Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 2236 insertions, 0 deletions

diff --git a/gcc-4.9/libstdc++-v3/include/std/type_traits b/gcc-4.9/libstdc++-v3/include/std/type_traits
new file mode 100644
index 0000000..4b434a6
--- /dev/null
+++ b/gcc-4.9/libstdc++-v3/include/std/type_traits
@@ -0,0 +1,2236 @@
+// C++11 <type_traits> -*- C++ -*-
+
+// Copyright (C) 2007-2014 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/type_traits
+ *  This is a Standard C++ Library header.
+ */
+
+#ifndef _GLIBCXX_TYPE_TRAITS
+#define _GLIBCXX_TYPE_TRAITS 1
+
+#pragma GCC system_header
+
+#if __cplusplus < 201103L
+# include <bits/c++0x_warning.h>
+#else
+
+#include <bits/c++config.h>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  /**
+   * @defgroup metaprogramming Metaprogramming
+   * @ingroup utilities
+   *
+   * Template utilities for compile-time introspection and modification,
+   * including type classification traits, type property inspection traits
+   * and type transformation traits.
+   *
+   * @{
+   */
+
+  /// integral_constant
+  template<typename _Tp, _Tp __v>
+    struct integral_constant
+    {
+      static constexpr _Tp                  value = __v;
+      typedef _Tp                           value_type;
+      typedef integral_constant<_Tp, __v>   type;
+      constexpr operator value_type() const { return value; }
+#if __cplusplus > 201103L
+      constexpr value_type operator()() const { return value; }
+#endif
+    };
+  
+  template<typename _Tp, _Tp __v>
+    constexpr _Tp integral_constant<_Tp, __v>::value;
+
+  /// The type used as a compile-time boolean with true value.
+  typedef integral_constant<bool, true>     true_type;
+
+  /// The type used as a compile-time boolean with false value.
+  typedef integral_constant<bool, false>    false_type;
+
+  // Meta programming helper types.
+
+  template<bool, typename, typename>
+    struct conditional;
+
+  template<typename...>
+    struct __or_;
+
+  template<>
+    struct __or_<>
+    : public false_type
+    { };
+
+  template<typename _B1>
+    struct __or_<_B1>
+    : public _B1
+    { };
+
+  template<typename _B1, typename _B2>
+    struct __or_<_B1, _B2>
+    : public conditional<_B1::value, _B1, _B2>::type
+    { };
+
+  template<typename _B1, typename _B2, typename _B3, typename... _Bn>
+    struct __or_<_B1, _B2, _B3, _Bn...>
+    : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type
+    { };
+
+  template<typename...>
+    struct __and_;
+
+  template<>
+    struct __and_<>
+    : public true_type
+    { };
+
+  template<typename _B1>
+    struct __and_<_B1>
+    : public _B1
+    { };
+
+  template<typename _B1, typename _B2>
+    struct __and_<_B1, _B2>
+    : public conditional<_B1::value, _B2, _B1>::type
+    { };
+
+  template<typename _B1, typename _B2, typename _B3, typename... _Bn>
+    struct __and_<_B1, _B2, _B3, _Bn...>
+    : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type
+    { };
+
+  template<typename _Pp>
+    struct __not_
+    : public integral_constant<bool, !_Pp::value>
+    { };
+
+  // For several sfinae-friendly trait implementations we transport both the
+  // result information (as the member type) and the failure information (no
+  // member type). This is very similar to std::enable_if, but we cannot use
+  // them, because we need to derive from them as an implementation detail.
+
+  template<typename _Tp>
+    struct __success_type
+    { typedef _Tp type; };
+
+  struct __failure_type
+  { };
+
+  // Primary type categories.
+
+  template<typename>
+    struct remove_cv;
+
+  template<typename>
+    struct __is_void_helper
+    : public false_type { };
+
+  template<>
+    struct __is_void_helper<void>
+    : public true_type { };
+
+  /// is_void
+  template<typename _Tp>
+    struct is_void
+    : public __is_void_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  template<typename>
+    struct __is_integral_helper
+    : public false_type { };
+
+  template<>
+    struct __is_integral_helper<bool>
+    : public true_type { };
+  
+  template<>
+    struct __is_integral_helper<char>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<signed char>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned char>
+    : public true_type { };
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+  template<>
+    struct __is_integral_helper<wchar_t>
+    : public true_type { };
+#endif
+
+  template<>
+    struct __is_integral_helper<char16_t>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<char32_t>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<short>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned short>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<int>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned int>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<long>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned long>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<long long>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned long long>
+    : public true_type { };
+
+#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128)
+  template<>
+    struct __is_integral_helper<__int128>
+    : public true_type { };
+
+  template<>
+    struct __is_integral_helper<unsigned __int128>
+    : public true_type { };
+#endif
+
+  /// is_integral
+  template<typename _Tp>
+    struct is_integral
+    : public __is_integral_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  template<typename>
+    struct __is_floating_point_helper
+    : public false_type { };
+
+  template<>
+    struct __is_floating_point_helper<float>
+    : public true_type { };
+
+  template<>
+    struct __is_floating_point_helper<double>
+    : public true_type { };
+
+  template<>
+    struct __is_floating_point_helper<long double>
+    : public true_type { };
+
+#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
+  template<>
+    struct __is_floating_point_helper<__float128>
+    : public true_type { };
+#endif
+
+  /// is_floating_point
+  template<typename _Tp>
+    struct is_floating_point
+    : public __is_floating_point_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  /// is_array
+  template<typename>
+    struct is_array
+    : public false_type { };
+
+  template<typename _Tp, std::size_t _Size>
+    struct is_array<_Tp[_Size]>
+    : public true_type { };
+
+  template<typename _Tp>
+    struct is_array<_Tp[]>
+    : public true_type { };
+
+  template<typename>
+    struct __is_pointer_helper
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_pointer_helper<_Tp*>
+    : public true_type { };
+
+  /// is_pointer
+  template<typename _Tp>
+    struct is_pointer
+    : public __is_pointer_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  /// is_lvalue_reference
+  template<typename>
+    struct is_lvalue_reference
+    : public false_type { };
+
+  template<typename _Tp>
+    struct is_lvalue_reference<_Tp&>
+    : public true_type { };
+
+  /// is_rvalue_reference
+  template<typename>
+    struct is_rvalue_reference
+    : public false_type { };
+
+  template<typename _Tp>
+    struct is_rvalue_reference<_Tp&&>
+    : public true_type { };
+
+  template<typename>
+    struct is_function;
+
+  template<typename>
+    struct __is_member_object_pointer_helper
+    : public false_type { };
+
+  template<typename _Tp, typename _Cp>
+    struct __is_member_object_pointer_helper<_Tp _Cp::*>
+    : public integral_constant<bool, !is_function<_Tp>::value> { };
+
+  /// is_member_object_pointer
+  template<typename _Tp>
+    struct is_member_object_pointer
+    : public __is_member_object_pointer_helper<
+				typename remove_cv<_Tp>::type>::type
+    { };
+
+  template<typename>
+    struct __is_member_function_pointer_helper
+    : public false_type { };
+
+  template<typename _Tp, typename _Cp>
+    struct __is_member_function_pointer_helper<_Tp _Cp::*>
+    : public integral_constant<bool, is_function<_Tp>::value> { };
+
+  /// is_member_function_pointer
+  template<typename _Tp>
+    struct is_member_function_pointer
+    : public __is_member_function_pointer_helper<
+				typename remove_cv<_Tp>::type>::type
+    { };
+
+  /// is_enum
+  template<typename _Tp>
+    struct is_enum
+    : public integral_constant<bool, __is_enum(_Tp)>
+    { };
+
+  /// is_union
+  template<typename _Tp>
+    struct is_union
+    : public integral_constant<bool, __is_union(_Tp)>
+    { };
+
+  /// is_class
+  template<typename _Tp>
+    struct is_class
+    : public integral_constant<bool, __is_class(_Tp)>
+    { };
+
+  /// is_function
+  template<typename>
+    struct is_function
+    : public false_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...)>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......)>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) volatile>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) volatile &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) volatile &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) volatile>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) volatile &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) volatile &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const volatile>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const volatile &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes...) const volatile &&>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const volatile>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const volatile &>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct is_function<_Res(_ArgTypes......) const volatile &&>
+    : public true_type { };
+
+  template<typename>
+    struct __is_null_pointer_helper
+    : public false_type { };
+
+  template<>
+    struct __is_null_pointer_helper<std::nullptr_t>
+    : public true_type { };
+
+  /// is_null_pointer (LWG 2247).
+  template<typename _Tp>
+    struct is_null_pointer
+    : public __is_null_pointer_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  /// __is_nullptr_t (extension).
+  template<typename _Tp>
+    struct __is_nullptr_t
+    : public is_null_pointer<_Tp>
+    { };
+
+  // Composite type categories.
+
+  /// is_reference
+  template<typename _Tp>
+    struct is_reference
+    : public __or_<is_lvalue_reference<_Tp>,
+                   is_rvalue_reference<_Tp>>::type
+    { };
+
+  /// is_arithmetic
+  template<typename _Tp>
+    struct is_arithmetic
+    : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
+    { };
+
+  /// is_fundamental
+  template<typename _Tp>
+    struct is_fundamental
+    : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
+		   is_null_pointer<_Tp>>::type
+    { };
+
+  /// is_object
+  template<typename _Tp>
+    struct is_object
+    : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
+                          is_void<_Tp>>>::type
+    { };
+
+  template<typename>
+    struct is_member_pointer;
+
+  /// is_scalar
+  template<typename _Tp>
+    struct is_scalar
+    : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
+                   is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
+    { };
+
+  /// is_compound
+  template<typename _Tp>
+    struct is_compound
+    : public integral_constant<bool, !is_fundamental<_Tp>::value> { };
+
+  template<typename _Tp>
+    struct __is_member_pointer_helper
+    : public false_type { };
+
+  template<typename _Tp, typename _Cp>
+    struct __is_member_pointer_helper<_Tp _Cp::*>
+    : public true_type { };
+
+  /// is_member_pointer
+  template<typename _Tp>
+    struct is_member_pointer
+    : public __is_member_pointer_helper<typename remove_cv<_Tp>::type>::type
+    { };
+
+  // Utility to detect referenceable types ([defns.referenceable]).
+
+  template<typename _Tp>
+    struct __is_referenceable
+    : public __or_<is_object<_Tp>, is_reference<_Tp>>::type
+    { };
+
+  template<typename _Res, typename... _Args>
+    struct __is_referenceable<_Res(_Args...)>
+    : public true_type
+    { };
+
+  template<typename _Res, typename... _Args>
+    struct __is_referenceable<_Res(_Args......)>
+    : public true_type
+    { };
+
+  // Type properties.
+
+  /// is_const
+  template<typename>
+    struct is_const
+    : public false_type { };
+
+  template<typename _Tp>
+    struct is_const<_Tp const>
+    : public true_type { };
+  
+  /// is_volatile
+  template<typename>
+    struct is_volatile
+    : public false_type { };
+
+  template<typename _Tp>
+    struct is_volatile<_Tp volatile>
+    : public true_type { };
+
+  /// is_trivial
+  template<typename _Tp>
+    struct is_trivial
+    : public integral_constant<bool, __is_trivial(_Tp)>
+    { };
+
+  // is_trivially_copyable (still unimplemented)
+
+  /// is_standard_layout
+  template<typename _Tp>
+    struct is_standard_layout
+    : public integral_constant<bool, __is_standard_layout(_Tp)>
+    { };
+
+  /// is_pod
+  // Could use is_standard_layout && is_trivial instead of the builtin.
+  template<typename _Tp>
+    struct is_pod
+    : public integral_constant<bool, __is_pod(_Tp)>
+    { };
+
+  /// is_literal_type
+  template<typename _Tp>
+    struct is_literal_type
+    : public integral_constant<bool, __is_literal_type(_Tp)>
+    { };
+
+  /// is_empty
+  template<typename _Tp>
+    struct is_empty
+    : public integral_constant<bool, __is_empty(_Tp)>
+    { };
+
+  /// is_polymorphic
+  template<typename _Tp>
+    struct is_polymorphic
+    : public integral_constant<bool, __is_polymorphic(_Tp)>
+    { };
+
+  /// is_abstract
+  template<typename _Tp>
+    struct is_abstract
+    : public integral_constant<bool, __is_abstract(_Tp)>
+    { };
+
+  template<typename _Tp,
+	   bool = is_arithmetic<_Tp>::value>
+    struct __is_signed_helper
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_signed_helper<_Tp, true>
+    : public integral_constant<bool, _Tp(-1) < _Tp(0)>
+    { };
+
+  /// is_signed
+  template<typename _Tp>
+    struct is_signed
+    : public __is_signed_helper<_Tp>::type
+    { };
+
+  /// is_unsigned
+  template<typename _Tp>
+    struct is_unsigned
+    : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>::type
+    { };
+
+
+  // Destructible and constructible type properties.
+
+  template<typename>
+    struct add_rvalue_reference;
+
+  /**
+   *  @brief  Utility to simplify expressions used in unevaluated operands
+   *  @ingroup utilities
+   */
+  template<typename _Tp>
+    typename add_rvalue_reference<_Tp>::type declval() noexcept;
+
+  template<typename, unsigned = 0>
+    struct extent;
+
+  template<typename>
+    struct remove_all_extents;
+
+  template<typename _Tp>
+    struct __is_array_known_bounds
+    : public integral_constant<bool, (extent<_Tp>::value > 0)>
+    { };
+
+  template<typename _Tp>
+    struct __is_array_unknown_bounds
+    : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>::type
+    { };
+    
+  // In N3290 is_destructible does not say anything about function
+  // types and abstract types, see LWG 2049. This implementation
+  // describes function types as non-destructible and all complete
+  // object types as destructible, iff the explicit destructor
+  // call expression is wellformed.
+  struct __do_is_destructible_impl
+  {
+    template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
+      static true_type __test(int);
+
+    template<typename>
+      static false_type __test(...);
+  };
+
+  template<typename _Tp>
+    struct __is_destructible_impl
+    : public __do_is_destructible_impl
+    {
+      typedef decltype(__test<_Tp>(0)) type;
+    };
+
+  template<typename _Tp,
+           bool = __or_<is_void<_Tp>,
+                        __is_array_unknown_bounds<_Tp>,
+                        is_function<_Tp>>::value,
+           bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
+    struct __is_destructible_safe;
+
+  template<typename _Tp>
+    struct __is_destructible_safe<_Tp, false, false>
+    : public __is_destructible_impl<typename
+               remove_all_extents<_Tp>::type>::type
+    { };
+
+  template<typename _Tp>
+    struct __is_destructible_safe<_Tp, true, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_destructible_safe<_Tp, false, true>
+    : public true_type { };
+
+  /// is_destructible
+  template<typename _Tp>
+    struct is_destructible
+    : public __is_destructible_safe<_Tp>::type
+    { };
+
+  // is_nothrow_destructible requires that is_destructible is
+  // satisfied as well.  We realize that by mimicing the
+  // implementation of is_destructible but refer to noexcept(expr)
+  // instead of decltype(expr).
+  struct __do_is_nt_destructible_impl
+  {
+    template<typename _Tp>
+      static integral_constant<bool, noexcept(declval<_Tp&>().~_Tp())>
+        __test(int);
+
+    template<typename>
+      static false_type __test(...);
+  };
+
+  template<typename _Tp>
+    struct __is_nt_destructible_impl
+    : public __do_is_nt_destructible_impl
+    {
+      typedef decltype(__test<_Tp>(0)) type;
+    };
+
+  template<typename _Tp,
+           bool = __or_<is_void<_Tp>,
+                        __is_array_unknown_bounds<_Tp>,
+                        is_function<_Tp>>::value,
+           bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
+    struct __is_nt_destructible_safe;
+
+  template<typename _Tp>
+    struct __is_nt_destructible_safe<_Tp, false, false>
+    : public __is_nt_destructible_impl<typename
+               remove_all_extents<_Tp>::type>::type
+    { };
+
+  template<typename _Tp>
+    struct __is_nt_destructible_safe<_Tp, true, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_nt_destructible_safe<_Tp, false, true>
+    : public true_type { };
+
+  /// is_nothrow_destructible
+  template<typename _Tp>
+    struct is_nothrow_destructible
+    : public __is_nt_destructible_safe<_Tp>::type
+    { };
+
+  struct __do_is_default_constructible_impl
+  {
+    template<typename _Tp, typename = decltype(_Tp())>
+      static true_type __test(int);
+
+    template<typename>
+      static false_type __test(...);
+  };
+
+  template<typename _Tp>
+    struct __is_default_constructible_impl
+    : public __do_is_default_constructible_impl
+    {
+      typedef decltype(__test<_Tp>(0)) type;
+    };
+
+  template<typename _Tp>
+    struct __is_default_constructible_atom
+    : public __and_<__not_<is_void<_Tp>>,
+                    __is_default_constructible_impl<_Tp>>::type
+    { };
+
+  template<typename _Tp, bool = is_array<_Tp>::value>
+    struct __is_default_constructible_safe;
+
+  // The following technique is a workaround for a current core language
+  // restriction, which does not allow for array types to occur in 
+  // functional casts of the form T().  Complete arrays can be default-
+  // constructed, if the element type is default-constructible, but 
+  // arrays with unknown bounds are not.
+  template<typename _Tp>
+    struct __is_default_constructible_safe<_Tp, true>
+    : public __and_<__is_array_known_bounds<_Tp>,
+		    __is_default_constructible_atom<typename
+                      remove_all_extents<_Tp>::type>>::type
+    { };
+
+  template<typename _Tp>
+    struct __is_default_constructible_safe<_Tp, false>
+    : public __is_default_constructible_atom<_Tp>::type
+    { };
+
+  /// is_default_constructible
+  template<typename _Tp>
+    struct is_default_constructible
+    : public __is_default_constructible_safe<_Tp>::type
+    { };
+
+
+  // Implementation of is_constructible.
+
+  // The hardest part of this trait is the binary direct-initialization
+  // case, because we hit into a functional cast of the form T(arg).
+  // This implementation uses different strategies depending on the
+  // target type to reduce the test overhead as much as possible:
+  //
+  // a) For a reference target type, we use a static_cast expression 
+  //    modulo its extra cases.
+  //
+  // b) For a non-reference target type we use a ::new expression.
+  struct __do_is_static_castable_impl
+  {
+    template<typename _From, typename _To, typename
+             = decltype(static_cast<_To>(declval<_From>()))>
+      static true_type __test(int);
+
+    template<typename, typename>
+      static false_type __test(...);
+  };
+
+  template<typename _From, typename _To>
+    struct __is_static_castable_impl
+    : public __do_is_static_castable_impl
+    {
+      typedef decltype(__test<_From, _To>(0)) type;
+    };
+
+  template<typename _From, typename _To>
+    struct __is_static_castable_safe
+    : public __is_static_castable_impl<_From, _To>::type
+    { };
+
+  // __is_static_castable
+  template<typename _From, typename _To>
+    struct __is_static_castable
+    : public integral_constant<bool, (__is_static_castable_safe<
+				      _From, _To>::value)>
+    { };
+
+  // Implementation for non-reference types. To meet the proper
+  // variable definition semantics, we also need to test for
+  // is_destructible in this case.
+  // This form should be simplified by a single expression:
+  // ::delete ::new _Tp(declval<_Arg>()), see c++/51222.
+  struct __do_is_direct_constructible_impl
+  {
+    template<typename _Tp, typename _Arg, typename
+	     = decltype(::new _Tp(declval<_Arg>()))>
+      static true_type __test(int);
+
+    template<typename, typename>
+      static false_type __test(...);
+  };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_direct_constructible_impl
+    : public __do_is_direct_constructible_impl
+    {
+      typedef decltype(__test<_Tp, _Arg>(0)) type;
+    };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_direct_constructible_new_safe
+    : public __and_<is_destructible<_Tp>,
+                    __is_direct_constructible_impl<_Tp, _Arg>>::type
+    { };
+
+  template<typename, typename>
+    struct is_same;
+
+  template<typename, typename>
+    struct is_base_of;
+
+  template<typename>
+    struct remove_reference;
+
+  template<typename _From, typename _To, bool
+           = __not_<__or_<is_void<_From>, 
+                          is_function<_From>>>::value>
+    struct __is_base_to_derived_ref;
+
+  // Detect whether we have a downcast situation during
+  // reference binding.
+  template<typename _From, typename _To>
+    struct __is_base_to_derived_ref<_From, _To, true>
+    {
+      typedef typename remove_cv<typename remove_reference<_From
+        >::type>::type __src_t;
+      typedef typename remove_cv<typename remove_reference<_To
+        >::type>::type __dst_t;
+      typedef __and_<__not_<is_same<__src_t, __dst_t>>,
+		     is_base_of<__src_t, __dst_t>> type;
+      static constexpr bool value = type::value;
+    };
+
+  template<typename _From, typename _To>
+    struct __is_base_to_derived_ref<_From, _To, false>
+    : public false_type
+    { };
+
+  template<typename _From, typename _To, bool
+           = __and_<is_lvalue_reference<_From>,
+                    is_rvalue_reference<_To>>::value>
+    struct __is_lvalue_to_rvalue_ref;
+
+  // Detect whether we have an lvalue of non-function type
+  // bound to a reference-compatible rvalue-reference.
+  template<typename _From, typename _To>
+    struct __is_lvalue_to_rvalue_ref<_From, _To, true>
+    {
+      typedef typename remove_cv<typename remove_reference<
+        _From>::type>::type __src_t;
+      typedef typename remove_cv<typename remove_reference<
+        _To>::type>::type __dst_t;
+      typedef __and_<__not_<is_function<__src_t>>, 
+        __or_<is_same<__src_t, __dst_t>,
+		    is_base_of<__dst_t, __src_t>>> type;
+      static constexpr bool value = type::value;
+    };
+
+  template<typename _From, typename _To>
+    struct __is_lvalue_to_rvalue_ref<_From, _To, false>
+    : public false_type
+    { };
+
+  // Here we handle direct-initialization to a reference type as 
+  // equivalent to a static_cast modulo overshooting conversions.
+  // These are restricted to the following conversions:
+  //    a) A base class value to a derived class reference
+  //    b) An lvalue to an rvalue-reference of reference-compatible 
+  //       types that are not functions
+  template<typename _Tp, typename _Arg>
+    struct __is_direct_constructible_ref_cast
+    : public __and_<__is_static_castable<_Arg, _Tp>,
+                    __not_<__or_<__is_base_to_derived_ref<_Arg, _Tp>,
+                                 __is_lvalue_to_rvalue_ref<_Arg, _Tp>
+                   >>>::type
+    { };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_direct_constructible_new
+    : public conditional<is_reference<_Tp>::value,
+			 __is_direct_constructible_ref_cast<_Tp, _Arg>,
+			 __is_direct_constructible_new_safe<_Tp, _Arg>
+			 >::type
+    { };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_direct_constructible
+    : public __is_direct_constructible_new<_Tp, _Arg>::type
+    { };
+
+  // Since default-construction and binary direct-initialization have
+  // been handled separately, the implementation of the remaining
+  // n-ary construction cases is rather straightforward. We can use
+  // here a functional cast, because array types are excluded anyway
+  // and this form is never interpreted as a C cast.
+  struct __do_is_nary_constructible_impl
+  {
+    template<typename _Tp, typename... _Args, typename
+             = decltype(_Tp(declval<_Args>()...))>
+      static true_type __test(int);
+
+    template<typename, typename...>
+      static false_type __test(...);
+  };
+
+  template<typename _Tp, typename... _Args>
+    struct __is_nary_constructible_impl
+    : public __do_is_nary_constructible_impl
+    {
+      typedef decltype(__test<_Tp, _Args...>(0)) type;
+    };
+
+  template<typename _Tp, typename... _Args>
+    struct __is_nary_constructible
+    : public __is_nary_constructible_impl<_Tp, _Args...>::type
+    {
+      static_assert(sizeof...(_Args) > 1,
+                    "Only useful for > 1 arguments");
+    };
+
+  template<typename _Tp, typename... _Args>
+    struct __is_constructible_impl
+    : public __is_nary_constructible<_Tp, _Args...>
+    { };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_constructible_impl<_Tp, _Arg>
+    : public __is_direct_constructible<_Tp, _Arg>
+    { };
+
+  template<typename _Tp>
+    struct __is_constructible_impl<_Tp>
+    : public is_default_constructible<_Tp>
+    { };
+
+  /// is_constructible
+  template<typename _Tp, typename... _Args>
+    struct is_constructible
+    : public __is_constructible_impl<_Tp, _Args...>::type
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_copy_constructible_impl;
+
+  template<typename _Tp>
+    struct __is_copy_constructible_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_copy_constructible_impl<_Tp, true>
+    : public is_constructible<_Tp, const _Tp&>
+    { };
+
+  /// is_copy_constructible
+  template<typename _Tp>
+    struct is_copy_constructible
+    : public __is_copy_constructible_impl<_Tp>
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_move_constructible_impl;
+
+  template<typename _Tp>
+    struct __is_move_constructible_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_move_constructible_impl<_Tp, true>
+    : public is_constructible<_Tp, _Tp&&>
+    { };
+
+  /// is_move_constructible
+  template<typename _Tp>
+    struct is_move_constructible
+    : public __is_move_constructible_impl<_Tp>
+    { };
+
+  template<typename _Tp>
+    struct __is_nt_default_constructible_atom
+    : public integral_constant<bool, noexcept(_Tp())>
+    { };
+
+  template<typename _Tp, bool = is_array<_Tp>::value>
+    struct __is_nt_default_constructible_impl;
+
+  template<typename _Tp>
+    struct __is_nt_default_constructible_impl<_Tp, true>
+    : public __and_<__is_array_known_bounds<_Tp>,
+		    __is_nt_default_constructible_atom<typename
+                      remove_all_extents<_Tp>::type>>::type
+    { };
+
+  template<typename _Tp>
+    struct __is_nt_default_constructible_impl<_Tp, false>
+    : public __is_nt_default_constructible_atom<_Tp>
+    { };
+
+  /// is_nothrow_default_constructible
+  template<typename _Tp>
+    struct is_nothrow_default_constructible
+    : public __and_<is_default_constructible<_Tp>,
+                    __is_nt_default_constructible_impl<_Tp>>::type
+    { };
+
+  template<typename _Tp, typename... _Args>
+    struct __is_nt_constructible_impl
+    : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
+    { };
+
+  template<typename _Tp, typename _Arg>
+    struct __is_nt_constructible_impl<_Tp, _Arg>
+    : public integral_constant<bool,
+                               noexcept(static_cast<_Tp>(declval<_Arg>()))>
+    { };
+
+  template<typename _Tp>
+    struct __is_nt_constructible_impl<_Tp>
+    : public is_nothrow_default_constructible<_Tp>
+    { };
+
+  /// is_nothrow_constructible
+  template<typename _Tp, typename... _Args>
+    struct is_nothrow_constructible
+    : public __and_<is_constructible<_Tp, _Args...>,
+		    __is_nt_constructible_impl<_Tp, _Args...>>::type
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_nothrow_copy_constructible_impl;
+
+  template<typename _Tp>
+    struct __is_nothrow_copy_constructible_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_nothrow_copy_constructible_impl<_Tp, true>
+    : public is_nothrow_constructible<_Tp, const _Tp&>
+    { };
+
+  /// is_nothrow_copy_constructible
+  template<typename _Tp>
+    struct is_nothrow_copy_constructible
+    : public __is_nothrow_copy_constructible_impl<_Tp>
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_nothrow_move_constructible_impl;
+
+  template<typename _Tp>
+    struct __is_nothrow_move_constructible_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_nothrow_move_constructible_impl<_Tp, true>
+    : public is_nothrow_constructible<_Tp, _Tp&&>
+    { };
+
+  /// is_nothrow_move_constructible
+  template<typename _Tp>
+    struct is_nothrow_move_constructible
+    : public __is_nothrow_move_constructible_impl<_Tp>
+    { };
+
+  template<typename _Tp, typename _Up>
+    class __is_assignable_helper
+    {
+      template<typename _Tp1, typename _Up1,
+	       typename = decltype(declval<_Tp1>() = declval<_Up1>())>
+	static true_type
+	__test(int);
+
+      template<typename, typename>
+	static false_type
+	__test(...);
+
+    public:
+      typedef decltype(__test<_Tp, _Up>(0)) type;
+    };
+
+  /// is_assignable
+  template<typename _Tp, typename _Up>
+    struct is_assignable
+      : public __is_assignable_helper<_Tp, _Up>::type
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_copy_assignable_impl;
+
+  template<typename _Tp>
+    struct __is_copy_assignable_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_copy_assignable_impl<_Tp, true>
+    : public is_assignable<_Tp&, const _Tp&>
+    { };
+
+  /// is_copy_assignable
+  template<typename _Tp>
+    struct is_copy_assignable
+    : public __is_copy_assignable_impl<_Tp>
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_move_assignable_impl;
+
+  template<typename _Tp>
+    struct __is_move_assignable_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_move_assignable_impl<_Tp, true>
+    : public is_assignable<_Tp&, _Tp&&>
+    { };
+
+  /// is_move_assignable
+  template<typename _Tp>
+    struct is_move_assignable
+    : public __is_move_assignable_impl<_Tp>
+    { };
+
+  template<typename _Tp, typename _Up>
+    struct __is_nt_assignable_impl
+    : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
+    { };
+
+  /// is_nothrow_assignable
+  template<typename _Tp, typename _Up>
+    struct is_nothrow_assignable
+    : public __and_<is_assignable<_Tp, _Up>,
+		    __is_nt_assignable_impl<_Tp, _Up>>::type
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_nt_copy_assignable_impl;
+
+  template<typename _Tp>
+    struct __is_nt_copy_assignable_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_nt_copy_assignable_impl<_Tp, true>
+    : public is_nothrow_assignable<_Tp&, const _Tp&>
+    { };
+
+  /// is_nothrow_copy_assignable
+  template<typename _Tp>
+    struct is_nothrow_copy_assignable
+    : public __is_nt_copy_assignable_impl<_Tp>
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __is_nt_move_assignable_impl;
+
+  template<typename _Tp>
+    struct __is_nt_move_assignable_impl<_Tp, false>
+    : public false_type { };
+
+  template<typename _Tp>
+    struct __is_nt_move_assignable_impl<_Tp, true>
+    : public is_nothrow_assignable<_Tp&, _Tp&&>
+    { };
+
+  /// is_nothrow_move_assignable
+  template<typename _Tp>
+    struct is_nothrow_move_assignable
+    : public __is_nt_move_assignable_impl<_Tp>
+    { };
+
+  /// is_trivially_constructible (still unimplemented)
+  
+  /// is_trivially_default_constructible (still unimplemented)
+
+  /// is_trivially_copy_constructible (still unimplemented)
+
+  /// is_trivially_move_constructible (still unimplemented)
+
+  /// is_trivially_assignable (still unimplemented)
+
+  /// is_trivially_copy_assignable (still unimplemented)
+
+  /// is_trivially_move_assignable (still unimplemented)
+
+  /// is_trivially_destructible
+  template<typename _Tp>
+    struct is_trivially_destructible
+    : public __and_<is_destructible<_Tp>, integral_constant<bool,
+			      __has_trivial_destructor(_Tp)>>::type
+    { };
+
+  /// has_trivial_default_constructor (temporary legacy)
+  template<typename _Tp>
+    struct has_trivial_default_constructor
+    : public integral_constant<bool, __has_trivial_constructor(_Tp)>
+    { };
+
+  /// has_trivial_copy_constructor (temporary legacy)
+  template<typename _Tp>
+    struct has_trivial_copy_constructor
+    : public integral_constant<bool, __has_trivial_copy(_Tp)>
+    { };
+
+  /// has_trivial_copy_assign (temporary legacy)
+  template<typename _Tp>
+    struct has_trivial_copy_assign
+    : public integral_constant<bool, __has_trivial_assign(_Tp)>
+    { };
+
+  /// has_virtual_destructor
+  template<typename _Tp>
+    struct has_virtual_destructor
+    : public integral_constant<bool, __has_virtual_destructor(_Tp)>
+    { };
+
+  
+  // type property queries.
+
+  /// alignment_of
+  template<typename _Tp>
+    struct alignment_of
+    : public integral_constant<std::size_t, __alignof__(_Tp)> { };
+  
+  /// rank
+  template<typename>
+    struct rank
+    : public integral_constant<std::size_t, 0> { };
+   
+  template<typename _Tp, std::size_t _Size>
+    struct rank<_Tp[_Size]>
+    : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
+
+  template<typename _Tp>
+    struct rank<_Tp[]>
+    : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
+
+  /// extent
+  template<typename, unsigned _Uint>
+    struct extent
+    : public integral_constant<std::size_t, 0> { };
+  
+  template<typename _Tp, unsigned _Uint, std::size_t _Size>
+    struct extent<_Tp[_Size], _Uint>
+    : public integral_constant<std::size_t,
+			       _Uint == 0 ? _Size : extent<_Tp,
+							   _Uint - 1>::value>
+    { };
+
+  template<typename _Tp, unsigned _Uint>
+    struct extent<_Tp[], _Uint>
+    : public integral_constant<std::size_t,
+			       _Uint == 0 ? 0 : extent<_Tp,
+						       _Uint - 1>::value>
+    { };
+
+
+  // Type relations.
+
+  /// is_same
+  template<typename, typename>
+    struct is_same
+    : public false_type { };
+
+  template<typename _Tp>
+    struct is_same<_Tp, _Tp>
+    : public true_type { };
+
+  /// is_base_of
+  template<typename _Base, typename _Derived>
+    struct is_base_of
+    : public integral_constant<bool, __is_base_of(_Base, _Derived)>
+    { };
+
+  template<typename _From, typename _To,
+           bool = __or_<is_void<_From>, is_function<_To>,
+                        is_array<_To>>::value>
+    struct __is_convertible_helper
+    { typedef typename is_void<_To>::type type; };
+
+  template<typename _From, typename _To>
+    class __is_convertible_helper<_From, _To, false>
+    {
+       template<typename _To1>
+	static void __test_aux(_To1);
+
+      template<typename _From1, typename _To1,
+	       typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
+	static true_type
+	__test(int);
+
+      template<typename, typename>
+	static false_type
+	__test(...);
+
+    public:
+      typedef decltype(__test<_From, _To>(0)) type;
+    };
+
+
+  /// is_convertible
+  template<typename _From, typename _To>
+    struct is_convertible
+    : public __is_convertible_helper<_From, _To>::type
+    { };
+
+
+  // Const-volatile modifications.
+
+  /// remove_const
+  template<typename _Tp>
+    struct remove_const
+    { typedef _Tp     type; };
+
+  template<typename _Tp>
+    struct remove_const<_Tp const>
+    { typedef _Tp     type; };
+  
+  /// remove_volatile
+  template<typename _Tp>
+    struct remove_volatile
+    { typedef _Tp     type; };
+
+  template<typename _Tp>
+    struct remove_volatile<_Tp volatile>
+    { typedef _Tp     type; };
+  
+  /// remove_cv
+  template<typename _Tp>
+    struct remove_cv
+    {
+      typedef typename
+      remove_const<typename remove_volatile<_Tp>::type>::type     type;
+    };
+  
+  /// add_const
+  template<typename _Tp>
+    struct add_const
+    { typedef _Tp const     type; };
+   
+  /// add_volatile
+  template<typename _Tp>
+    struct add_volatile
+    { typedef _Tp volatile     type; };
+  
+  /// add_cv
+  template<typename _Tp>
+    struct add_cv
+    {
+      typedef typename
+      add_const<typename add_volatile<_Tp>::type>::type     type;
+    };
+
+#if __cplusplus > 201103L
+  /// Alias template for remove_const
+  template<typename _Tp>
+    using remove_const_t = typename remove_const<_Tp>::type;
+
+  /// Alias template for remove_volatile
+  template<typename _Tp>
+    using remove_volatile_t = typename remove_volatile<_Tp>::type;
+
+  /// Alias template for remove_cv
+  template<typename _Tp>
+    using remove_cv_t = typename remove_cv<_Tp>::type;
+
+  /// Alias template for add_const
+  template<typename _Tp>
+    using add_const_t = typename add_const<_Tp>::type;
+
+  /// Alias template for add_volatile
+  template<typename _Tp>
+    using add_volatile_t = typename add_volatile<_Tp>::type;
+
+  /// Alias template for add_cv
+  template<typename _Tp>
+    using add_cv_t = typename add_cv<_Tp>::type;
+#endif
+
+  // Reference transformations.
+
+  /// remove_reference
+  template<typename _Tp>
+    struct remove_reference
+    { typedef _Tp   type; };
+
+  template<typename _Tp>
+    struct remove_reference<_Tp&>
+    { typedef _Tp   type; };
+
+  template<typename _Tp>
+    struct remove_reference<_Tp&&>
+    { typedef _Tp   type; };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __add_lvalue_reference_helper
+    { typedef _Tp   type; };
+
+  template<typename _Tp>
+    struct __add_lvalue_reference_helper<_Tp, true>
+    { typedef _Tp&   type; };
+
+  /// add_lvalue_reference
+  template<typename _Tp>
+    struct add_lvalue_reference
+    : public __add_lvalue_reference_helper<_Tp>
+    { };
+
+  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
+    struct __add_rvalue_reference_helper
+    { typedef _Tp   type; };
+
+  template<typename _Tp>
+    struct __add_rvalue_reference_helper<_Tp, true>
+    { typedef _Tp&&   type; };
+
+  /// add_rvalue_reference
+  template<typename _Tp>
+    struct add_rvalue_reference
+    : public __add_rvalue_reference_helper<_Tp>
+    { };
+
+#if __cplusplus > 201103L
+  /// Alias template for remove_reference
+  template<typename _Tp>
+    using remove_reference_t = typename remove_reference<_Tp>::type;
+
+  /// Alias template for add_lvalue_reference
+  template<typename _Tp>
+    using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
+
+  /// Alias template for add_rvalue_reference
+  template<typename _Tp>
+    using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
+#endif
+
+  // Sign modifications.
+
+  // Utility for constructing identically cv-qualified types.
+  template<typename _Unqualified, bool _IsConst, bool _IsVol>
+    struct __cv_selector;
+
+  template<typename _Unqualified>
+    struct __cv_selector<_Unqualified, false, false>
+    { typedef _Unqualified __type; };
+
+  template<typename _Unqualified>
+    struct __cv_selector<_Unqualified, false, true>
+    { typedef volatile _Unqualified __type; };
+
+  template<typename _Unqualified>
+    struct __cv_selector<_Unqualified, true, false>
+    { typedef const _Unqualified __type; };
+
+  template<typename _Unqualified>
+    struct __cv_selector<_Unqualified, true, true>
+    { typedef const volatile _Unqualified __type; };
+
+  template<typename _Qualified, typename _Unqualified,
+	   bool _IsConst = is_const<_Qualified>::value,
+	   bool _IsVol = is_volatile<_Qualified>::value>
+    class __match_cv_qualifiers
+    {
+      typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
+
+    public:
+      typedef typename __match::__type __type; 
+    };
+
+  // Utility for finding the unsigned versions of signed integral types.
+  template<typename _Tp>
+    struct __make_unsigned
+    { typedef _Tp __type; };
+
+  template<>
+    struct __make_unsigned<char>
+    { typedef unsigned char __type; };
+
+  template<>
+    struct __make_unsigned<signed char>
+    { typedef unsigned char __type; };
+
+  template<>
+    struct __make_unsigned<short>
+    { typedef unsigned short __type; };
+
+  template<>
+    struct __make_unsigned<int>
+    { typedef unsigned int __type; };
+
+  template<>
+    struct __make_unsigned<long>
+    { typedef unsigned long __type; };
+
+  template<>
+    struct __make_unsigned<long long>
+    { typedef unsigned long long __type; };
+
+#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128)
+  template<>
+    struct __make_unsigned<__int128>
+    { typedef unsigned __int128 __type; };
+#endif
+
+  // Select between integral and enum: not possible to be both.
+  template<typename _Tp, 
+	   bool _IsInt = is_integral<_Tp>::value,
+	   bool _IsEnum = is_enum<_Tp>::value>
+    class __make_unsigned_selector;
+
+  template<typename _Tp>
+    class __make_unsigned_selector<_Tp, true, false>
+    {
+      typedef __make_unsigned<typename remove_cv<_Tp>::type> __unsignedt;
+      typedef typename __unsignedt::__type __unsigned_type;
+      typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
+
+    public:
+      typedef typename __cv_unsigned::__type __type;
+    };
+
+  template<typename _Tp>
+    class __make_unsigned_selector<_Tp, false, true>
+    {
+      // With -fshort-enums, an enum may be as small as a char.
+      typedef unsigned char __smallest;
+      static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
+      static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
+      static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
+      typedef conditional<__b2, unsigned int, unsigned long> __cond2;
+      typedef typename __cond2::type __cond2_type;
+      typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
+      typedef typename __cond1::type __cond1_type;
+
+    public:
+      typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
+    };
+
+  // Given an integral/enum type, return the corresponding unsigned
+  // integer type.
+  // Primary template.
+  /// make_unsigned
+  template<typename _Tp>
+    struct make_unsigned 
+    { typedef typename __make_unsigned_selector<_Tp>::__type type; };
+
+  // Integral, but don't define.
+  template<>
+    struct make_unsigned<bool>;
+
+
+  // Utility for finding the signed versions of unsigned integral types.
+  template<typename _Tp>
+    struct __make_signed
+    { typedef _Tp __type; };
+
+  template<>
+    struct __make_signed<char>
+    { typedef signed char __type; };
+
+  template<>
+    struct __make_signed<unsigned char>
+    { typedef signed char __type; };
+
+  template<>
+    struct __make_signed<unsigned short>
+    { typedef signed short __type; };
+
+  template<>
+    struct __make_signed<unsigned int>
+    { typedef signed int __type; };
+
+  template<>
+    struct __make_signed<unsigned long>
+    { typedef signed long __type; };
+
+  template<>
+    struct __make_signed<unsigned long long>
+    { typedef signed long long __type; };
+
+#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128)
+  template<>
+    struct __make_signed<unsigned __int128>
+    { typedef __int128 __type; };
+#endif
+
+  // Select between integral and enum: not possible to be both.
+  template<typename _Tp, 
+	   bool _IsInt = is_integral<_Tp>::value,
+	   bool _IsEnum = is_enum<_Tp>::value>
+    class __make_signed_selector;
+
+  template<typename _Tp>
+    class __make_signed_selector<_Tp, true, false>
+    {
+      typedef __make_signed<typename remove_cv<_Tp>::type> __signedt;
+      typedef typename __signedt::__type __signed_type;
+      typedef __match_cv_qualifiers<_Tp, __signed_type> __cv_signed;
+
+    public:
+      typedef typename __cv_signed::__type __type;
+    };
+
+  template<typename _Tp>
+    class __make_signed_selector<_Tp, false, true>
+    {
+      // With -fshort-enums, an enum may be as small as a char.
+      typedef signed char __smallest;
+      static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
+      static const bool __b1 = sizeof(_Tp) <= sizeof(signed short);
+      static const bool __b2 = sizeof(_Tp) <= sizeof(signed int);
+      typedef conditional<__b2, signed int, signed long> __cond2;
+      typedef typename __cond2::type __cond2_type;
+      typedef conditional<__b1, signed short, __cond2_type> __cond1;
+      typedef typename __cond1::type __cond1_type;
+
+    public:
+      typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
+    };
+
+  // Given an integral/enum type, return the corresponding signed
+  // integer type.
+  // Primary template.
+  /// make_signed
+  template<typename _Tp>
+    struct make_signed 
+    { typedef typename __make_signed_selector<_Tp>::__type type; };
+
+  // Integral, but don't define.
+  template<>
+    struct make_signed<bool>;
+
+#if __cplusplus > 201103L
+  /// Alias template for make_signed
+  template<typename _Tp>
+    using make_signed_t = typename make_signed<_Tp>::type;
+
+  /// Alias template for make_unsigned
+  template<typename _Tp>
+    using make_unsigned_t = typename make_unsigned<_Tp>::type;
+#endif
+
+  // Array modifications.
+
+  /// remove_extent
+  template<typename _Tp>
+    struct remove_extent
+    { typedef _Tp     type; };
+
+  template<typename _Tp, std::size_t _Size>
+    struct remove_extent<_Tp[_Size]>
+    { typedef _Tp     type; };
+
+  template<typename _Tp>
+    struct remove_extent<_Tp[]>
+    { typedef _Tp     type; };
+
+  /// remove_all_extents
+  template<typename _Tp>
+    struct remove_all_extents
+    { typedef _Tp     type; };
+
+  template<typename _Tp, std::size_t _Size>
+    struct remove_all_extents<_Tp[_Size]>
+    { typedef typename remove_all_extents<_Tp>::type     type; };
+
+  template<typename _Tp>
+    struct remove_all_extents<_Tp[]>
+    { typedef typename remove_all_extents<_Tp>::type     type; };
+
+#if __cplusplus > 201103L
+  /// Alias template for remove_extent
+  template<typename _Tp>
+    using remove_extent_t = typename remove_extent<_Tp>::type;
+
+  /// Alias template for remove_all_extents
+  template<typename _Tp>
+    using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
+#endif
+
+  // Pointer modifications.
+
+  template<typename _Tp, typename>
+    struct __remove_pointer_helper
+    { typedef _Tp     type; };
+
+  template<typename _Tp, typename _Up>
+    struct __remove_pointer_helper<_Tp, _Up*>
+    { typedef _Up     type; };
+
+  /// remove_pointer
+  template<typename _Tp>
+    struct remove_pointer
+    : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
+    { };
+
+  /// add_pointer
+  template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
+				      is_void<_Tp>>::value>
+    struct __add_pointer_helper
+    { typedef _Tp     type; };
+
+  template<typename _Tp>
+    struct __add_pointer_helper<_Tp, true>
+    { typedef typename remove_reference<_Tp>::type*     type; };
+
+  template<typename _Tp>
+    struct add_pointer 
+    : public __add_pointer_helper<_Tp>
+    { };
+
+#if __cplusplus > 201103L
+  /// Alias template for remove_pointer
+  template<typename _Tp>
+    using remove_pointer_t = typename remove_pointer<_Tp>::type;
+
+  /// Alias template for add_pointer
+  template<typename _Tp>
+    using add_pointer_t = typename add_pointer<_Tp>::type;
+#endif
+
+  template<std::size_t _Len>
+    struct __aligned_storage_msa
+    { 
+      union __type
+      {
+	unsigned char __data[_Len];
+	struct __attribute__((__aligned__)) { } __align; 
+      };
+    };
+
+  /**
+   *  @brief Alignment type.
+   *
+   *  The value of _Align is a default-alignment which shall be the
+   *  most stringent alignment requirement for any C++ object type
+   *  whose size is no greater than _Len (3.9). The member typedef
+   *  type shall be a POD type suitable for use as uninitialized
+   *  storage for any object whose size is at most _Len and whose
+   *  alignment is a divisor of _Align.
+  */
+  template<std::size_t _Len, std::size_t _Align =
+	   __alignof__(typename __aligned_storage_msa<_Len>::__type)>
+    struct aligned_storage
+    { 
+      union type
+      {
+	unsigned char __data[_Len];
+	struct __attribute__((__aligned__((_Align)))) { } __align; 
+      };
+    };
+
+
+  // Decay trait for arrays and functions, used for perfect forwarding
+  // in make_pair, make_tuple, etc.
+  template<typename _Up, 
+	   bool _IsArray = is_array<_Up>::value,
+	   bool _IsFunction = is_function<_Up>::value> 
+    struct __decay_selector;
+
+  // NB: DR 705.
+  template<typename _Up> 
+    struct __decay_selector<_Up, false, false>
+    { typedef typename remove_cv<_Up>::type __type; };
+
+  template<typename _Up> 
+    struct __decay_selector<_Up, true, false>
+    { typedef typename remove_extent<_Up>::type* __type; };
+
+  template<typename _Up> 
+    struct __decay_selector<_Up, false, true>
+    { typedef typename add_pointer<_Up>::type __type; };
+
+  /// decay
+  template<typename _Tp> 
+    class decay 
+    { 
+      typedef typename remove_reference<_Tp>::type __remove_type;
+
+    public:
+      typedef typename __decay_selector<__remove_type>::__type type;
+    };
+
+  template<typename _Tp>
+    class reference_wrapper;
+
+  // Helper which adds a reference to a type when given a reference_wrapper
+  template<typename _Tp>
+    struct __strip_reference_wrapper
+    {
+      typedef _Tp __type;
+    };
+
+  template<typename _Tp>
+    struct __strip_reference_wrapper<reference_wrapper<_Tp> >
+    {
+      typedef _Tp& __type;
+    };
+
+  template<typename _Tp>
+    struct __decay_and_strip
+    {
+      typedef typename __strip_reference_wrapper<
+	typename decay<_Tp>::type>::__type __type;
+    };
+
+
+  // Primary template.
+  /// Define a member typedef @c type only if a boolean constant is true.
+  template<bool, typename _Tp = void>
+    struct enable_if 
+    { };
+
+  // Partial specialization for true.
+  template<typename _Tp>
+    struct enable_if<true, _Tp>
+    { typedef _Tp type; };
+
+  template<typename... _Cond>
+    using _Require = typename enable_if<__and_<_Cond...>::value>::type;
+
+  // Primary template.
+  /// Define a member typedef @c type to one of two argument types.
+  template<bool _Cond, typename _Iftrue, typename _Iffalse>
+    struct conditional
+    { typedef _Iftrue type; };
+
+  // Partial specialization for false.
+  template<typename _Iftrue, typename _Iffalse>
+    struct conditional<false, _Iftrue, _Iffalse>
+    { typedef _Iffalse type; };
+
+  /// common_type
+  template<typename... _Tp>
+    struct common_type;
+
+  // Sfinae-friendly common_type implementation:
+
+  struct __do_common_type_impl
+  {
+    template<typename _Tp, typename _Up>
+      static __success_type<typename decay<decltype
+			    (true ? std::declval<_Tp>()
+			     : std::declval<_Up>())>::type> _S_test(int);
+
+    template<typename, typename>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _Tp, typename _Up>
+    struct __common_type_impl
+    : private __do_common_type_impl
+    {
+      typedef decltype(_S_test<_Tp, _Up>(0)) type;
+    };
+
+  struct __do_member_type_wrapper
+  {
+    template<typename _Tp>
+      static __success_type<typename _Tp::type> _S_test(int);
+
+    template<typename>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _Tp>
+    struct __member_type_wrapper
+    : private __do_member_type_wrapper
+    {
+      typedef decltype(_S_test<_Tp>(0)) type;
+    };
+
+  template<typename _CTp, typename... _Args>
+    struct __expanded_common_type_wrapper
+    {
+      typedef common_type<typename _CTp::type, _Args...> type;
+    };
+
+  template<typename... _Args>
+    struct __expanded_common_type_wrapper<__failure_type, _Args...>
+    { typedef __failure_type type; };
+
+  template<typename _Tp>
+    struct common_type<_Tp>
+    { typedef typename decay<_Tp>::type type; };
+
+  template<typename _Tp, typename _Up>
+    struct common_type<_Tp, _Up>
+    : public __common_type_impl<_Tp, _Up>::type
+    { };
+
+  template<typename _Tp, typename _Up, typename... _Vp>
+    struct common_type<_Tp, _Up, _Vp...>
+    : public __expanded_common_type_wrapper<typename __member_type_wrapper<
+               common_type<_Tp, _Up>>::type, _Vp...>::type
+    { };
+
+  /// The underlying type of an enum.
+  template<typename _Tp>
+    struct underlying_type
+    {
+      typedef __underlying_type(_Tp) type;
+    };
+
+  template<typename _Tp>
+    struct __declval_protector
+    {
+      static const bool __stop = false;
+      static typename add_rvalue_reference<_Tp>::type __delegate();
+    };
+
+  template<typename _Tp>
+    inline typename add_rvalue_reference<_Tp>::type
+    declval() noexcept
+    {
+      static_assert(__declval_protector<_Tp>::__stop,
+		    "declval() must not be used!");
+      return __declval_protector<_Tp>::__delegate();
+    }
+
+  /// result_of
+  template<typename _Signature>
+    class result_of;
+
+  // Sfinae-friendly result_of implementation:
+
+  // [func.require] paragraph 1 bullet 1:
+  struct __result_of_memfun_ref_impl
+  {
+    template<typename _Fp, typename _Tp1, typename... _Args>
+      static __success_type<decltype(
+      (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
+      )> _S_test(int);
+
+    template<typename...>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _MemPtr, typename _Arg, typename... _Args>
+    struct __result_of_memfun_ref
+    : private __result_of_memfun_ref_impl
+    {
+      typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
+    };
+
+  // [func.require] paragraph 1 bullet 2:
+  struct __result_of_memfun_deref_impl
+  {
+    template<typename _Fp, typename _Tp1, typename... _Args>
+      static __success_type<decltype(
+      ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
+      )> _S_test(int);
+
+    template<typename...>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _MemPtr, typename _Arg, typename... _Args>
+    struct __result_of_memfun_deref
+    : private __result_of_memfun_deref_impl
+    {
+      typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
+    };
+
+  // [func.require] paragraph 1 bullet 3:
+  struct __result_of_memobj_ref_impl
+  {
+    template<typename _Fp, typename _Tp1>
+      static __success_type<decltype(
+      std::declval<_Tp1>().*std::declval<_Fp>()
+      )> _S_test(int);
+
+    template<typename, typename>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _MemPtr, typename _Arg>
+    struct __result_of_memobj_ref
+    : private __result_of_memobj_ref_impl
+    {
+      typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
+    };
+
+  // [func.require] paragraph 1 bullet 4:
+  struct __result_of_memobj_deref_impl
+  {
+    template<typename _Fp, typename _Tp1>
+      static __success_type<decltype(
+      (*std::declval<_Tp1>()).*std::declval<_Fp>()
+      )> _S_test(int);
+
+    template<typename, typename>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _MemPtr, typename _Arg>
+    struct __result_of_memobj_deref
+    : private __result_of_memobj_deref_impl
+    {
+      typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
+    };
+
+  template<typename _MemPtr, typename _Arg>
+    struct __result_of_memobj;
+
+  template<typename _Res, typename _Class, typename _Arg>
+    struct __result_of_memobj<_Res _Class::*, _Arg>
+    {
+      typedef typename remove_cv<typename remove_reference<
+        _Arg>::type>::type _Argval;
+      typedef _Res _Class::* _MemPtr;
+      typedef typename conditional<__or_<is_same<_Argval, _Class>,
+        is_base_of<_Class, _Argval>>::value,
+        __result_of_memobj_ref<_MemPtr, _Arg>,
+        __result_of_memobj_deref<_MemPtr, _Arg>
+      >::type::type type;
+    };
+
+  template<typename _MemPtr, typename _Arg, typename... _Args>
+    struct __result_of_memfun;
+
+  template<typename _Res, typename _Class, typename _Arg, typename... _Args>
+    struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
+    {
+      typedef typename remove_cv<typename remove_reference<
+        _Arg>::type>::type _Argval;
+      typedef _Res _Class::* _MemPtr;
+      typedef typename conditional<__or_<is_same<_Argval, _Class>,
+        is_base_of<_Class, _Argval>>::value,
+        __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
+        __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
+      >::type::type type;
+    };
+
+  template<bool, bool, typename _Functor, typename... _ArgTypes>
+    struct __result_of_impl
+    {
+      typedef __failure_type type;
+    };
+
+  template<typename _MemPtr, typename _Arg>
+    struct __result_of_impl<true, false, _MemPtr, _Arg>
+    : public __result_of_memobj<typename decay<_MemPtr>::type, _Arg>
+    { };
+
+  template<typename _MemPtr, typename _Arg, typename... _Args>
+    struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
+    : public __result_of_memfun<typename decay<_MemPtr>::type, _Arg, _Args...>
+    { };
+
+  // [func.require] paragraph 1 bullet 5:
+  struct __result_of_other_impl
+  {
+    template<typename _Fn, typename... _Args>
+      static __success_type<decltype(
+      std::declval<_Fn>()(std::declval<_Args>()...)
+      )> _S_test(int);
+
+    template<typename...>
+      static __failure_type _S_test(...);
+  };
+
+  template<typename _Functor, typename... _ArgTypes>
+    struct __result_of_impl<false, false, _Functor, _ArgTypes...>
+    : private __result_of_other_impl
+    {
+      typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
+    };
+
+  template<typename _Functor, typename... _ArgTypes>
+    struct result_of<_Functor(_ArgTypes...)>
+    : public __result_of_impl<
+        is_member_object_pointer<
+          typename remove_reference<_Functor>::type
+        >::value,
+        is_member_function_pointer<
+          typename remove_reference<_Functor>::type
+        >::value,
+	    _Functor, _ArgTypes...
+      >::type
+    { };
+
+#if __cplusplus > 201103L
+  /// Alias template for aligned_storage
+  template<size_t _Len, size_t _Align =
+	    __alignof__(typename __aligned_storage_msa<_Len>::__type)>
+    using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
+
+  /// Alias template for decay
+  template<typename _Tp>
+    using decay_t = typename decay<_Tp>::type;
+
+  /// Alias template for enable_if
+  template<bool _Cond, typename _Tp = void>
+    using enable_if_t = typename enable_if<_Cond, _Tp>::type;
+
+  /// Alias template for conditional
+  template<bool _Cond, typename _Iftrue, typename _Iffalse>
+    using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
+
+  /// Alias template for common_type
+  template<typename... _Tp>
+    using common_type_t = typename common_type<_Tp...>::type;
+
+  /// Alias template for underlying_type
+  template<typename _Tp>
+    using underlying_type_t = typename underlying_type<_Tp>::type;
+
+  /// Alias template for result_of
+  template<typename _Tp>
+    using result_of_t = typename result_of<_Tp>::type;
+#endif
+
+  /// @} group metaprogramming
+	
+  /**
+   *  Use SFINAE to determine if the type _Tp has a publicly-accessible
+   *  member type _NTYPE.
+   */
+#define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE)				\
+  template<typename _Tp>						\
+    class __has_##_NTYPE##_helper					\
+    {									\
+      template<typename _Up>						\
+	struct _Wrap_type						\
+	{ };								\
+									\
+      template<typename _Up>						\
+	static true_type __test(_Wrap_type<typename _Up::_NTYPE>*);	\
+									\
+      template<typename _Up>						\
+	static false_type __test(...);					\
+									\
+    public:								\
+      typedef decltype(__test<_Tp>(0)) type;				\
+    };									\
+									\
+  template<typename _Tp>						\
+    struct __has_##_NTYPE						\
+    : public __has_##_NTYPE##_helper					\
+			<typename remove_cv<_Tp>::type>::type		\
+    { };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+
+#endif  // C++11
+
+#endif  // _GLIBCXX_TYPE_TRAITS