Another new C++17 feature, using Jakub's new builtin.
* doc/xml/manual/status_cxx2017.xml: Update status.
* include/std/type_traits (has_unique_object_representations): Define.
* testsuite/20_util/has_unique_object_representations/value.cc: New.
* testsuite/20_util/has_unique_object_representations/requirements/
explicit_instantiation.cc: New.
* testsuite/20_util/has_unique_object_representations/requirements/
typedefs.cc: New.
Tested x86_64-linux, committed to trunk.
commit 79664ebd750fbe597021ce039ac86f503d477e76
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Fri Oct 7 12:59:16 2016 +0100
Implement std::has_unique_object_representations
* doc/xml/manual/status_cxx2017.xml: Update status.
* include/std/type_traits (has_unique_object_representations): Define.
* testsuite/20_util/has_unique_object_representations/value.cc: New.
* testsuite/20_util/has_unique_object_representations/requirements/
explicit_instantiation.cc: New.
* testsuite/20_util/has_unique_object_representations/requirements/
typedefs.cc: New.
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
index 9f47b349..f1d709e 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
@@ -441,14 +441,13 @@ Feature-testing recommendations for C++</link>.
</row>
<row>
- <?dbhtml bgcolor="#C8B0B0" ?>
<entry> has_unique_object_representations </entry>
<entry>
<link xmlns:xlink="http://www.w3.org/1999/xlink";
xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0258r2.html";>
P0258R2
</link>
</entry>
- <entry align="center"> No </entry>
+ <entry align="center"> 7 </entry>
<entry><code> __cpp_lib_has_unique_object_representations >= 201606
</code></entry>
</row>
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index cd0ba99..d402b5b 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -3040,6 +3040,16 @@ template <typename _Base, typename _Derived>
constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
template <typename _From, typename _To>
constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
+
+# define __cpp_lib_has_unique_object_representations 201606
+ /// has_unique_object_representations
+ template<typename _Tp>
+ struct has_unique_object_representations
+ : bool_constant<__has_unique_object_representations(
+ remove_cv_t<remove_all_extents_t<_Tp>>
+ )>
+ { };
+
#endif // C++17
_GLIBCXX_END_NAMESPACE_VERSION
diff --git
a/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/explicit_instantiation.cc
b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/explicit_instantiation.cc
new file mode 100644
index 0000000..29be714
--- /dev/null
+++
b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/explicit_instantiation.cc
@@ -0,0 +1,29 @@
+// { dg-options "-std=gnu++1z" }
+// { dg-do compile { target c++1z } }
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// NB: This file is for testing type_traits with NO OTHER INCLUDES.
+
+#include <type_traits>
+
+namespace std
+{
+ typedef short test_type;
+ template struct has_unique_object_representations<test_type>;
+}
diff --git
a/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/typedefs.cc
b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/typedefs.cc
new file mode 100644
index 0000000..e24a972
--- /dev/null
+++
b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/requirements/typedefs.cc
@@ -0,0 +1,32 @@
+// { dg-options "-std=gnu++1z" }
+// { dg-do compile { target c++1z } }
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// NB: This file is for testing type_traits with NO OTHER INCLUDES.
+
+#include <type_traits>
+
+void test01()
+{
+ // Check for required typedefs
+ typedef std::has_unique_object_representations<int> test_type;
+ static_assert( std::is_same<test_type::value_type, bool>::value );
+ typedef std::integral_constant<bool, test_type{}()> bool_type;
+ static_assert( std::is_same<test_type::type, bool_type>::value );
+}
diff --git
a/libstdc++-v3/testsuite/20_util/has_unique_object_representations/value.cc
b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/value.cc
new file mode 100644
index 0000000..5a77ee5
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/has_unique_object_representations/value.cc
@@ -0,0 +1,110 @@
+// { dg-options "-std=gnu++1z" }
+// { dg-do compile { target c++1z } }
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <type_traits>
+#include <testsuite_tr1.h>
+
+void test01()
+{
+ using std::has_unique_object_representations;
+ using __gnu_test::test_category;
+
+ // Positive tests.
+ static_assert(test_category<has_unique_object_representations,
+ char>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ unsigned char>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ signed char>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ unsigned>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ bool>(true), "");
+
+ enum E : unsigned { };
+ static_assert(test_category<has_unique_object_representations,
+ E>(true), "");
+
+ static_assert(test_category<has_unique_object_representations,
+ unsigned[3]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ unsigned[3][2]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ unsigned[]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ unsigned[][2]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ E[3]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ E[3][2]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ E[]>(true), "");
+ static_assert(test_category<has_unique_object_representations,
+ E[][2]>(true), "");
+
+ struct Padded {
+ char c1;
+ alignas(4) char c2;
+ };
+
+ struct Bitfield {
+ int i : 3;
+ };
+
+ struct Aligned {
+ alignas(4) char c;
+ };
+
+ // Negative tests.
+ static_assert(test_category<has_unique_object_representations,
+ void>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ float>(false), ""); // implementation-defined
+ static_assert(test_category<has_unique_object_representations,
+ Padded>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Padded[2]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Padded[2][1]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Padded[]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Padded[][1]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Bitfield>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Bitfield[2]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Bitfield[2][1]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Bitfield[]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Bitfield[][1]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Aligned>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Aligned[2]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Aligned[2][1]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Aligned[]>(false), "");
+ static_assert(test_category<has_unique_object_representations,
+ Aligned[][1]>(false), "");
+}
