fix for cxx14 build

boostorg · Jun 26, 2023 · e8e077c · e8e077c
1 parent 4a1defa
commit e8e077c
Show file tree

Hide file tree

Showing 5 changed files with 137 additions and 67 deletions.
diff --git a/include/boost/pfr/core_name.hpp b/include/boost/pfr/core_name.hpp
@@ -21,28 +21,24 @@
 #include <boost/pfr/detail/make_integer_sequence.hpp>
 
 #include <cstddef>
-#include <string_view>
 
 #include <boost/pfr/tuple_size.hpp>
 
 namespace boost { namespace pfr {
 
 template <std::size_t I, class T>
-constexpr std::string_view get_name() noexcept {
-    static_assert(sizeof(T) && BOOST_PFR_ENABLE_GETTING_NAMES, "====================> Boost.PFR: Calling boost::pfr::get_name is allowed only in C++20");
+constexpr auto get_name() noexcept {
     return detail::sequence_tuple::get<I>( detail::tie_as_names_tuple<T>() );
 }
 
 // FIXME: implement this
 // template<class U, class T>
-// constexpr std::string_view get_name() noexcept {
-//     static_assert(sizeof(T) && BOOST_PFR_ENABLE_GETTING_NAMES, "====================> Boost.PFR: Calling boost::pfr::get_name is allowed only in C++20");
+// constexpr auto get_name() noexcept {
 //     return detail::sequence_tuple::get_by_type_impl<U>( detail::tie_as_names_tuple<T>() );
 // }
 
 template <class T>
 constexpr auto names_as_array() noexcept {
-    static_assert(sizeof(T) && BOOST_PFR_ENABLE_GETTING_NAMES, "====================> Boost.PFR: Calling boost::pfr::names_as_array is allowed only in C++20");
     return detail::make_stdarray_from_tietuple(
 	detail::tie_as_names_tuple<T>(),
 	detail::make_index_sequence< tuple_size_v<T> >()

diff --git a/include/boost/pfr/detail/core_name.hpp b/include/boost/pfr/detail/core_name.hpp
@@ -13,67 +13,17 @@
 #pragma once
 
 #include <boost/pfr/detail/config.hpp>
-#include <boost/pfr/detail/core.hpp>
-#include <boost/pfr/detail/sequence_tuple.hpp>
-#include <boost/pfr/detail/make_integer_sequence.hpp>
-#include <boost/pfr/detail/fields_count.hpp>
-#include <type_traits>
-#include <string_view>
-#include <array>
 
-namespace boost { namespace pfr { namespace detail {
-
-// TODO: move it outside
-template <class... Args>
-constexpr auto make_sequence_tuple(Args... args) noexcept {
-    return sequence_tuple::tuple<Args...>{ args... };
-}
-
-template <auto& ptr> 
-constexpr auto name_of_field_impl() noexcept {
-#ifdef _MSC_VER
-    constexpr std::string_view sv = __FUNCSIG__;
-    constexpr auto last = sv.find_last_not_of(" >(", sv.size() - 6);
+// Each core_name provides `TODO:` and
+// `TODO:` functions.
+//
+// The whole functional of extracting field's names is build on top of those
+// two functions.
+#if BOOST_PFR_ENABLE_GETTING_NAMES
+#include <boost/pfr/detail/core_name20_static.hpp>
 #else
-    constexpr std::string_view sv = __PRETTY_FUNCTION__;
-    constexpr auto last = sv.find_last_not_of(" ])");
+#include <boost/pfr/detail/core_name14_disabled.hpp>
 #endif
-    constexpr auto first = sv.find_last_not_of("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789", last);
-    std::array<char, last - first + 1> res{};
-    auto it = res.data();
-    for (auto a = first+1; a <= last; ++a)
-        *it++ = sv[a];
-    return res;
-}
-
-template <typename T>
-extern const T fake_object;
-
-template <class T, std::size_t I>
-constexpr auto stored_name_of_field = name_of_field_impl<detail::sequence_tuple::get<I>(
-    detail::tie_as_tuple(fake_object<T>) 
-)>();
-
-template <class T, std::size_t... I>
-constexpr auto tie_as_names_tuple_impl(std::index_sequence<I...>) noexcept {
-    return detail::make_sequence_tuple(std::string_view{stored_name_of_field<T, I>.data()}...);
-}
-
-template <class T>
-constexpr auto tie_as_names_tuple() noexcept {
-    static_assert(
-        !std::is_union<T>::value,
-        "====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."
-    );
-    static_assert(
-        sizeof(T) && BOOST_PFR_USE_CPP17,
-	"====================> Boost.PFR: Extraction of field's names is allowed only when the BOOST_PFR_USE_CPP17 macro enabled."
-    );
-
-    return tie_as_names_tuple_impl<T>(detail::make_index_sequence<detail::fields_count<T>()>{});
-}
-
-}}}
 
 #endif // BOOST_PFR_DETAIL_CORE_NAME_HPP
 
diff --git a/include/boost/pfr/detail/core_name14_disabled.hpp b/include/boost/pfr/detail/core_name14_disabled.hpp
@@ -0,0 +1,40 @@
+// Copyright (c) 2023 Bela Schaum, X-Ryl669, 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)
+
+
+// Initial implementation by Bela Schaum, https://github.com/schaumb
+// The way to make it union and UB free by X-Ryl669, https://github.com/X-Ryl669
+//
+
+#ifndef BOOST_PFR_DETAIL_CORE_NAME14_DISABLED_HPP
+#define BOOST_PFR_DETAIL_CORE_NAME14_DISABLED_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+#include <boost/pfr/detail/sequence_tuple.hpp>
+
+namespace boost { namespace pfr { namespace detail {
+
+// TODO: move it outside
+template <class... Args>
+constexpr auto make_sequence_tuple(Args... args) noexcept {
+    return sequence_tuple::tuple<Args...>{ args... };
+}
+
+
+template <class T>
+constexpr auto tie_as_names_tuple() noexcept {
+    static_assert(
+        sizeof(T) && false,
+	"====================> Boost.PFR: Extraction of field's names is allowed only in C++20"
+    );
+
+    return detail::make_sequence_tuple(); 
+}
+
+}}}
+
+#endif // BOOST_PFR_DETAIL_CORE_NAME14_DISABLED_HPP
+
diff --git a/include/boost/pfr/detail/core_name20_static.hpp b/include/boost/pfr/detail/core_name20_static.hpp
@@ -0,0 +1,79 @@
+// Copyright (c) 2023 Bela Schaum, X-Ryl669, 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)
+
+
+// Initial implementation by Bela Schaum, https://github.com/schaumb
+// The way to make it union and UB free by X-Ryl669, https://github.com/X-Ryl669
+//
+
+#ifndef BOOST_PFR_DETAIL_CORE_NAME20_STATIC_HPP
+#define BOOST_PFR_DETAIL_CORE_NAME20_STATIC_HPP
+#pragma once
+
+#include <boost/pfr/detail/config.hpp>
+#include <boost/pfr/detail/core.hpp>
+#include <boost/pfr/detail/sequence_tuple.hpp>
+#include <boost/pfr/detail/make_integer_sequence.hpp>
+#include <boost/pfr/detail/fields_count.hpp>
+#include <type_traits>
+#include <string_view>
+#include <array>
+
+namespace boost { namespace pfr { namespace detail {
+
+// TODO: move it outside
+template <class... Args>
+constexpr auto make_sequence_tuple(Args... args) noexcept {
+    return sequence_tuple::tuple<Args...>{ args... };
+}
+
+template <auto& ptr> 
+constexpr auto name_of_field_impl() noexcept {
+#ifdef _MSC_VER
+    constexpr std::string_view sv = __FUNCSIG__;
+    constexpr auto last = sv.find_last_not_of(" >(", sv.size() - 6);
+#else
+    constexpr std::string_view sv = __PRETTY_FUNCTION__;
+    constexpr auto last = sv.find_last_not_of(" ])");
+#endif
+    constexpr auto first = sv.find_last_not_of("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789", last);
+    std::array<char, last - first + 1> res{};
+    auto it = res.data();
+    for (auto a = first+1; a <= last; ++a)
+        *it++ = sv[a];
+    return res;
+}
+
+template <typename T>
+extern const T fake_object;
+
+template <class T, std::size_t I>
+constexpr auto stored_name_of_field = name_of_field_impl<detail::sequence_tuple::get<I>(
+    detail::tie_as_tuple(fake_object<T>) 
+)>();
+
+template <class T, std::size_t... I>
+constexpr auto tie_as_names_tuple_impl(std::index_sequence<I...>) noexcept {
+    return detail::make_sequence_tuple(std::string_view{stored_name_of_field<T, I>.data()}...);
+}
+
+template <class T>
+constexpr auto tie_as_names_tuple() noexcept {
+    static_assert(
+        !std::is_union<T>::value,
+        "====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."
+    );
+    static_assert(
+        sizeof(T) && BOOST_PFR_USE_CPP17,
+	"====================> Boost.PFR: Extraction of field's names is allowed only when the BOOST_PFR_USE_CPP17 macro enabled."
+    );
+
+    return tie_as_names_tuple_impl<T>(detail::make_index_sequence<detail::fields_count<T>()>{});
+}
+
+}}}
+
+#endif // BOOST_PFR_DETAIL_CORE_NAME20_STATIC_HPP
+
diff --git a/include/boost/pfr/detail/stdarray.hpp b/include/boost/pfr/detail/stdarray.hpp
@@ -1,4 +1,3 @@
-
 // Copyright (c) 2023 Denis Mikhailov
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -12,16 +11,22 @@
 
 #include <utility> // metaprogramming stuff
 #include <tuple>
+#include <type_traits> // for std::common_type_t
 
 #include <boost/pfr/detail/sequence_tuple.hpp>
 
 namespace boost { namespace pfr { namespace detail {
 
+template <class... Types>
+constexpr auto make_stdarray(const Types&... t) noexcept {
+    return std::array<std::common_type_t<Types...>, sizeof...(Types)>{t...};
+}
+
 template <class T, std::size_t... I>
 constexpr auto make_stdarray_from_tietuple(const T& t, std::index_sequence<I...>) noexcept {
-    return std::array{
+    return make_stdarray(
         boost::pfr::detail::sequence_tuple::get<I>(t)...
-    };
+    );
 }
 
 }}}