From 346dc03746d71ac7223cc1d150df877b7843a4f7 Mon Sep 17 00:00:00 2001
From: Andrzej Krzemienski <akrzemi1@gmail.com>
Date: Thu, 15 Aug 2024 11:42:42 +0200
Subject: [PATCH] Reimplement trivially semiregular trait

---
 .../optional/detail/experimental_traits.hpp   | 23 +-----
 include/boost/optional/optional.hpp           |  4 --
 test/optional_test_experimental_traits.cpp    | 70 +++++++++----------
 test/optional_test_static_properties.cpp      | 56 +++++++--------
 4 files changed, 65 insertions(+), 88 deletions(-)

diff --git a/include/boost/optional/detail/experimental_traits.hpp b/include/boost/optional/detail/experimental_traits.hpp
index 3776551..4d4abe8 100644
--- a/include/boost/optional/detail/experimental_traits.hpp
+++ b/include/boost/optional/detail/experimental_traits.hpp
@@ -12,8 +12,6 @@
 #ifndef BOOST_OPTIONAL_DETAIL_EXPERIMENTAL_TRAITS_04NOV2017_HPP
 #define BOOST_OPTIONAL_DETAIL_EXPERIMENTAL_TRAITS_04NOV2017_HPP
 
-#include <boost/config.hpp>
-#include <boost/config/workaround.hpp>
 #include <boost/type_traits.hpp>
 
 // The condition to use POD implementation
@@ -22,8 +20,6 @@
 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
 #elif defined BOOST_OPTIONAL_CONFIG_NO_SPEC_FOR_TRIVIAL_TYPES
 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-#elif !defined BOOST_HAS_TRIVIAL_CONSTRUCTOR
-# define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
 #elif !defined BOOST_HAS_TRIVIAL_MOVE_ASSIGN
 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
 #elif !defined BOOST_HAS_TRIVIAL_MOVE_CONSTRUCTOR
@@ -34,21 +30,6 @@
 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
 #elif !defined BOOST_HAS_TRIVIAL_DESTRUCTOR
 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-#elif BOOST_WORKAROUND(BOOST_GCC, < 50000)
-# define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-#endif
-
-// GCC 5 or higher, or clang with libc++ or clang with libstdc++ 5 or higher
-#if __cplusplus >= 201103L
-#  if BOOST_WORKAROUND(BOOST_GCC, >= 50000)
-#    define BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
-#  elif (defined BOOST_CLANG)
-#    if BOOST_LIB_STD_CXX > 0
-#      define BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
-#    elif BOOST_LIB_STD_GNU >= 441200023 && BOOST_LIB_STD_GNU != 450600023 && BOOST_LIB_STD_GNU != 450600026 && BOOST_LIB_STD_GNU != 460800003 && BOOST_LIB_STD_GNU != 450400026 && BOOST_LIB_STD_GNU != 460700026
-#      define BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
-#    endif
-#  endif
 #endif
 
 
@@ -56,7 +37,7 @@ namespace boost { namespace optional_detail {
 
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
 template <typename T>
-struct is_type_trivially_copyable
+struct is_trivially_semiregular
   : boost::conditional<(boost::has_trivial_copy_constructor<T>::value &&
                         boost::has_trivial_move_constructor<T>::value &&
                         boost::has_trivial_destructor<T>::value &&
@@ -66,7 +47,7 @@ struct is_type_trivially_copyable
 {};
 #else
 template <typename T>
-struct is_type_trivially_copyable
+struct is_trivially_semiregular
 : boost::conditional<(boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value),
                      boost::true_type, boost::false_type>::type
 {};
diff --git a/include/boost/optional/optional.hpp b/include/boost/optional/optional.hpp
index 72fbd60..393eb43 100644
--- a/include/boost/optional/optional.hpp
+++ b/include/boost/optional/optional.hpp
@@ -22,10 +22,6 @@
 #include <iosfwd>
 #endif // BOOST_NO_IOSTREAM
 
-#ifdef BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
-#  include <type_traits>
-#endif
-
 #include <boost/assert.hpp>
 #include <boost/core/addressof.hpp>
 #include <boost/core/enable_if.hpp>
diff --git a/test/optional_test_experimental_traits.cpp b/test/optional_test_experimental_traits.cpp
index 5088b4a..eb8a736 100644
--- a/test/optional_test_experimental_traits.cpp
+++ b/test/optional_test_experimental_traits.cpp
@@ -43,9 +43,9 @@ struct DeletedDefault
 };
 
 namespace boost { namespace optional_config {
-  
+
 template <> struct optional_uses_direct_storage_for<CustomizedTrivial> : boost::true_type {};
-  
+
 }}
 
 struct CustDtor
@@ -78,47 +78,47 @@ void test_type_traits()
   // this only tests if type traits are implemented correctly
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<int> ));
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<double> ));
-  
+
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<CustomizedTrivial> ));
-  
+
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<PrivDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<NoDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, CustDefault> > ));
-  
+
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustDtor> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustAssign> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustMove> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, CustMove> > ));
-  
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<int> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<double> ));
 
- 
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<int> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<double> ));
+
+
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<Empty> ));
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, double> > ));
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<Aggregate<Empty, int>, double> > ));
-  
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Empty> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, double> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<Aggregate<Empty, int>, double> > ));
-  
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<PrivDefault> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<NoDefault> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<CustDefault> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, CustDefault> > )); 
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<DeletedDefault> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, DeletedDefault> > ));
-#endif  
+
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Empty> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, double> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<Aggregate<Empty, int>, double> > ));
+
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<PrivDefault> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<NoDefault> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<CustDefault> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, CustDefault> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<DeletedDefault> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, DeletedDefault> > ));
+#endif
 
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<DeletedDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, DeletedDefault> > ));
-  
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustDtor> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustAssign> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustMove> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, CustMove> > ));
+
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustDtor> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustAssign> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustMove> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, CustMove> > ));
 }
 
 void test_trivial_copyability()
@@ -127,16 +127,16 @@ void test_trivial_copyability()
   BOOST_TEST_TRAIT_TRUE((boost::is_base_of<boost::optional_detail::tc_optional_base<double>, boost::optional<double> > ));
   BOOST_TEST_TRAIT_TRUE((boost::is_base_of<boost::optional_detail::tc_optional_base<CustomizedTrivial>, boost::optional<CustomizedTrivial> > ));
   BOOST_TEST_TRAIT_FALSE((boost::is_base_of<boost::optional_detail::tc_optional_base<DeletedDefault>, boost::optional<DeletedDefault> > ));
-  
+
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<int> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<double> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<CustomizedTrivial> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Empty> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Aggregate<int, double> > > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Aggregate<Aggregate<Empty, int>, double> > > ));
-  
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<DeletedDefault> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<int> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<double> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<CustomizedTrivial> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Empty> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Aggregate<int, double> > > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Aggregate<Aggregate<Empty, int>, double> > > ));
+
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<boost::optional<DeletedDefault> > ));
 #endif
 }
 
diff --git a/test/optional_test_static_properties.cpp b/test/optional_test_static_properties.cpp
index 5dc1053..90cd643 100644
--- a/test/optional_test_static_properties.cpp
+++ b/test/optional_test_static_properties.cpp
@@ -43,9 +43,9 @@ struct DeletedDefault
 };
 
 namespace boost { namespace optional_config {
-  
+
 template <> struct optional_uses_direct_storage_for<CustomizedTrivial> : boost::true_type {};
-  
+
 }}
 
 struct CustDtor
@@ -78,40 +78,40 @@ void test_type_traits()
   // this only tests if type traits are implemented correctly
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<int> ));
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<double> ));
-  
+
   BOOST_TEST_TRAIT_TRUE(( boost::optional_config::optional_uses_direct_storage_for<CustomizedTrivial> ));
-  
+
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<PrivDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<NoDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, CustDefault> > ));
-  
+
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustDtor> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustAssign> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<CustMove> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, CustMove> > ));
-  
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<int> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<double> ));
+
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<int> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<double> ));
 
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Empty> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, double> > ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<Aggregate<Empty, int>, double> > ));
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-  
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Empty> ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, double> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<Aggregate<Empty, int>, double> > ));
-  
-#endif  
+
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Empty> ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, double> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<Aggregate<Aggregate<Empty, int>, double> > ));
+
+#endif
 
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<DeletedDefault> ));
   BOOST_TEST_TRAIT_FALSE(( boost::optional_config::optional_uses_direct_storage_for<Aggregate<int, DeletedDefault> > ));
-  
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustDtor> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustAssign> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<CustMove> ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<Aggregate<int, CustMove> > ));
+
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustDtor> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustAssign> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<CustMove> ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<Aggregate<int, CustMove> > ));
 }
 
 void test_trivial_copyability()
@@ -120,18 +120,18 @@ void test_trivial_copyability()
   BOOST_TEST_TRAIT_TRUE((boost::is_base_of<boost::optional_detail::tc_optional_base<double>, boost::optional<double> > ));
   BOOST_TEST_TRAIT_TRUE((boost::is_base_of<boost::optional_detail::tc_optional_base<CustomizedTrivial>, boost::optional<CustomizedTrivial> > ));
   BOOST_TEST_TRAIT_FALSE((boost::is_base_of<boost::optional_detail::tc_optional_base<DeletedDefault>, boost::optional<DeletedDefault> > ));
-  
+
 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<int> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<double> > ));
-  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<CustomizedTrivial> > ));
-  
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<DeletedDefault> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<int> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<double> > ));
+  BOOST_TEST_TRAIT_TRUE(( boost::optional_detail::is_trivially_semiregular<boost::optional<CustomizedTrivial> > ));
+
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<boost::optional<DeletedDefault> > ));
 #endif
 
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Empty> > ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Aggregate<int, double> > > ));
-  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_type_trivially_copyable<boost::optional<Aggregate<Aggregate<Empty, int>, double> > > ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Empty> > ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Aggregate<int, double> > > ));
+  BOOST_TEST_TRAIT_FALSE(( boost::optional_detail::is_trivially_semiregular<boost::optional<Aggregate<Aggregate<Empty, int>, double> > > ));
 }
 
 #endif