * Additional limitations if [*BOOST_PFR_USE_LOOPHOLE == 0]:
@@ -518,7 +537,7 @@ Description of the [*BOOST_PFR_USE_LOOPHOLE == 1] technique by its inventor Alex
 
 [section Acknowledgements]
 
-Many thanks to Bruno Dutra for showing the technique to precisely reflect aggregate initializable type in C++14 [@https://github.com/apolukhin/magic_get/issues/5 Manual type registering/structured bindings might be unnecessary].
+Many thanks to Bruno Dutra for showing the technique to precisely reflect aggregate initializable type in C++14 [@https://github.com/boostorg/pfr/issues/5 Manual type registering/structured bindings might be unnecessary].
 
 Many thanks to Alexandr Poltavsky for initial implementation the [*BOOST_PFR_USE_LOOPHOLE == 1] technique and for describing it [@http://alexpolt.github.io/type-loophole.html in his blog].
 

example/get.cpp

@@ -1,4 +1,4 @@
-// Copyright 2016-2021 Antony Polukhin
+// Copyright 2016-2023 Antony Polukhin
 
 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt

example/motivating_example0.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

example/quick_examples.cpp

@@ -1,4 +1,4 @@
-// Copyright 2016-2021 Antony Polukhin
+// Copyright 2016-2023 Antony Polukhin
 
 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt
@@ -91,7 +91,7 @@ void test_examples() {
 
   {
 //[pfr_quick_examples_get
-    // Get field by index and assign new value to that field
+    // Get field by index/type and assign new value to that field
 
     struct sample {
         char c;
@@ -100,8 +100,9 @@ void test_examples() {
 
     sample var{};
     boost::pfr::get<1>(var) = 42.01f;
+    boost::pfr::get<char>(var) = 'A';
 
-    std::cout << var.f; // Outputs: 42.01
+    std::cout << var.c << var.f; // Outputs: A 42.01
 //]
   }
 

example/sample_printing.cpp

@@ -1,4 +1,4 @@
-// Copyright 2016-2021 Antony Polukhin
+// Copyright 2016-2023 Antony Polukhin
 
 // Distributed under the Boost Software License, Version 1.0.
 // (See the accompanying file LICENSE_1_0.txt

include/boost/pfr.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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 +9,7 @@
 /// \file boost/pfr.hpp
 /// Includes all the Boost.PFR headers
 
+#include <boost/pfr/config.hpp>
 #include <boost/pfr/core.hpp>
 #include <boost/pfr/functions_for.hpp>
 #include <boost/pfr/functors.hpp>
@@ -17,5 +18,7 @@
 #include <boost/pfr/ops.hpp>
 #include <boost/pfr/ops_fields.hpp>
 #include <boost/pfr/tuple_size.hpp>
+#include <boost/pfr/traits_fwd.hpp>
+#include <boost/pfr/traits.hpp>
 
 #endif // BOOST_PFR_HPP

include/boost/pfr/config.hpp

@@ -0,0 +1,121 @@
+// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#ifndef BOOST_PFR_CONFIG_HPP
+#define BOOST_PFR_CONFIG_HPP
+#pragma once
+
+#if __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
+
+/// \file boost/pfr/config.hpp
+/// Contains all the macros that describe Boost.PFR configuration, like BOOST_PFR_ENABLED
+///
+/// \note This header file doesn't require C++14 Standard and supports all C++ compilers, even pre C++14 compilers (C++11, C++03...).
+
+// Reminder:
+//  * MSVC++ 14.2 _MSC_VER == 1927 <- Loophole is known to work (Visual Studio ????)
+//  * MSVC++ 14.1 _MSC_VER == 1916 <- Loophole is known to NOT work (Visual Studio 2017)
+//  * MSVC++ 14.0 _MSC_VER == 1900 (Visual Studio 2015)
+//  * MSVC++ 12.0 _MSC_VER == 1800 (Visual Studio 2013)
+
+#ifdef BOOST_PFR_NOT_SUPPORTED
+#   error Please, do not set BOOST_PFR_NOT_SUPPORTED value manually, use '-DBOOST_PFR_ENABLED=0' instead of it
+#endif
+
+#if defined(_MSC_VER)
+#   if !defined(_MSVC_LANG) || _MSC_VER <= 1900
+#       define BOOST_PFR_NOT_SUPPORTED 1
+#   endif
+#elif __cplusplus < 201402L
+#   define BOOST_PFR_NOT_SUPPORTED 1
+#endif
+
+#ifndef BOOST_PFR_USE_LOOPHOLE
+#   if defined(_MSC_VER)
+#       if _MSC_VER >= 1927
+#           define BOOST_PFR_USE_LOOPHOLE 1
+#       else
+#           define BOOST_PFR_USE_LOOPHOLE 0
+#       endif
+#   elif defined(__clang_major__) && __clang_major__ >= 8
+#       define BOOST_PFR_USE_LOOPHOLE 0
+#   else
+#       define BOOST_PFR_USE_LOOPHOLE 1
+#   endif
+#endif
+
+#ifndef BOOST_PFR_USE_CPP17
+#   ifdef __cpp_structured_bindings
+#       define BOOST_PFR_USE_CPP17 1
+#   elif defined(_MSVC_LANG)
+#       if _MSVC_LANG >= 201703L
+#           define BOOST_PFR_USE_CPP17 1
+#       else
+#           define BOOST_PFR_USE_CPP17 0
+#       endif
+#   else
+#       define BOOST_PFR_USE_CPP17 0
+#   endif
+#endif
+
+#if (!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
+// Assume that libstdc++ since GCC-7.3 does not have linear instantiation depth in std::make_integral_sequence
+#   if 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
+//# elif other known working lib
+#   else
+#       define BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE 0
+#   endif
+#endif
+
+#ifndef BOOST_PFR_HAS_GUARANTEED_COPY_ELISION
+#   if  defined(__cpp_guaranteed_copy_elision) && (!defined(_MSC_VER) || _MSC_VER > 1928)
+#       define BOOST_PFR_HAS_GUARANTEED_COPY_ELISION 1
+#   else
+#       define BOOST_PFR_HAS_GUARANTEED_COPY_ELISION 0
+#   endif
+#endif
+
+#ifndef BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+#   if  defined(__cpp_lib_is_aggregate)
+#       define BOOST_PFR_ENABLE_IMPLICIT_REFLECTION 1
+#   else
+// There is no way to detect potential ability to be reflectable without std::is_aggregare
+#       define BOOST_PFR_ENABLE_IMPLICIT_REFLECTION 0
+#   endif
+#endif
+
+#if defined(__has_cpp_attribute)
+#   if __has_cpp_attribute(maybe_unused)
+#       define BOOST_PFR_MAYBE_UNUSED [[maybe_unused]]
+#   endif
+#endif
+
+#ifndef BOOST_PFR_MAYBE_UNUSED
+#   define BOOST_PFR_MAYBE_UNUSED
+#endif
+
+#ifndef BOOST_PFR_ENABLED
+#   ifdef BOOST_PFR_NOT_SUPPORTED
+#       define BOOST_PFR_ENABLED 0
+#   else
+#       define BOOST_PFR_ENABLED 1
+#   endif
+#endif
+
+#undef BOOST_PFR_NOT_SUPPORTED
+
+#endif // BOOST_PFR_CONFIG_HPP

include/boost/pfr/core.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -30,20 +30,25 @@
 namespace boost { namespace pfr {
 
 /// \brief Returns reference or const reference to a field with index `I` in \aggregate `val`.
+/// Overload taking the type `U` returns reference or const reference to a field
+/// with provided type `U` in \aggregate `val` if there's only one field of such type in `val`.
 ///
 /// \b Example:
 /// \code
 ///     struct my_struct { int i, short s; };
 ///     my_struct s {10, 11};
+///
 ///     assert(boost::pfr::get<0>(s) == 10);
 ///     boost::pfr::get<1>(s) = 0;
+///
+///     assert(boost::pfr::get<int>(s) == 10);
+///     boost::pfr::get<short>(s) = 11;
 /// \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) );
 }
 
-
 /// \overload get
 template <std::size_t I, class T>
 constexpr decltype(auto) get(T& val
@@ -66,11 +71,45 @@ 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>* = 0) noexcept {
+constexpr auto get(T&& val, std::enable_if_t< std::is_rvalue_reference<T&&>::value>* = nullptr) noexcept {
     return std::move(detail::sequence_tuple::get<I>( detail::tie_as_tuple(val) ));
 }
 
 
+/// \overload get
+template <class U, class T>
+constexpr const U& get(const T& val) noexcept {
+    return detail::sequence_tuple::get_by_type_impl<const U&>( detail::tie_as_tuple(val) );
+}
+
+
+/// \overload get
+template <class U, class T>
+constexpr U& get(T& val
+#if !BOOST_PFR_USE_CPP17
+    , 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
+/// \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");
+    return 0;
+}
+#endif
+
+
+/// \overload get
+template <class U, class T>
+constexpr U&& get(T&& val, std::enable_if_t< std::is_rvalue_reference<T&&>::value>* = nullptr) noexcept {
+    return std::move(detail::sequence_tuple::get_by_type_impl<U&>( detail::tie_as_tuple(val) ));
+}
+
+
 /// \brief `tuple_element` has a member typedef `type` that returns the type of a field with index I in \aggregate T.
 ///
 /// \b Example:
@@ -97,7 +136,7 @@ using tuple_element_t = typename tuple_element<I, T>::type;
 /// \code
 ///     struct my_struct { int i, short s; };
 ///     my_struct s {10, 11};
-///     std::tuple<int, short> t = make_tuple(s);
+///     std::tuple<int, short> t = boost::pfr::structure_to_tuple(s);
 ///     assert(get<0>(t) == 10);
 /// \endcode
 template <class T>
@@ -119,10 +158,10 @@ constexpr auto structure_to_tuple(const T& val) noexcept {
 ///     struct my_struct { int i, short s; };
 ///
 ///     const my_struct const_s{1, 2};
-///     std::apply(foo, structure_tie(const_s));
+///     std::apply(foo, boost::pfr::structure_tie(const_s));
 ///
 ///     my_struct s;
-///     structure_tie(s) = std::tuple<int, short>{10, 11};
+///     boost::pfr::structure_tie(s) = std::tuple<int, short>{10, 11};
 ///     assert(s.s == 11);
 /// \endcode
 template <class T>
@@ -159,7 +198,7 @@ constexpr auto structure_tie(T&, std::enable_if_t<!std::is_assignable<T, T>::val
 
 /// \overload structure_tie
 template <class T>
-constexpr auto structure_tie(T&&, std::enable_if_t< std::is_rvalue_reference<T&&>::value>* = 0) noexcept {
+constexpr auto structure_tie(T&&, std::enable_if_t< std::is_rvalue_reference<T&&>::value>* = nullptr) noexcept {
     static_assert(sizeof(T) && false, "====================> Boost.PFR: Calling boost::pfr::structure_tie on rvalue references is forbidden");
     return 0;
 }
@@ -177,7 +216,7 @@ constexpr auto structure_tie(T&&, std::enable_if_t< std::is_rvalue_reference<T&&
 /// \code
 ///     struct my_struct { int i, short s; };
 ///     int sum = 0;
-///     for_each_field(my_struct{20, 22}, [&sum](const auto& field) { sum += field; });
+///     boost::pfr::for_each_field(my_struct{20, 22}, [&sum](const auto& field) { sum += field; });
 ///     assert(sum == 42);
 /// \endcode
 template <class T, class F>
@@ -214,7 +253,7 @@ void for_each_field(T&& value, F&& func) {
 ///       return res;
 ///     }
 ///     auto [p, s] = f();
-///     tie_from_structure(p, s) = f();
+///     boost::pfr::tie_from_structure(p, s) = f();
 /// \endcode
 template <typename... Elements>
 constexpr detail::tie_from_structure_tuple<Elements...> tie_from_structure(Elements&... args) noexcept {

include/boost/pfr/detail/cast_to_layout_compatible.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/config.hpp

@@ -1,4 +1,5 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2022 Denis Mikhailov
 //
 // 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)
@@ -7,85 +8,19 @@
 #define BOOST_PFR_DETAIL_CONFIG_HPP
 #pragma once
 
-#include <type_traits> // to get non standard platform macro definitions (__GLIBCXX__ for example)
+#include <boost/pfr/config.hpp>
 
-// Reminder:
-//  * MSVC++ 14.2 _MSC_VER == 1927 <- Loophole is known to work (Visual Studio ????)
-//  * MSVC++ 14.1 _MSC_VER == 1916 <- Loophole is known to NOT work (Visual Studio 2017)
-//  * MSVC++ 14.0 _MSC_VER == 1900 (Visual Studio 2015)
-//  * MSVC++ 12.0 _MSC_VER == 1800 (Visual Studio 2013)
+#if !BOOST_PFR_ENABLED
 
-#if defined(_MSC_VER)
-#   if !defined(_MSVC_LANG) || _MSC_VER <= 1900
-#       error Boost.PFR library requires more modern MSVC compiler.
-#   endif
-#elif __cplusplus < 201402L
-#   error Boost.PFR library requires at least C++14.
-#endif
-
-#ifndef BOOST_PFR_USE_LOOPHOLE
-#   if defined(_MSC_VER)
-#       if _MSC_VER >= 1927
-#           define BOOST_PFR_USE_LOOPHOLE 1
-#       else
-#           define BOOST_PFR_USE_LOOPHOLE 0
-#       endif
-#   elif defined(__clang_major__) && __clang_major__ >= 8
-#       define BOOST_PFR_USE_LOOPHOLE 0
-#   else
-#       define BOOST_PFR_USE_LOOPHOLE 1
-#   endif
-#endif
-
-#ifndef BOOST_PFR_USE_CPP17
-#   ifdef __cpp_structured_bindings
-#       define BOOST_PFR_USE_CPP17 1
-#   elif defined(_MSVC_LANG)
-#       if _MSVC_LANG >= 201703L
-#           define BOOST_PFR_USE_CPP17 1
-#       else
-#           define BOOST_PFR_USE_CPP17 0
-#       endif
-#   else
-#       define BOOST_PFR_USE_CPP17 0
-#   endif
-#endif
-
-#if (!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
-#      error Boost.PFR requires /std:c++latest or /std:c++17 flags on your compiler.
-#   endif
-#endif
-
-#ifndef BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE
-// Assume that libstdc++ since GCC-7.3 does not have linear instantiation depth in std::make_integral_sequence
-#   if 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
-//# elif other known working lib
-#   else
-#       define BOOST_PFR_USE_STD_MAKE_INTEGRAL_SEQUENCE 0
-#   endif
-#endif
-
-#ifndef BOOST_PFR_HAS_GUARANTEED_COPY_ELISION
-#   if  defined(__cpp_guaranteed_copy_elision) && (!defined(_MSC_VER) || _MSC_VER > 1928)
-#       define BOOST_PFR_HAS_GUARANTEED_COPY_ELISION 1
-#   else
-#       define BOOST_PFR_HAS_GUARANTEED_COPY_ELISION 0
-#   endif
-#endif
-
-#if defined(__has_cpp_attribute)
-#   if __has_cpp_attribute(maybe_unused)
-#       define BOOST_PFR_MAYBE_UNUSED [[maybe_unused]]
-#   endif
-#endif
-
-#ifndef BOOST_PFR_MAYBE_UNUSED
-#   define BOOST_PFR_MAYBE_UNUSED
-#endif
+#error Boost.PFR library is not supported in your environment.             \
+       Try one of the possible solutions:                                  \
+       1. try to take away an '-DBOOST_PFR_ENABLED=0', if it exists        \
+       2. enable C++14;                                                    \
+       3. enable C++17;                                                    \
+       4. update your compiler;                                            \
+       or disable this error by '-DBOOST_PFR_ENABLED=1' if you really know what are you doing.
 
+#endif // !BOOST_PFR_ENABLED
 
 #endif // BOOST_PFR_DETAIL_CONFIG_HPP
+

include/boost/pfr/detail/core.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/core14_classic.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -53,7 +53,7 @@ namespace typeid_conversions {
 #ifdef _MSC_VER
 #   pragma warning( push )
     // '<<': check operator precedence for possible error; use parentheses to clarify precedence
-#   pragma warning( disable : 4554 ) 
+#   pragma warning( disable : 4554 )
 #endif
 
 constexpr std::size_t native_types_mask = 31;
@@ -118,16 +118,16 @@ template <class Type> constexpr std::size_t type_to_id(identity<const Type*>) no
 template <class Type> constexpr std::size_t type_to_id(identity<const volatile Type*>) noexcept;
 template <class Type> constexpr std::size_t type_to_id(identity<volatile Type*>) noexcept;
 template <class Type> constexpr std::size_t type_to_id(identity<Type&>) noexcept;
-template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_enum<Type>::value>* = 0) noexcept;
-template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_empty<Type>::value>* = 0) noexcept;
-template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_union<Type>::value>* = 0) noexcept;
+template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_enum<Type>::value>* = nullptr) noexcept;
+template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_empty<Type>::value>* = nullptr) noexcept;
+template <class Type> constexpr std::size_t type_to_id(identity<Type>, std::enable_if_t<std::is_union<Type>::value>* = nullptr) noexcept;
 template <class Type> constexpr size_array<sizeof(Type) * 3> type_to_id(identity<Type>, std::enable_if_t<!std::is_enum<Type>::value && !std::is_empty<Type>::value && !std::is_union<Type>::value>* = 0) noexcept;
 
-template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_const_ptr_type> = 0) noexcept;
-template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_ptr_type> = 0) noexcept;
-template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_const_volatile_ptr_type> = 0) noexcept;
-template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_volatile_ptr_type> = 0) noexcept;
-template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_ref_type> = 0) noexcept;
+template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_const_ptr_type> = nullptr) noexcept;
+template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_ptr_type> = nullptr) noexcept;
+template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_const_volatile_ptr_type> = nullptr) noexcept;
+template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_volatile_ptr_type> = nullptr) noexcept;
+template <std::size_t Index> constexpr auto id_to_type(size_t_<Index >, if_extension<Index, native_ref_type> = nullptr) noexcept;
 
 
 ///////////////////// Definitions of type_to_id and id_to_type for fundamental types
@@ -599,13 +599,20 @@ struct ubiq_constructor_constexpr_copy {
 /////////////////////
 
 template <class T, std::size_t... I>
-struct is_constexpr_aggregate_initializable { // TODO: try to fix it
-    template <T = T{ ubiq_constructor_constexpr_copy{I}... } >
+struct is_constexpr_aggregate_initializable {
+    template<class T2, std::size_t... I2>
+    static constexpr void* constexpr_aggregate_initializer() noexcept {
+        T2 tmp{ ubiq_constructor_constexpr_copy{I2}... };
+        (void)tmp;
+        return nullptr;
+    }
+
+    template <void* = constexpr_aggregate_initializer<T, I...>() >
     static std::true_type test(long) noexcept;
 
     static std::false_type test(...) noexcept;
 
-    static constexpr decltype( test(0) ) value{};
+    static constexpr bool value = decltype(test(0)){};
 };
 
 
@@ -676,16 +683,7 @@ void for_each_field_dispatcher(T& t, F&& f, std::index_sequence<I...>) {
         !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."
     );
-
-    /// Compile time error at this point means that you have called `for_each_field` or some other non-flat function or operator for a
-    /// type that is not constexpr aggregate initializable.
-    ///
-    /// Make sure that all the fields of your type have constexpr default construtors and trivial destructors.
-    /// Or compile in C++17 mode.
-    constexpr T tmp{ ubiq_constructor_constexpr_copy{I}... };
-    (void)tmp;
-
-    //static_assert(is_constexpr_aggregate_initializable<T, I...>::value, "====================> Boost.PFR: T must be a constexpr initializable type");
+    static_assert(is_constexpr_aggregate_initializable<T, I...>::value, "====================> Boost.PFR: T must be a constexpr initializable type");
 
     constexpr bool is_flat_refelectable_val = detail::is_flat_refelectable<T>( std::index_sequence<I...>{} );
     detail::for_each_field_dispatcher_1(

include/boost/pfr/detail/core14_loophole.hpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2017-2018 Alexandr Poltavsky, Antony Polukhin.
-// Copyright (c) 2019-2021 Antony Polukhin.
+// Copyright (c) 2019-2023 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)
@@ -8,7 +8,7 @@
 // The Great Type Loophole (C++14)
 // Initial implementation by Alexandr Poltavsky, http://alexpolt.github.io
 //
-// Description: 
+// Description:
 //  The Great Type Loophole is a technique that allows to exchange type information with template
 //  instantiations. Basically you can assign and read type information during compile time.
 //  Here it is used to detect data members of a data type. I described it for the first time in
@@ -20,6 +20,7 @@
 
 #ifndef BOOST_PFR_DETAIL_CORE14_LOOPHOLE_HPP
 #define BOOST_PFR_DETAIL_CORE14_LOOPHOLE_HPP
+#pragma once
 
 #include <boost/pfr/detail/config.hpp>
 

include/boost/pfr/detail/core17.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -6,6 +6,7 @@
 
 #ifndef BOOST_PFR_DETAIL_CORE17_HPP
 #define BOOST_PFR_DETAIL_CORE17_HPP
+#pragma once
 
 #include <boost/pfr/detail/core17_generated.hpp>
 #include <boost/pfr/detail/fields_count.hpp>
@@ -22,7 +23,7 @@ struct do_not_define_std_tuple_size_for_me {
 template <class T>
 constexpr bool do_structured_bindings_work() noexcept { // ******************************************* IN CASE OF ERROR READ THE FOLLOWING LINES IN boost/pfr/detail/core17.hpp FILE:
     T val{};
-    const auto& [a] = val; // ******************************************* IN CASE OF ERROR READ THE FOLLOWING LINES IN boost/pfr/detail/core17.hpp FILE:
+    auto& [a] = val; // ******************************************* IN CASE OF ERROR READ THE FOLLOWING LINES IN boost/pfr/detail/core17.hpp FILE:
 
     /****************************************************************************
     *

include/boost/pfr/detail/detectors.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/fields_count.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/for_each_field_impl.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -29,6 +29,7 @@ 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
 template <class T, class F, std::size_t... I>
 void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::false_type /*move_values*/) {
      const int v[] = {0, (
@@ -47,6 +48,17 @@ void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::true_type
      )...};
      (void)v;
 }
+#else
+template <class T, class F, std::size_t... I>
+void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::false_type /*move_values*/) {
+     (detail::for_each_field_impl_apply(sequence_tuple::get<I>(t), std::forward<F>(f), size_t_<I>{}, 1L), ...);
+}
+
+template <class T, class F, std::size_t... I>
+void for_each_field_impl(T& t, F&& f, std::index_sequence<I...>, std::true_type /*move_values*/) {
+     (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
 

include/boost/pfr/detail/functional.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/io.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/make_flat_tuple_of_references.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/make_integer_sequence.hpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Sergei Fedorov
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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)

include/boost/pfr/detail/offset_based_getter.hpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2017-2018 Chris Beck
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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)

include/boost/pfr/detail/possible_reflectable.hpp

@@ -0,0 +1,49 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#ifndef BOOST_PFR_DETAIL_POSSIBLE_REFLECTABLE_HPP
+#define BOOST_PFR_DETAIL_POSSIBLE_REFLECTABLE_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+#include <boost/pfr/traits_fwd.hpp>
+
+#include <type_traits> // for std::is_aggregate
+
+namespace boost { namespace pfr { namespace detail {
+
+///////////////////// Returns false when the type exactly wasn't be reflectable
+template <class T, class WhatFor>
+constexpr decltype(is_reflectable<T, WhatFor>::value) possible_reflectable(long) noexcept {
+    return is_reflectable<T, WhatFor>::value;
+}
+
+#if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+
+template <class T, class WhatFor>
+constexpr bool possible_reflectable(int) noexcept {
+#   if  defined(__cpp_lib_is_aggregate)
+    using type = std::remove_cv_t<T>;
+    return std::is_aggregate<type>();
+#   else
+    return true;
+#   endif
+}
+
+#else
+
+template <class T, class WhatFor>
+constexpr bool possible_reflectable(int) noexcept {
+    // negative answer here won't change behaviour in PFR-dependent libraries(like Fusion)
+    return false;
+}
+
+#endif
+
+}}} // namespace boost::pfr::detail
+
+#endif // BOOST_PFR_DETAIL_POSSIBLE_REFLECTABLE_HPP
+
+

include/boost/pfr/detail/rvalue_t.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/sequence_tuple.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -50,30 +50,74 @@ struct tuple_base<std::index_sequence<> > {
 
 template <std::size_t N, class T>
 constexpr T& get_impl(base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
     return t.value;
 }
 
 template <std::size_t N, class T>
 constexpr const T& get_impl(const base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
     return t.value;
 }
 
 template <std::size_t N, class T>
 constexpr volatile T& get_impl(volatile base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
     return t.value;
 }
 
 template <std::size_t N, class T>
 constexpr const volatile T& get_impl(const volatile base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
     return t.value;
 }
 
 template <std::size_t N, class T>
 constexpr T&& get_impl(base_from_member<N, T>&& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
     return std::forward<T>(t.value);
 }
 
 
+template <class T, std::size_t N>
+constexpr T& get_by_type_impl(base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return t.value;
+}
+
+template <class T, std::size_t N>
+constexpr const T& get_by_type_impl(const base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return t.value;
+}
+
+template <class T, std::size_t N>
+constexpr volatile T& get_by_type_impl(volatile base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return t.value;
+}
+
+template <class T, std::size_t N>
+constexpr const volatile T& get_by_type_impl(const volatile base_from_member<N, T>& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return t.value;
+}
+
+template <class T, std::size_t N>
+constexpr T&& get_by_type_impl(base_from_member<N, T>&& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return std::forward<T>(t.value);
+}
+
+template <class T, std::size_t N>
+constexpr const T&& get_by_type_impl(const base_from_member<N, T>&& t) noexcept {
+    // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
+    return std::forward<T>(t.value);
+}
+
+
+
+
 template <class ...Values>
 struct tuple: tuple_base<
     detail::index_sequence_for<Values...>,

include/boost/pfr/detail/size_array.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/size_t_.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/stdtuple.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/detail/tie_from_structure_tuple.hpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Adam Butcher, Antony Polukhin
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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)

include/boost/pfr/detail/unsafe_declval.hpp

@@ -1,10 +1,11 @@
-// Copyright (c) 2019-2021 Antony Polukhin.
+// Copyright (c) 2019-2023 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)
 
 #ifndef BOOST_PFR_DETAIL_UNSAFE_DECLVAL_HPP
 #define BOOST_PFR_DETAIL_UNSAFE_DECLVAL_HPP
+#pragma once
 
 #include <boost/pfr/detail/config.hpp>
 
@@ -24,7 +25,7 @@ template <class T>
 constexpr T unsafe_declval() noexcept {
     report_if_you_see_link_error_with_this_function();
 
-    typename std::remove_reference<T>::type* ptr = 0;
+    typename std::remove_reference<T>::type* ptr = nullptr;
     ptr += 42; // suppresses 'null pointer dereference' warnings
     return static_cast<T>(*ptr);
 }

include/boost/pfr/functions_for.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/functors.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/io.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -89,17 +89,17 @@ enable_istreamable_t<std::basic_istream<Char, Traits>, T> operator>>(std::basic_
 
 } // namespace detail
 
-/// IO manupulator to read/write \aggregate `value` using its IO stream operators or using \forcedlink{io_fields} if operators are not awailable.
+/// IO manipulator to read/write \aggregate `value` using its IO stream operators or using \forcedlink{io_fields} if operators are not available.
 ///
 /// \b Example:
 /// \code
 ///     struct my_struct { int i; short s; };
-///     my_struct s;
+///     my_struct x;
 ///     std::stringstream ss;
 ///     ss << "{ 12, 13 }";
-///     ss >> boost::pfr::io(s);
-///     assert(s.i == 12);
-///     assert(s.i == 13);
+///     ss >> boost::pfr::io(x);
+///     assert(x.i == 12);
+///     assert(x.s == 13);
 /// \endcode
 ///
 /// \customio

include/boost/pfr/io_fields.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
@@ -21,7 +21,7 @@
 #include <boost/pfr/tuple_size.hpp>
 
 /// \file boost/pfr/io_fields.hpp
-/// Contains IO manupulator \forcedlink{io_fields} to read/write \aggregate `value` field-by-field.
+/// Contains IO manipulator \forcedlink{io_fields} to read/write any \aggregate field-by-field.
 ///
 /// \b Example:
 /// \code
@@ -132,7 +132,7 @@ std::basic_istream<Char, Traits>& operator>>(std::basic_istream<Char, Traits>& i
 
 } // namespace detail
 
-/// IO manupulator to read/write \aggregate `value` field-by-field.
+/// IO manipulator to read/write \aggregate `value` field-by-field.
 ///
 /// \b Example:
 /// \code

include/boost/pfr/ops.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/ops_fields.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)

include/boost/pfr/traits.hpp

@@ -0,0 +1,60 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#ifndef BOOST_PFR_TRAITS_HPP
+#define BOOST_PFR_TRAITS_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+
+#include <boost/pfr/detail/possible_reflectable.hpp>
+#include <type_traits>
+
+/// \file boost/pfr/traits.hpp
+/// Contains traits \forcedlink{is_reflectable} and \forcedlink{is_implicitly_reflectable} for detecting an ability to reflect type.
+///
+/// \b Synopsis:
+
+namespace boost { namespace pfr {
+
+/// Has a static const member variable `value` when it is known that type T can or can't be reflected using Boost.PFR; otherwise, there is no member variable.
+/// Every user may (and in some difficult cases - should) specialize is_reflectable on his own.
+///
+/// \b Example:
+/// \code
+///     namespace boost { namespace pfr {
+///         template<class All> struct is_reflectable<A, All> : std::false_type {};       // 'A' won't be interpreted as reflectable everywhere
+///         template<> struct is_reflectable<B, boost_fusion_tag> : std::false_type {};   // 'B' won't be interpreted as reflectable in only Boost Fusion
+///     }}
+/// \endcode
+/// \note is_reflectable affects is_implicitly_reflectable, the decision made by is_reflectable is used by is_implicitly_reflectable.
+template<class T, class WhatFor>
+struct is_reflectable { /*  does not have 'value' because value is unknown */ };
+
+// these specs can't be inherited from 'std::integral_constant< bool, boost::pfr::is_reflectable<T, WhatFor>::value >',
+// because it will break the sfinae-friendliness
+template<class T, class WhatFor>
+struct is_reflectable<const T, WhatFor> : boost::pfr::is_reflectable<T, WhatFor> {};
+
+template<class T, class WhatFor>
+struct is_reflectable<volatile T, WhatFor> : boost::pfr::is_reflectable<T, WhatFor> {};
+
+template<class T, class WhatFor>
+struct is_reflectable<const volatile T, WhatFor> : boost::pfr::is_reflectable<T, WhatFor> {};
+
+/// Checks the input type for the potential to be reflected.
+/// Specialize is_reflectable if you disagree with is_implicitly_reflectable's default decision.
+template<class T, class WhatFor>
+using is_implicitly_reflectable = std::integral_constant< bool, boost::pfr::detail::possible_reflectable<T, WhatFor>(1L) >;
+
+/// Checks the input type for the potential to be reflected.
+/// Specialize is_reflectable if you disagree with is_implicitly_reflectable_v's default decision.
+template<class T, class WhatFor>
+constexpr bool is_implicitly_reflectable_v = is_implicitly_reflectable<T, WhatFor>::value;
+
+}} // namespace boost::pfr
+
+#endif // BOOST_PFR_TRAITS_HPP
+

include/boost/pfr/traits_fwd.hpp

@@ -0,0 +1,21 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#ifndef BOOST_PFR_DETAIL_TRAITS_FWD_HPP
+#define BOOST_PFR_DETAIL_TRAITS_FWD_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+
+namespace boost { namespace pfr {
+
+template<class T, class WhatFor>
+struct is_reflectable;
+
+}} // namespace boost::pfr
+
+#endif // BOOST_PFR_DETAIL_TRAITS_FWD_HPP
+
+

include/boost/pfr/tuple_size.hpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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 @@
 namespace boost { namespace pfr {
 
 /// Has a static const member variable `value` that contains fields count in a T.
-/// Works for any T that supports aggregate initialization.
+/// Works for any T that satisfies \aggregate.
 ///
 /// \b Example:
 /// \code
@@ -34,7 +34,7 @@ using tuple_size = detail::size_t_< boost::pfr::detail::fields_count<T>() >;
 
 
 /// `tuple_size_v` is a template variable that contains fields count in a T and
-/// works for any T that supports aggregate initialization.
+/// works for any T that satisfies \aggregate.
 ///
 /// \b Example:
 /// \code

index.html

@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <!--
- Copyright (c) 2014-2021 Antony Polukhin
+ Copyright (c) 2014-2023 Antony Polukhin
  antoshkka at gmail dot com
 
  Distributed under the Boost Software License,
@@ -29,7 +29,7 @@
     <a href="https://www.boost.org/doc/libs/master/doc/html/boost_pfr.html">https://www.boost.org/doc/libs/master/doc/html/boost_pfr.html</a>
   </p>
   <p>
-    &copy; 2014-2021 Antony Polukhin
+    &copy; 2014-2023 Antony Polukhin
   </p>
 </body>
 </html>

misc/generate_cpp17.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python
 
-# Copyright (c) 2016-2021 Antony Polukhin
+# Copyright (c) 2016-2023 Antony Polukhin
+# Copyright (c) 2023 Denis Mikhailov
 #
 # 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)
@@ -12,8 +13,10 @@ import string
 
 # Skipping some letters that may produce keywords or are hard to read, or shadow template parameters
 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) 2016-2020 Antony Polukhin
+PROLOGUE = """// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2023 Denis Mikhailov
 //
 // 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)
@@ -35,6 +38,7 @@ PROLOGUE = """// Copyright (c) 2016-2020 Antony Polukhin
 
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/size_t_.hpp>
+#include <type_traits> // for std::conditional_t, std::is_reference
 
 namespace boost { namespace pfr { namespace detail {
 
@@ -43,20 +47,43 @@ constexpr auto make_tuple_of_references(Args&&... args) noexcept {
   return sequence_tuple::tuple<Args&...>{ args... };
 }
 
+template<typename T, typename Arg>
+constexpr decltype(auto) add_cv_like(Arg& arg) noexcept {
+    if constexpr (std::is_const<T>::value && std::is_volatile<T>::value) {
+        return const_cast<const volatile Arg&>(arg);
+    }
+    else if constexpr (std::is_const<T>::value) {
+        return const_cast<const Arg&>(arg);
+    }
+    else if constexpr (std::is_volatile<T>::value) {
+        return const_cast<volatile Arg&>(arg);
+    }
+    else {
+        return const_cast<Arg&>(arg);
+    }
+}
+
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78939
+template<typename T, typename Sb, typename Arg>
+constexpr decltype(auto) workaround_cast(Arg& arg) noexcept {
+    using output_arg_t = std::conditional_t<!std::is_reference<Sb>(), decltype(detail::add_cv_like<T>(arg)), Sb>;
+    return const_cast<output_arg_t>(arg);
+}
+
 template <class T>
 constexpr auto tie_as_tuple(T& /*val*/, size_t_<0>) noexcept {
   return sequence_tuple::tuple<>{};
 }
 
 template <class T>
-constexpr auto tie_as_tuple(T& val, size_t_<1>, std::enable_if_t<std::is_class< std::remove_cv_t<T> >::value>* = 0) noexcept {
-  auto& [a] = val; // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.
-  return ::boost::pfr::detail::make_tuple_of_references(a);
+constexpr auto tie_as_tuple(T& val, size_t_<1>, std::enable_if_t<std::is_class< std::remove_cv_t<T> >::value>* = nullptr) noexcept {
+  auto& [a] = const_cast<std::remove_cv_t<T>&>(val); // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.
+  return ::boost::pfr::detail::make_tuple_of_references(detail::workaround_cast<T, decltype(a)>(a));
 }
 
 
 template <class T>
-constexpr auto tie_as_tuple(T& val, size_t_<1>, std::enable_if_t<!std::is_class< std::remove_cv_t<T> >::value>* = 0) noexcept {
+constexpr auto tie_as_tuple(T& val, size_t_<1>, std::enable_if_t<!std::is_class< std::remove_cv_t<T> >::value>* = nullptr) noexcept {
   return ::boost::pfr::detail::make_tuple_of_references( val );
 }
 
@@ -77,6 +104,33 @@ constexpr void tie_as_tuple(T& /*val*/, size_t_<I>) noexcept {
 
 ############################################################################################################################
 
+def fold_workaround_cast(indexes, divider):
+    WORKAROUND_CAST_TEMPLATE = """
+detail::workaround_cast<T, decltype({arg})>({arg})
+"""
+    lines = []
+    div = ''
+    tokens = [x.strip() for x in indexes.split(',')]
+    casts = [WORKAROUND_CAST_TEMPLATE.strip().format(arg=tok)
+             for tok in tokens]
+    for i in range(0, len(casts)):
+        if i%WORKAROUND_CAST_EXPRESSIONS_LIMIT_PER_LINE==0:
+            div = ''
+            lines.append('')
+        lines[-1] += div + casts[i]
+        div = ','
+    return divider.join(lines)
+
+def calc_indexes_count(indexes):
+    tokens = [x.strip() for x in indexes.split(',')]
+    return len(tokens)
+
+class EmptyLinePrinter:
+    def print_once(self):
+        if not self.printed:
+            print("")
+            self.printed = True
+    printed = False
 
 indexes = "    a"
 print(PROLOGUE)
@@ -92,18 +146,26 @@ for i in range(1, funcs_count):
         indexes += ascii_letters[i // max_args_on_a_line - 1]
     indexes += ascii_letters[i % max_args_on_a_line]
 
+    printed_casts = fold_workaround_cast(indexes.strip(), ",\n    ")
+    indexes_count = calc_indexes_count(indexes.strip())
+    empty_printer = EmptyLinePrinter()
+
     print("template <class T>")
     print("constexpr auto tie_as_tuple(T& val, size_t_<" + str(i + 1) + ">) noexcept {")
     if i < max_args_on_a_line:
-        print("  auto& [" + indexes.strip() + "] = val; // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.")
-        print("  return ::boost::pfr::detail::make_tuple_of_references(" + indexes.strip() + ");")
+        print("  auto& [" + indexes.strip() + "] = const_cast<std::remove_cv_t<T>&>(val); // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.")
     else:
         print("  auto& [")
         print(indexes)
-        print("  ] = val; // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.")
-        print("")
+        print("  ] = const_cast<std::remove_cv_t<T>&>(val); // ====================> Boost.PFR: User-provided type is not a SimpleAggregate.")
+        empty_printer.print_once()
+ 
+    if indexes_count < WORKAROUND_CAST_EXPRESSIONS_LIMIT_PER_LINE:
+        print("  return ::boost::pfr::detail::make_tuple_of_references(" + printed_casts + ");")
+    else:
+        empty_printer.print_once()
         print("  return ::boost::pfr::detail::make_tuple_of_references(")
-        print(indexes)
+        print("    " + printed_casts)
         print("  );")
 
     print("}\n")

test/Jamfile

@@ -0,0 +1,9 @@
+#  Copyright (C) 2023 Denis Mikhailov
+#
+# Use, modification and distribution is subject to 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)
+#
+
+build-project config ;
+build-project core ;

test/appveyor.yml

@@ -32,6 +32,10 @@ skip_tags: true
 
 environment:
   matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      TOOLSET: msvc-9.0
+      ADDRMD: 32
+      CXXSTD: latest # fake
 #    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
 #      TOOLSET: msvc # TODO: clang-win ???
 #      ADDRMD: 32,64

test/config/Jamfile.v2

@@ -0,0 +1,22 @@
+#  Copyright (C) 2023 Denis Mikhailov
+#
+# Use, modification and distribution is subject to 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)
+#
+
+import python ;
+import testing ;
+import ../../config/checks/config : requires ;
+
+project
+    : source-location .
+    : requirements
+        <define>BOOST_PFR_DETAIL_STRICT_RVALUE_TESTING=1
+    ;
+
+
+test-suite pfr_tests
+  :
+    [ run print_config.cpp : : : <test-info>always_show_run_output : auto_engine_config ]
+  ;

test/config/print_config.cpp

@@ -1,9 +1,9 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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)
 
-#include <boost/pfr/core.hpp>
+#include <boost/pfr/config.hpp> // inclusion of an another PFR header may fail when BOOST_PFR_ENABLED=0
 
 #include <iostream>
 
@@ -13,6 +13,8 @@ int main() {
         << "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'
+        << "BOOST_PFR_ENABLE_IMPLICIT_REFLECTION == " << BOOST_PFR_ENABLE_IMPLICIT_REFLECTION << '\n'
+        << "BOOST_PFR_ENABLED == " << BOOST_PFR_ENABLED << '\n'
         << "__cplusplus == " << __cplusplus << '\n'
 #ifdef __cpp_structured_bindings
         << "__cpp_structured_bindings == " << __cpp_structured_bindings << '\n'

test/core/Jamfile.v2

@@ -1,4 +1,4 @@
-#  Copyright (C) 2016-2021 Antony Polukhin.
+#  Copyright (C) 2016-2023 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
@@ -40,7 +40,7 @@ explicit compiler_supports_loophole ;
 
 local DISABLE_ON_MSVC = ; #<toolset>msvc:<build>no ;
 local REQUIRE_LOOPHOLE =
-    [ check-target-builds ../test//compiler_supports_loophole : : <build>no ]
+    [ check-target-builds ../core//compiler_supports_loophole : : <build>no ]
   ;
 
 local STRUCTURED_BINDING_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CPP17=1 [ requires cxx17_structured_bindings ] ;
@@ -49,10 +49,10 @@ local CLASSIC_ENGINE = <define>BOOST_PFR_USE_LOOPHOLE=0 <define>BOOST_PFR_USE_CP
 
 test-suite pfr_tests
   :
-    [ run print_config.cpp : : : <test-info>always_show_run_output : auto_engine_config ]
-
     [ run offset_based_getter.cpp ]
 
+    [ run can_be_as_fallback_in_the_fusion.cpp ]
+
     [ run test_tuple_sizes_on.cpp : : : <define>BOOST_PFR_RUN_TEST_ON=char : test_tuple_sizes_on_chars ]
     [ run test_tuple_sizes_on.cpp : : : <define>BOOST_PFR_RUN_TEST_ON=int : test_tuple_sizes_on_ints ]
     [ run test_tuple_sizes_on.cpp : : : <define>BOOST_PFR_RUN_TEST_ON=short : test_tuple_sizes_on_shorts ]
@@ -60,9 +60,9 @@ test-suite pfr_tests
     [ run test_tuple_sizes_on.cpp : : : <define>BOOST_PFR_RUN_TEST_ON="std::size_t" : test_tuple_sizes_on_size_ts ]
 
     [ run run/motivating_example.cpp      : : : : auto_engine_motivating ]
-    [ run ../example/sample_printing.cpp  : : : : auto_engine_sample_printing ]
-    [ run ../example/get.cpp              : : : : auto_engine_get ]
-    [ run ../example/quick_examples.cpp   : : : : auto_engine_quick ]
+    [ run ../../example/sample_printing.cpp  : : : : auto_engine_sample_printing ]
+    [ run ../../example/get.cpp              : : : : auto_engine_get ]
+    [ run ../../example/quick_examples.cpp   : : : : auto_engine_quick ]
   ;
 
 local BLACKLIST_TESTS_FOR_LOOPHOLE =
@@ -95,7 +95,7 @@ local BLACKLIST_TESTS_FOR_CLASSIC =
     tie_anonymous_const_field
   ;
 
-for local source_file in [ glob ./run/*.cpp ] [ glob ../example/*.cpp ]
+for local source_file in [ glob ./run/*.cpp ] [ glob ../../example/*.cpp ]
 {
     local target_name = $(source_file[1]:B) ;
     pfr_tests += [ run $(source_file) : : : $(STRUCTURED_BINDING_ENGINE) : $(target_name)_sb ] ;
@@ -129,5 +129,5 @@ for local source_file in [ glob ./compile-fail/*.cpp ]
 
 if [ python.configured ]
 {
-    testing.make-test run-pyd : ../misc/generate_cpp17.py ;
+    testing.make-test run-pyd : ../../misc/generate_cpp17.py ;
 }

test/core/can_be_as_fallback_in_the_fusion.cpp

@@ -0,0 +1,37 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#include <type_traits>
+
+struct Aggregate {};
+using NonAggregate = int;
+
+template<class T>
+struct is_implicitly_reflectable : std::false_type
+{};
+
+template<>
+struct is_implicitly_reflectable<Aggregate> : std::true_type
+{};
+
+template<class T, class E=void>
+struct tag_of_fallback {
+    using type = int; // unknown
+};
+
+template<class T>
+struct tag_of_fallback<T, std::enable_if_t<std::is_same<T,T>::value>>
+{
+    using type = std::conditional_t<
+        is_implicitly_reflectable<T>::value
+      , std::true_type
+      , std::false_type
+    >;
+};
+
+static_assert(tag_of_fallback<Aggregate>::type::value == true, "");
+static_assert(tag_of_fallback<NonAggregate>::type::value == false, "");
+
+int main() { }

test/core/compile-fail/boost_pfr_disabled_via_macro.cpp

@@ -0,0 +1,10 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#define BOOST_PFR_ENABLED 0
+#include <boost/pfr/core.hpp>
+
+int main() { }
+

test/core/compile-fail/fields_count_on_reference.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/movable_and_lvalue_references.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/non_aggregate.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/compile-fail/ops_on_union.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/ops_unions.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/ops_unrestricted_unions.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/pfr_review_test2.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 Antony Polukhin
 // Copyright (c) 2020 Richard Hodges
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying

test/core/compile-fail/private_fields.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/protected_fields.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/compile-fail/rvalue_tie.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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/core/compile-fail/virtual_functions.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/loophole_detection.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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/core/offset_based_getter.cpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2019 Ilya Kiselev
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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/core/run/bitfields_count.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/constexpr_ops.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/core17_generated.cpp

@@ -0,0 +1,125 @@
+// Copyright (c) 2023 Denis Mikhailov
+//
+// 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)
+
+#include <boost/pfr/core.hpp>
+#include <type_traits> // for std::is_same
+
+struct A {
+    const volatile int cv_value = 0;
+    volatile int v_value = 0;
+    const int c_value = 0;
+    int value = 0;
+
+    const volatile int& cv_ref;
+    volatile int& v_ref;
+    const int& c_ref;
+    int& ref;
+
+    const volatile int&& cv_rref;
+    volatile int&& v_rref;
+    const int&& c_rref;
+    int&& rref;
+};
+
+int main() {
+#if BOOST_PFR_USE_CPP17
+    const volatile int cv_value = 0;
+    volatile int v_value = 0;
+    const int c_value = 0;
+    int value = 0;
+
+    typedef boost::pfr::detail::size_t_<12> fields_count_tag;
+
+    {
+        A a {cv_value, v_value, c_value, value,
+             cv_value, v_value, c_value, value,
+             std::move(cv_value), std::move(v_value), std::move(c_value), std::move(value)};
+
+        const auto t = boost::pfr::detail::tie_as_tuple(a, fields_count_tag{});
+
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<0>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<1>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<2>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<3>(t)), int&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<4>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<5>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<6>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<7>(t)), int&>());
+        // FIXME implement rvalue references as a field support
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<8>(t)), int const volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<9>(t)), int volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<10>(t)), int const&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<11>(t)), int&&>());
+    }
+
+    {
+        const A a {cv_value, v_value, c_value, value,
+                   cv_value, v_value, c_value, value,
+                   std::move(cv_value), std::move(v_value), std::move(c_value), std::move(value)};
+
+        const auto t = boost::pfr::detail::tie_as_tuple(a, fields_count_tag{});
+
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<0>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<1>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<2>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<3>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<4>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<5>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<6>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<7>(t)), int&>());
+        // FIXME implement rvalue references as a field support
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<8>(t)), int const volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<9>(t)), int volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<10>(t)), int const&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<11>(t)), int&&>());
+    }
+
+    {
+        volatile A a {cv_value, v_value, c_value, value,
+                      cv_value, v_value, c_value, value,
+                      std::move(cv_value), std::move(v_value), std::move(c_value), std::move(value)};
+
+        const auto t = boost::pfr::detail::tie_as_tuple(a, fields_count_tag{});
+
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<0>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<1>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<2>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<3>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<4>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<5>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<6>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<7>(t)), int&>());
+        // FIXME implement rvalue references as a field support
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<8>(t)), int const volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<9>(t)), int volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<10>(t)), int const&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<11>(t)), int&&>());
+    }
+
+    {
+        const volatile A a {cv_value, v_value, c_value, value,
+                            cv_value, v_value, c_value, value,
+                            std::move(cv_value), std::move(v_value), std::move(c_value), std::move(value)};
+
+        const auto t = boost::pfr::detail::tie_as_tuple(a, fields_count_tag{});
+
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<0>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<1>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<2>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<3>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<4>(t)), int const volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<5>(t)), int volatile&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<6>(t)), int const&>());
+        static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<7>(t)), int&>());
+        // FIXME implement rvalue references as a field support
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<8>(t)), int const volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<9>(t)), int volatile&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<10>(t)), int const&&>());
+        // static_assert(std::is_same<decltype(boost::pfr::detail::sequence_tuple::get<11>(t)), int&&>());
+    }
+
+#endif
+}
+

test/core/run/destructuring_tie.cpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2018 Adam Butcher, Antony Polukhin
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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/core/run/error_pfr_c1202.cpp

@@ -1,9 +1,9 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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)
 
-// Example from https://github.com/apolukhin/magic_get/issues/21
+// Example from https://github.com/boostorg/pfr/issues/21
 
 
 // boost::pfr::for_each_field crashes when sizeof(MyConfig) > 248 (probably >= 256)

test/core/run/fields_count_on_const.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/for_each_field.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/functions_for.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/get_by_type.cpp

@@ -0,0 +1,67 @@
+// Copyright (c) 2020-2023 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)
+
+
+#include <boost/pfr/core.hpp>
+
+#include <boost/core/lightweight_test.hpp>
+
+namespace testing {
+
+namespace {
+
+struct Aggregate {
+    int a;
+    const int b;
+    double c;
+    double d;
+    short e;
+};
+
+void test_get_by_type() {
+#if BOOST_PFR_USE_CPP17
+    Aggregate t{1, 2, 3.4, 5.6, 7};
+
+    BOOST_TEST_EQ(boost::pfr::get<int>(t), 1);
+    BOOST_TEST_EQ(boost::pfr::get<const int>(t), 2);
+    BOOST_TEST_EQ(boost::pfr::get<short>(t), 7);
+
+    boost::pfr::get<int>(t) = 11;
+    boost::pfr::get<short>(t) = 77;
+#endif
+}
+
+void test_const_get_by_type() {
+#if BOOST_PFR_USE_CPP17 || BOOST_PFR_USE_LOOPHOLE
+    const Aggregate t{1, 2, 3.4, 5.6, 7};
+    BOOST_TEST_EQ(boost::pfr::get<short>(t), 7);
+#endif
+}
+
+void test_get_by_type_pod() {
+    struct PodAggregate {
+      int i;
+      short s;
+    };
+
+    PodAggregate pod{1, 2};
+    BOOST_TEST_EQ(boost::pfr::get<int>(pod), 1);
+    BOOST_TEST_EQ(boost::pfr::get<short>(pod), 2);
+}
+
+} // anonymous namespace
+
+
+} // namespace testing
+
+int main() {
+    testing::test_get_by_type();
+    testing::test_const_get_by_type();
+    testing::test_get_by_type_pod();
+
+    return boost::report_errors();
+}
+
+

test/core/run/get_const_field.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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/core/run/get_rvalue.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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/core/run/is_implicitly_reflectable.cpp

@@ -0,0 +1,83 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#include <iostream>
+#include <boost/pfr/traits.hpp>
+#include <type_traits>  // for std::true_type, std::false_type and std::is_aggregate
+
+namespace boost { namespace pfr {
+    struct boost_fusion_tag;
+    struct boost_json_tag;
+}}
+
+struct Aggregate {};
+using Nonaggregate = int;
+
+#if defined(__cpp_lib_is_aggregate)
+static_assert(std::is_aggregate<Aggregate>::value && !std::is_aggregate<Nonaggregate>::value, "");
+#endif
+
+using Reflectable = short;
+struct Nonrefrectable {};
+
+using ReflectableBoostFusion = short;
+struct NonrefrectableBoostFusion {};
+
+using ReflectableBoostJson = short;
+struct NonrefrectableBoostJson {};
+
+namespace boost { namespace pfr {
+    template<class All> struct is_reflectable<Reflectable, All> : std::true_type {};
+    template<class All> struct is_reflectable<Nonrefrectable, All> : std::false_type {};
+    template<> struct is_reflectable<ReflectableBoostFusion, boost_fusion_tag> : std::true_type {};
+    template<> struct is_reflectable<NonrefrectableBoostFusion, boost_fusion_tag> : std::false_type {};
+    template<> struct is_reflectable<ReflectableBoostJson, boost_json_tag> : std::true_type {};
+    template<> struct is_reflectable<NonrefrectableBoostJson, boost_json_tag> : std::false_type {};
+}}
+
+
+#if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+template<class T, class Tag>
+void assert_reflectable() {
+    static_assert(boost::pfr::is_implicitly_reflectable_v<T, Tag>, "");
+    static_assert(boost::pfr::is_implicitly_reflectable_v<const T, Tag>, "");
+    static_assert(boost::pfr::is_implicitly_reflectable_v<volatile T, Tag>, "");
+    static_assert(boost::pfr::is_implicitly_reflectable_v<const volatile T, Tag>, "");
+}
+
+template<class T, class Tag>
+void assert_non_reflectable() {
+    static_assert(!boost::pfr::is_implicitly_reflectable_v<T, Tag>, "");
+    static_assert(!boost::pfr::is_implicitly_reflectable_v<const T, Tag>, "");
+    static_assert(!boost::pfr::is_implicitly_reflectable_v<volatile T, Tag>, "");
+    static_assert(!boost::pfr::is_implicitly_reflectable_v<const volatile T, Tag>, "");
+}
+#endif  // #if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+
+int main() {
+#if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+    std::cout << "Implicit reflection is available in this platform.." << std::endl;
+    {
+        using tag = boost::pfr::boost_json_tag;
+        assert_reflectable<Aggregate, tag>();
+        assert_non_reflectable<Nonaggregate, tag>();
+        assert_reflectable<Reflectable, tag>();
+        assert_non_reflectable<Nonrefrectable, tag>();
+        assert_reflectable<ReflectableBoostJson, tag>();
+        assert_non_reflectable<NonrefrectableBoostJson, tag>();
+    }
+
+    {
+        using tag = boost::pfr::boost_fusion_tag;
+        assert_reflectable<Aggregate, tag>();
+        assert_non_reflectable<Nonaggregate, tag>();
+        assert_reflectable<Reflectable, tag>();
+        assert_non_reflectable<Nonrefrectable, tag>();
+        assert_reflectable<ReflectableBoostFusion, tag>();
+        assert_non_reflectable<NonrefrectableBoostFusion, tag>();
+    }
+#endif  // #if BOOST_PFR_ENABLE_IMPLICIT_REFLECTION
+}
+

test/core/run/is_reflectable.cpp

@@ -0,0 +1,112 @@
+// Copyright (c) 2022 Denis Mikhailov
+//
+// 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)
+
+#include <boost/pfr/traits.hpp>
+#include <type_traits>  // for std::true_type, std::false_type
+
+namespace boost { namespace pfr {
+    struct boost_fusion_tag;
+    struct boost_json_tag;
+}}
+
+struct Reflectable {};
+struct Nonrefrectable {};
+struct Unknown {};
+
+struct ReflectableBoostFusion {};
+struct NonrefrectableBoostFusion {};
+
+struct ReflectableBoostJson {};
+struct NonrefrectableBoostJson {};
+
+namespace boost { namespace pfr {
+    template<class All> struct is_reflectable<Reflectable, All> : std::true_type {};
+    template<class All> struct is_reflectable<Nonrefrectable, All> : std::false_type {};
+    template<> struct is_reflectable<ReflectableBoostFusion, boost_fusion_tag> : std::true_type {};
+    template<> struct is_reflectable<NonrefrectableBoostFusion, boost_fusion_tag> : std::false_type {};
+    template<> struct is_reflectable<ReflectableBoostJson, boost_json_tag> : std::true_type {};
+    template<> struct is_reflectable<NonrefrectableBoostJson, boost_json_tag> : std::false_type {};
+}}
+
+
+
+
+namespace helpers {
+template <class T, class Tag>
+constexpr decltype(boost::pfr::is_reflectable<T, Tag>::value) is_reflectability_known(long) {
+    return true;
+}
+
+template <class T, class Tag>
+constexpr bool is_reflectability_known(int) {
+    return false;
+}
+}
+
+template<class T, class Tag>
+void assert_reflectable_impl() {
+    static_assert(helpers::is_reflectability_known<T, Tag>(1L), "");
+    static_assert(boost::pfr::is_reflectable<T, Tag>::value, "");
+}
+
+template<class T, class Tag>
+void assert_non_reflectable_impl() {
+    static_assert(helpers::is_reflectability_known<T, Tag>(1L), "");
+    static_assert(!boost::pfr::is_reflectable<T, Tag>::value, "");
+}
+
+template<class T, class Tag>
+void assert_unknown_impl() {
+    static_assert(!helpers::is_reflectability_known<T, Tag>(1L), "");
+}
+
+template<class T, class Tag>
+void assert_reflectable() {
+    assert_reflectable_impl<T, Tag>();
+    assert_reflectable_impl<const T, Tag>();
+    assert_reflectable_impl<volatile T, Tag>();
+    assert_reflectable_impl<const volatile T, Tag>();
+}
+
+template<class T, class Tag>
+void assert_non_reflectable() {
+    assert_non_reflectable_impl<T, Tag>();
+    assert_non_reflectable_impl<const T, Tag>();
+    assert_non_reflectable_impl<volatile T, Tag>();
+    assert_non_reflectable_impl<const volatile T, Tag>();
+}
+
+template<class T, class Tag>
+void assert_unknown() {
+    assert_unknown_impl<T, Tag>();
+    assert_unknown_impl<const T, Tag>();
+    assert_unknown_impl<volatile T, Tag>();
+    assert_unknown_impl<const volatile T, Tag>();
+}
+
+int main() {
+    {
+        using tag = boost::pfr::boost_json_tag;
+        assert_reflectable<Reflectable, tag>();
+        assert_non_reflectable<Nonrefrectable, tag>();
+        assert_unknown<Unknown, tag>();
+        assert_unknown<ReflectableBoostFusion, tag>();
+        assert_unknown<NonrefrectableBoostFusion, tag>();
+        assert_reflectable<ReflectableBoostJson, tag>();
+        assert_non_reflectable<NonrefrectableBoostJson, tag>();
+    }
+
+    {
+        using tag = boost::pfr::boost_fusion_tag;
+        assert_reflectable<Reflectable, tag>();
+        assert_non_reflectable<Nonrefrectable, tag>();
+        assert_unknown<Unknown, tag>();
+        assert_reflectable<ReflectableBoostFusion, tag>();
+        assert_non_reflectable<NonrefrectableBoostFusion, tag>();
+        assert_unknown<ReflectableBoostJson, tag>();
+        assert_unknown<NonrefrectableBoostJson, tag>();
+    }
+}
+

test/core/run/issue30.cpp

@@ -1,9 +1,9 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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 case for https://github.com/apolukhin/magic_get/issues/30
+// Test case for https://github.com/boostorg/pfr/issues/30
 
 #include <memory>
 #include <boost/pfr.hpp>

test/core/run/issue33.cpp

@@ -1,11 +1,12 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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 case for https://github.com/apolukhin/magic_get/issues/33
+// Test case for https://github.com/boostorg/pfr/issues/33
 
 #include <iostream>
+#include <memory>
 #include <vector>
 #include <boost/pfr.hpp>
 #include <boost/core/lightweight_test.hpp>

test/core/run/motivating_example.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/motivating_example2.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/non_copyable_but_movable.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/non_dc_non_cop_but_mov.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/non_default_constructible.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/non_movable.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/non_std_layout.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2021 Antony Polukhin
+// Copyright (c) 2018-2023 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/core/run/ops.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/optional_chrono.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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/core/run/read_write.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/read_write_non_literal.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/std_interactions.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2021 Antony Polukhin
+// Copyright (c) 2016-2023 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/core/run/template_constructor.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2021 Antony Polukhin.
+// Copyright (c) 2019-2023 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/core/run/template_forwarding_ref.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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/core/run/template_unconstrained.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2019-2021 Antony Polukhin
+// Copyright (c) 2019-2023 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/core/run/tie_anonymous.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Antony Polukhin
+// Copyright (c) 2020-2023 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)