Implement <concepts> header for C++20

There are currently no tests for [concepts.compare], but they will be
added ASAP.

	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/precompiled/stdc++.h: Include <concepts>.
	* include/std/concepts: New header for C++20.
	* include/std/version (__cpp_lib_concepts): Define.
	* scripts/create_testsuite_files: Look for test files in new std
	directory.
	* testsuite/libstdc++-dg/conformance.exp: Likewise.
	* testsuite/std/concepts/concepts.callable/invocable.cc: New test.
	* testsuite/std/concepts/concepts.callable/regular_invocable.cc: New
	test.
	* testsuite/std/concepts/concepts.callable/relation.cc: New test.
	* testsuite/std/concepts/concepts.callable/strictweakorder.cc: New
	test.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/
	floating_point.cc: New test.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/integral.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/
	signed_integral.cc: New test.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/
	unsigned_integral.cc: New test.
	* testsuite/std/concepts/concepts.lang/concept.assignable/1.cc: New
	test.
	* testsuite/std/concepts/concepts.lang/concept.common/1.cc: New test.
	* testsuite/std/concepts/concepts.lang/concept.commonref/1.cc: New
	test.
	* testsuite/std/concepts/concepts.lang/concept.constructible/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.convertible/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.copyconstructible/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.defaultconstructible/
	1.cc: New test.
	* testsuite/std/concepts/concepts.lang/concept.derived/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.destructible/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.moveconstructible/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.same/1.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swappable.cc:
	New test.
	* testsuite/std/concepts/concepts.lang/concept.swappable/
	swappable_with.cc: New test.
	* testsuite/std/concepts/concepts.object/copyable.cc: New test.
	* testsuite/std/concepts/concepts.object/movable.cc: New test.
	* testsuite/std/concepts/concepts.object/regular.cc: New test.
	* testsuite/std/concepts/concepts.object/semiregular.cc: New test.

From-SVN: r276892

1 files changed, 351 insertions, 0 deletions

diff --git a/libstdc++-v3/include/std/concepts b/libstdc++-v3/include/std/concepts
new file mode 100644
index 0000000..6b1150a
--- /dev/null
+++ b/libstdc++-v3/include/std/concepts
@@ -0,0 +1,351 @@
+// <concepts> -*- C++ -*-
+
+// Copyright (C) 2019 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received __a copy of the GNU General Public License and
+// __a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file include/concepts
+ *  This is __a Standard C++ Library header.
+ *  @ingroup concepts
+ */
+
+#ifndef _GLIBCXX_CONCEPTS
+#define _GLIBCXX_CONCEPTS 1
+
+#if __cplusplus > 201703L && __cpp_concepts
+
+#pragma GCC system_header
+
+/**
+ * @defgroup concepts Concepts
+ * @ingroup utilities
+ *
+ * Concepts for checking type requirements.
+ */
+
+#include <type_traits>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+#define __cpp_lib_concepts 201806L
+
+  // [concepts.lang], language-related concepts
+
+  namespace __detail
+  {
+    template<typename _Tp, typename _Up>
+      concept __same_as = __is_same_as(_Tp, _Up);
+  } // namespace __detail
+
+  /// [concept.same], concept same_as
+  template<typename _Tp, typename _Up>
+    concept same_as
+      = __detail::__same_as<_Tp, _Up> && __detail::__same_as<_Up, _Tp>;
+
+  /// [concept.derived], concept derived_from
+  template<typename _Derived, typename _Base>
+    concept derived_from = __is_base_of(_Base, _Derived)
+      && is_convertible_v<const volatile _Derived*, const volatile _Base*>;
+
+  /// [concept.convertible], concept convertible_to
+  template<typename _From, typename _To>
+    concept convertible_to = is_convertible_v<_From, _To>
+      && requires(add_rvalue_reference_t<_From> (&__f)()) {
+	  static_cast<_To>(__f());
+      };
+
+  /// [concept.commonref], concept common_reference_with
+  template<typename _Tp, typename _Up>
+    concept common_reference_with
+      = same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>>
+      && convertible_to<_Tp, common_reference_t<_Tp, _Up>>
+      && convertible_to<_Up, common_reference_t<_Tp, _Up>>;
+
+  /// [concept.common], concept common_with
+  template<typename _Tp, typename _Up>
+    concept common_with
+      = same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>>
+      && requires {
+	static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>());
+	static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>());
+      }
+      && common_reference_with<add_lvalue_reference_t<const _Tp>,
+			       add_lvalue_reference_t<const _Up>>
+      && common_reference_with<add_lvalue_reference_t<common_type_t<_Tp, _Up>>,
+			       common_reference_t<
+				 add_lvalue_reference_t<const _Tp>,
+				 add_lvalue_reference_t<const _Up>>>;
+
+  // [concepts.arithmetic], arithmetic concepts
+
+  template<typename _Tp>
+    concept integral = is_integral_v<_Tp>;
+
+  template<typename _Tp>
+    concept signed_integral = integral<_Tp> && is_signed_v<_Tp>;
+
+  template<typename _Tp>
+    concept unsigned_integral = integral<_Tp> && !signed_integral<_Tp>;
+
+  template<typename _Tp>
+    concept floating_point = is_floating_point_v<_Tp>;
+
+  namespace __detail
+  {
+    template<typename _Tp>
+      using __cref = const remove_reference_t<_Tp>&;
+  } // namespace __detail
+
+  /// [concept.assignable], concept assignable_from
+  template<typename _Lhs, typename _Rhs>
+    concept assignable_from
+      = is_lvalue_reference_v<_Lhs>
+      && common_reference_with<__detail::__cref<_Lhs>, __detail::__cref<_Rhs>>
+      && requires(_Lhs __lhs, _Rhs&& __rhs) {
+	{ __lhs = static_cast<_Rhs&&>(__rhs) } -> same_as<_Lhs>;
+      };
+
+  /// [concept.destructible], concept destructible
+  template<typename _Tp>
+    concept destructible = is_nothrow_destructible_v<_Tp>;
+
+  /// [concept.constructible], concept constructible_from
+  template<typename _Tp, typename... _Args>
+    concept constructible_from
+      = destructible<_Tp> && is_constructible_v<_Tp, _Args...>;
+
+  /// [concept.defaultconstructible], concept default_constructible
+  template<typename _Tp>
+    concept default_constructible = constructible_from<_Tp>;
+
+  /// [concept.moveconstructible], concept move_constructible
+  template<typename _Tp>
+    concept move_constructible
+    = constructible_from<_Tp, _Tp> && convertible_to<_Tp, _Tp>;
+
+  /// [concept.copyconstructible], concept copy_constructible
+  template<typename _Tp>
+    concept copy_constructible
+      = move_constructible<_Tp>
+      && constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp>
+      && constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp>
+      && constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>;
+
+  // [concept.swappable], concept swappable
+
+  namespace ranges
+  {
+    namespace __cust_swap
+    {
+      template<typename _Tp> void swap(_Tp&, _Tp&) = delete;
+
+      template<typename _Tp>
+	concept __class_or_enum
+	  = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>;
+
+      template<typename _Tp, typename _Up>
+	concept __adl_swap
+	  = (__class_or_enum<remove_cvref_t<_Tp>>
+	    || __class_or_enum<remove_cvref_t<_Up>>)
+	  && requires(_Tp&& __t, _Up&& __u) {
+	    swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u));
+	  };
+
+      struct _Swap
+      {
+	template<typename _Tp, typename _Up>
+	  requires __adl_swap<_Tp, _Up>
+	  constexpr void operator()(_Tp&& __t, _Up&& __u) const
+	  noexcept(noexcept(swap(std::declval<_Tp>(), std::declval<_Up>())))
+	  { swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); }
+
+	template<typename _Tp, typename _Up, size_t _Num>
+	  requires requires(const _Swap& __swap, _Tp& __e1, _Up& __e2) {
+	    __swap(__e1, __e2);
+	  }
+	  constexpr void
+	  operator()(_Tp (&__e1)[_Num], _Up (&__e2)[_Num]) const
+	  noexcept(noexcept(std::declval<const _Swap&>()(*__e1, *__e2)))
+	  {
+	    for (size_t __n = 0; __n < _Num; ++__n)
+	      (*this)(__e1[__n], __e2[__n]);
+	  }
+
+	template<typename _Tp>
+	  requires (!__adl_swap<_Tp&, _Tp&>
+	    && move_constructible<_Tp> && assignable_from<_Tp&, _Tp>)
+	  constexpr void
+	  operator()(_Tp& __e1, _Tp& __e2) const
+	  noexcept(is_nothrow_move_constructible_v<_Tp>
+		   && is_nothrow_move_assignable_v<_Tp>)
+	  {
+	    _Tp __tmp = static_cast<_Tp&&>(__e1);
+	    __e1 = static_cast<_Tp&&>(__e2);
+	    __e2 = static_cast<_Tp&&>(__tmp);
+	  }
+      };
+    } // namespace __cust_swap
+
+    inline namespace __cust
+    {
+      inline constexpr __cust_swap::_Swap swap{};
+    } // inline namespace __cust
+  } // namespace ranges
+
+  template<typename _Tp>
+    concept swappable
+      = requires(_Tp& __a, _Tp& __b) { ranges::swap(__a, __b); };
+
+  template<typename _Tp, typename _Up>
+    concept swappable_with = common_reference_with<_Tp, _Up>
+      && requires(_Tp&& __t, _Up&& __u) {
+	ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Tp&&>(__t));
+	ranges::swap(static_cast<_Up&&>(__u), static_cast<_Up&&>(__u));
+	ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u));
+	ranges::swap(static_cast<_Up&&>(__u), static_cast<_Tp&&>(__t));
+      };
+
+  // [concepts.object], Object concepts
+
+  template<typename _Tp>
+    concept movable = is_object_v<_Tp> && move_constructible<_Tp>
+      && assignable_from<_Tp&, _Tp> && swappable<_Tp>;
+
+  template<typename _Tp>
+    concept copyable = copy_constructible<_Tp> && movable<_Tp>
+      && assignable_from<_Tp&, const _Tp&>;
+
+  template<typename _Tp>
+    concept semiregular = copyable<_Tp> && default_constructible<_Tp>;
+
+  // [concepts.compare], comparison concepts
+
+  /// [concept.boolean], concept boolean
+  template<typename _Bp>
+    concept boolean
+      = movable<remove_cvref_t<_Bp>>
+      && requires(__detail::__cref<_Bp> __b1, __detail::__cref<_Bp> __b2,
+		  const bool __a) {
+	{ __b1 } -> convertible_to<bool>;
+	{ !__b1 } -> convertible_to<bool>;
+	{ __b1 && __b2 } -> same_as<bool>;
+	{ __b1 && __a  } -> same_as<bool>;
+	{ __a  && __b2 } -> same_as<bool>;
+	{ __b1 || __b2 } -> same_as<bool>;
+	{ __b1 || __a  } -> same_as<bool>;
+	{ __a  || __b2 } -> same_as<bool>;
+	{ __b1 == __b2 } -> convertible_to<bool>;
+	{ __b1 == __a  } -> convertible_to<bool>;
+	{ __a  == __b2 } -> convertible_to<bool>;
+	{ __b1 != __b2 } -> convertible_to<bool>;
+	{ __b1 != __a  } -> convertible_to<bool>;
+	{ __a  != __b2 } -> convertible_to<bool>;
+      };
+
+  // [concept.equalitycomparable], concept equality_comparable
+
+  namespace __detail
+  {
+    template<typename _Tp, typename _Up>
+      concept __weakly_eq_cmp_with
+	= requires(__detail::__cref<_Tp> __t, __detail::__cref<_Up> __u) {
+	  { __t == __u } -> boolean;
+	  { __t != __u } -> boolean;
+	  { __u == __t } -> boolean;
+	  { __u != __t } -> boolean;
+	};
+  } // namespace __detail
+
+  template<typename _Tp>
+    concept equality_comparable = __detail::__weakly_eq_cmp_with<_Tp, _Tp>;
+
+  template<typename _Tp, typename _Up>
+    concept equality_comparable_with
+      = equality_comparable<_Tp> && equality_comparable<_Up>
+      && common_reference_with<__detail::__cref<_Tp>, __detail::__cref<_Up>>
+      && equality_comparable<common_reference_t<__detail::__cref<_Tp>,
+						__detail::__cref<_Up>>>
+      && __detail::__weakly_eq_cmp_with<_Tp, _Up>;
+
+  // [concept.totallyordered], concept totally_ordered
+  template<typename _Tp>
+    concept totally_ordered
+      = equality_comparable<_Tp>
+      && requires(__detail::__cref<_Tp> __a, __detail::__cref<_Tp> __b) {
+	{ __a <  __b } -> boolean;
+	{ __a >  __b } -> boolean;
+	{ __a <= __b } -> boolean;
+	{ __a >= __b } -> boolean;
+      };
+
+  template<typename _Tp, typename _Up>
+    concept totally_ordered_with
+      = totally_ordered<_Tp> && totally_ordered<_Up>
+      && common_reference_with<__detail::__cref<_Tp>, __detail::__cref<_Up>>
+      && totally_ordered<common_reference_t<__detail::__cref<_Tp>,
+					    __detail::__cref<_Up>>>
+      && equality_comparable_with<_Tp, _Up>
+      && requires(__detail::__cref<_Tp> __t, __detail::__cref<_Up> __u) {
+	{ __t <  __u } -> boolean;
+	{ __t >  __u } -> boolean;
+	{ __t <= __u } -> boolean;
+	{ __t >= __u } -> boolean;
+	{ __u <  __t } -> boolean;
+	{ __u >  __t } -> boolean;
+	{ __u <= __t } -> boolean;
+	{ __u >= __t } -> boolean;
+      };
+
+  template<typename _Tp>
+    concept regular = semiregular<_Tp> && equality_comparable<_Tp>;
+
+  // [concepts.callable], callable concepts
+
+  // [concept.invocable], concept invocable
+  template<typename _Fn, typename... _Args>
+    concept invocable = is_invocable_v<_Fn, _Args...>;
+
+  // [concept.regularinvocable], concept regular_invocable
+  template<typename _Fn, typename... _Args>
+    concept regular_invocable = invocable<_Fn, _Args...>;
+
+  // [concept.predicate], concept predicate
+  template<typename _Fn, typename... _Args>
+    concept predicate = regular_invocable<_Fn, _Args...>
+      && boolean<invoke_result_t<_Fn, _Args...>>;
+
+  // [concept.relation], concept relation
+  template<typename _Rel, typename _Tp, typename _Up>
+    concept relation
+      = predicate<_Rel, _Tp, _Tp> && predicate<_Rel, _Up, _Up>
+      && predicate<_Rel, _Tp, _Up> && predicate<_Rel, _Up, _Tp>;
+
+  // [concept.strictweakorder], concept strict_weak_order
+  template<typename _Rel, typename _Tp, typename _Up>
+    concept strict_weak_order = relation<_Rel, _Tp, _Up>;
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+#endif // C++2a
+
+#endif /* _GLIBCXX_CONCEPTS */