Implement C++17 variable templates for type traits.

	* include/std/chrono (treat_as_floating_point_v): New.
	* include/std/ratio (ratio_equal_v, ratio_not_equal_v)
	(ratio_less_v, ratio_less_equal_v, ratio_greater_v)
	(ratio_greater_equal_v): Likewise.
	* include/std/system_error (is_error_code_enum_v)
	(is_error_condition_enum_v): Likewise.
	* include/std/tuple (tuple_size_v): Likewise.
	* type_traits (conjunction_v, disjunction_v, negation_v)
	(is_void_v, is_null_pointer_v, is_integral_v, is_floating_point_v)
	(is_array_v, is_pointer_v, is_lvalue_reference_v)
	(is_rvalue_reference_v, is_member_object_pointer_v)
	(is_member_function_pointer_v, is_enum_v, is_union_v)
	(is_class_v, is_function_v, is_reference_v, is_arithmetic_v)
	(is_fundamental_v, is_object_v, is_scalar_v, is_compound_v)
	(is_member_pointer_v, is_const_v, is_volatile_v, is_trivial_v)
	(is_trivially_copyable_v, is_standard_layout_v)
	(is_pod_v, is_literal_type_v, is_empty_v, is_polymorphic_v)
	(is_abstract_v, is_final_v, is_signed_v, is_unsigned_v)
	(is_constructible_v, is_default_constructible_v)
	(is_copy_constructible_v, is_move_constructible_v)
	(is_assignable_v, is_copy_assignable_v, is_move_assignable_v)
	(is_destructible_v, is_trivially_constructible_v)
	(is_trivially_default_constructible_v)
 	(is_trivially_copy_constructible_v, is_trivially_move_constructible_v)
	(is_trivially_assignable_v, is_trivially_copy_assignable_v)
	(is_trivially_move_assignable_v, is_trivially_destructible_v)
	(is_nothrow_constructible_v, is_nothrow_default_constructible_v)
	(is_nothrow_copy_constructible_v, is_nothrow_move_constructible_v)
	(is_nothrow_assignable_v, is_nothrow_copy_assignable_v)
	(is_nothrow_move_assignable_v, is_nothrow_destructible_v)
	(has_virtual_destructor_v, alignment_of_v, rank_v, extent_v)
	(is_same_v, is_base_of_v, is_convertible_v): Likewise.
	* testsuite/19_diagnostics/error_code/is_error_code_v.cc: Likewise.
	* testsuite/20_util/duration/requirements/treat_as_floating_point_v.cc:
	Likewise.
	* testsuite/20_util/ratio/requirements/ratio_equal_v.cc: Likewise.
	* testsuite/20_util/tuple/tuple_size_v.cc: Likewise.
	* testsuite/20_util/variable_templates_for_traits.cc: Likewise.

From-SVN: r238892

libstdc++-v3/ChangeLog

+2016-07-29  Ville Voutilainen  <ville.voutilainen@gmail.com>
+
+	Implement C++17 variable templates for type traits.
+	* include/std/chrono (treat_as_floating_point_v): New.
+	* include/std/ratio (ratio_equal_v, ratio_not_equal_v)
+	(ratio_less_v, ratio_less_equal_v, ratio_greater_v)
+	(ratio_greater_equal_v): Likewise.
+	* include/std/system_error (is_error_code_enum_v)
+	(is_error_condition_enum_v): Likewise.
+	* include/std/tuple (tuple_size_v): Likewise.
+	* type_traits (conjunction_v, disjunction_v, negation_v)
+	(is_void_v, is_null_pointer_v, is_integral_v, is_floating_point_v)
+	(is_array_v, is_pointer_v, is_lvalue_reference_v)
+	(is_rvalue_reference_v, is_member_object_pointer_v)
+	(is_member_function_pointer_v, is_enum_v, is_union_v)
+	(is_class_v, is_function_v, is_reference_v, is_arithmetic_v)
+	(is_fundamental_v, is_object_v, is_scalar_v, is_compound_v)
+	(is_member_pointer_v, is_const_v, is_volatile_v, is_trivial_v)
+	(is_trivially_copyable_v, is_standard_layout_v)
+	(is_pod_v, is_literal_type_v, is_empty_v, is_polymorphic_v)
+	(is_abstract_v, is_final_v, is_signed_v, is_unsigned_v)
+	(is_constructible_v, is_default_constructible_v)
+	(is_copy_constructible_v, is_move_constructible_v)
+	(is_assignable_v, is_copy_assignable_v, is_move_assignable_v)
+	(is_destructible_v, is_trivially_constructible_v)
+	(is_trivially_default_constructible_v)
+ 	(is_trivially_copy_constructible_v, is_trivially_move_constructible_v)
+	(is_trivially_assignable_v, is_trivially_copy_assignable_v)
+	(is_trivially_move_assignable_v, is_trivially_destructible_v)
+	(is_nothrow_constructible_v, is_nothrow_default_constructible_v)
+	(is_nothrow_copy_constructible_v, is_nothrow_move_constructible_v)
+	(is_nothrow_assignable_v, is_nothrow_copy_assignable_v)
+	(is_nothrow_move_assignable_v, is_nothrow_destructible_v)
+	(has_virtual_destructor_v, alignment_of_v, rank_v, extent_v)
+	(is_same_v, is_base_of_v, is_convertible_v): Likewise.
+	* testsuite/19_diagnostics/error_code/is_error_code_v.cc: Likewise.
+	* testsuite/20_util/duration/requirements/treat_as_floating_point_v.cc:
+	Likewise.
+	* testsuite/20_util/ratio/requirements/ratio_equal_v.cc: Likewise.
+	* testsuite/20_util/tuple/tuple_size_v.cc: Likewise.
+	* testsuite/20_util/variable_templates_for_traits.cc: Likewise.
+
 2016-07-29  Andreas Schwab  <schwab@linux-m68k.org>
 
 	* config/abi/post/aarch64-linux-gnu/baseline_symbols.txt: Update.

libstdc++-v3/include/std/chrono

@@ -208,7 +208,11 @@ _GLIBCXX_END_NAMESPACE_VERSION
       struct treat_as_floating_point
       : is_floating_point<_Rep>
       { };
-
+#if __cplusplus > 201402L
+    template <typename _Rep>
+      constexpr bool treat_as_floating_point_v =
+        treat_as_floating_point<_Rep>::value;
+#endif // C++17
     /// duration_values
     template<typename _Rep>
       struct duration_values

libstdc++-v3/include/std/ratio

@@ -401,6 +401,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : integral_constant<bool, !ratio_less<_R1, _R2>::value>
     { };
 
+#if __cplusplus > 201402L
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_equal_v = ratio_equal<_R1, _R2>::value;
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_not_equal_v = ratio_not_equal<_R1, _R2>::value;
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_less_v = ratio_less<_R1, _R2>::value;
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_less_equal_v = ratio_less_equal<_R1, _R2>::value;
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_greater_v = ratio_greater<_R1, _R2>::value;
+  template <typename _R1, typename _R2>
+    constexpr bool ratio_greater_equal_v
+    = ratio_greater_equal<_R1, _R2>::value;
+#endif // C++17
+
   template<typename _R1, typename _R2,
       bool = (_R1::num >= 0),
       bool = (_R2::num >= 0),

libstdc++-v3/include/std/system_error

@@ -60,6 +60,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct is_error_condition_enum<errc>
     : public true_type { };
 
+#if __cplusplus > 201402L
+  template <typename _Tp>
+    constexpr bool is_error_code_enum_v = is_error_code_enum<_Tp>::value;
+  template <typename _Tp>
+    constexpr bool is_error_condition_enum_v =
+      is_error_condition_enum<_Tp>::value;
+#endif // C++17
   inline namespace _V2 {
 
   /// error_category

libstdc++-v3/include/std/tuple

@@ -1265,6 +1265,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct tuple_size<tuple<_Elements...>>
     : public integral_constant<std::size_t, sizeof...(_Elements)> { };
 
+#if __cplusplus > 201402L
+  template <typename _Tp>
+    constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
+#endif
+
   template<std::size_t __i, typename _Head, typename... _Tail>
     constexpr _Head&
     __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept

libstdc++-v3/include/std/type_traits

@@ -172,6 +172,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct negation
     : __not_<_Pp>
     { };
+
+  template<typename... _Bn>
+    constexpr bool conjunction_v
+    = conjunction<_Bn...>::value;
+  
+  template<typename... _Bn>
+    constexpr bool disjunction_v
+    = disjunction<_Bn...>::value;
+  
+  template<typename _Pp>
+    constexpr bool negation_v
+    = negation<_Pp>::value;
+
 #endif
 
   // For several sfinae-friendly trait implementations we transport both the
@@ -2765,6 +2778,159 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr bool is_nothrow_swappable_with_v =
       is_nothrow_swappable_with<_Tp, _Up>::value;
 #endif // __cplusplus >= 201402L
+
+#if __cplusplus > 201402L
+template <typename _Tp>
+  constexpr bool is_void_v = is_void<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_integral_v = is_integral<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_array_v = is_array<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_pointer_v = is_pointer<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_lvalue_reference_v = is_lvalue_reference<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_rvalue_reference_v = is_rvalue_reference<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_member_object_pointer_v =
+    is_member_object_pointer<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_member_function_pointer_v =
+    is_member_function_pointer<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_enum_v = is_enum<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_union_v = is_union<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_class_v = is_class<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_function_v = is_function<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_reference_v = is_reference<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_object_v = is_object<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_scalar_v = is_scalar<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_compound_v = is_compound<_Tp>::value;
+template <typename _Tp>
+ constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_const_v = is_const<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_volatile_v = is_volatile<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivial_v = is_trivial<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_copyable_v = is_trivially_copyable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_pod_v = is_pod<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_empty_v = is_empty<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_abstract_v = is_abstract<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_final_v = is_final<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_signed_v = is_signed<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
+template <typename _Tp, typename... _Args>
+  constexpr bool is_constructible_v = is_constructible<_Tp, _Args...>::value;
+template <typename _Tp>
+  constexpr bool is_default_constructible_v =
+    is_default_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_copy_constructible_v = is_copy_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_move_constructible_v = is_move_constructible<_Tp>::value;
+template <typename _Tp, typename _Up>
+  constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
+template <typename _Tp>
+  constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_destructible_v = is_destructible<_Tp>::value;
+template <typename _Tp, typename... _Args>
+  constexpr bool is_trivially_constructible_v =
+    is_trivially_constructible<_Tp, _Args...>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_default_constructible_v =
+    is_trivially_default_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_copy_constructible_v =
+    is_trivially_copy_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_move_constructible_v =
+    is_trivially_move_constructible<_Tp>::value;
+template <typename _Tp, typename _Up>
+  constexpr bool is_trivially_assignable_v =
+    is_trivially_assignable<_Tp, _Up>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_copy_assignable_v =
+    is_trivially_copy_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_move_assignable_v =
+    is_trivially_move_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_trivially_destructible_v =
+    is_trivially_destructible<_Tp>::value;
+template <typename _Tp, typename... _Args>
+  constexpr bool is_nothrow_constructible_v =
+    is_nothrow_constructible<_Tp, _Args...>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_default_constructible_v =
+    is_nothrow_default_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_copy_constructible_v =
+    is_nothrow_copy_constructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_move_constructible_v =
+    is_nothrow_move_constructible<_Tp>::value;
+template <typename _Tp, typename _Up>
+  constexpr bool is_nothrow_assignable_v =
+    is_nothrow_assignable<_Tp, _Up>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_copy_assignable_v =
+    is_nothrow_copy_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_move_assignable_v =
+    is_nothrow_move_assignable<_Tp>::value;
+template <typename _Tp>
+  constexpr bool is_nothrow_destructible_v =
+    is_nothrow_destructible<_Tp>::value;
+template <typename _Tp>
+  constexpr bool has_virtual_destructor_v =
+    has_virtual_destructor<_Tp>::value;
+template <typename _Tp>
+  constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
+template <typename _Tp>
+  constexpr size_t rank_v = rank<_Tp>::value;
+template <typename _Tp, unsigned _Idx = 0>
+  constexpr size_t extent_v = extent<_Tp, _Idx>::value;
+template <typename _Tp, typename _Up>
+  constexpr bool is_same_v = is_same<_Tp, _Up>::value;
+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;
+#endif // C++17
 #endif
 
 _GLIBCXX_END_NAMESPACE_VERSION

libstdc++-v3/testsuite/19_diagnostics/error_code/is_error_code_v.cc

+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2014-2016 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 moved_to of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <system_error>
+#include <future>
+using namespace std;
+
+// These tests are rather simple, the front-end tests already test
+// variable templates, and the library tests for the underlying
+// traits are more elaborate. These are just simple sanity tests.
+
+static_assert(is_error_code_enum_v<future_errc>
+	      && is_error_code_enum<future_errc>::value, "");
+
+static_assert(!is_error_code_enum_v<int>
+	      && !is_error_code_enum<int>::value, "");
+
+static_assert(is_error_condition_enum_v<errc>
+	      && is_error_condition_enum<errc>::value, "");
+
+static_assert(!is_error_condition_enum_v<int>
+	      && !is_error_condition_enum<int>::value, "");

libstdc++-v3/testsuite/20_util/duration/requirements/treat_as_floating_point_v.cc

+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2014-2016 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 moved_to of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <chrono>
+
+using namespace std::chrono;
+
+// These tests are rather simple, the front-end tests already test
+// variable templates, and the library tests for the underlying
+// traits are more elaborate. These are just simple sanity tests.
+
+static_assert(!treat_as_floating_point_v<int>
+	      && !treat_as_floating_point<int>::value, "");
+
+static_assert(treat_as_floating_point_v<double>
+	      && treat_as_floating_point<double>::value, "");

libstdc++-v3/testsuite/20_util/ratio/requirements/ratio_equal_v.cc

+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2014-2016 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 moved_to of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <ratio>
+
+using namespace std;
+
+// These tests are rather simple, the front-end tests already test
+// variable templates, and the library tests for the underlying
+// traits are more elaborate. These are just simple sanity tests.
+
+static_assert(ratio_equal_v<ratio<1, 3>, ratio<2, 6>>
+	      && ratio_equal<ratio<1, 3>, ratio<2, 6>>::value, "");
+
+static_assert(ratio_not_equal_v<ratio<1, 3>, ratio<2, 5>>
+	      && ratio_not_equal<ratio<1, 3>, ratio<2, 5>>::value, "");
+
+static_assert(ratio_less_v<ratio<1, 4>, ratio<1, 3>>
+	      && ratio_less<ratio<1, 4>, ratio<1, 3>>::value, "");
+
+static_assert(ratio_less_equal_v<ratio<1, 4>, ratio<1, 4>>
+	      && ratio_less_equal_v<ratio<1, 4>, ratio<1, 3>>
+	      && ratio_less_equal<ratio<1, 4>, ratio<1, 4>>::value
+	      && ratio_less_equal<ratio<1, 4>, ratio<1, 3>>::value, "");
+
+static_assert(ratio_greater_v<ratio<1, 3>, ratio<1, 4>>
+	      && ratio_greater<ratio<1, 3>, ratio<1, 4>>::value, "");
+
+static_assert(ratio_greater_equal_v<ratio<1, 4>, ratio<1, 4>>
+	      && ratio_greater_equal_v<ratio<1, 3>, ratio<1, 4>>
+	      && ratio_greater_equal<ratio<1, 4>, ratio<1, 4>>::value
+	      && ratio_greater_equal<ratio<1, 3>, ratio<1, 4>>::value, "");

libstdc++-v3/testsuite/20_util/tuple/tuple_size_v.cc

+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2014-2016 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 moved_to of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <tuple>
+
+using namespace std;
+
+// These tests are rather simple, the front-end tests already test
+// variable templates, and the library tests for the underlying
+// traits are more elaborate. These are just simple sanity tests.
+
+static_assert(tuple_size_v<tuple<int>> == 1
+	      && tuple_size<tuple<int>>::value == 1, "");
+
+static_assert(tuple_size_v<tuple<int, int>> == 2
+	      && tuple_size<tuple<int, int>>::value == 2, "");