diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index 1ee8ddc..c797246 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -644,7 +644,10 @@ experimental_headers = \
${experimental_srcdir}/string_view \
${experimental_srcdir}/string_view.tcc \
${experimental_srcdir}/tuple \
- ${experimental_srcdir}/type_traits
+ ${experimental_srcdir}/type_traits \
+ ${experimental_srcdir}/ratio \
+ ${experimental_srcdir}/chrono \
+ ${experimental_srcdir}/system_error \
# This is the common subset of C++ files that all three "C" header models use.
c_base_srcdir = $(C_INCLUDE_DIR)
diff --git a/libstdc++-v3/include/experimental/chrono b/libstdc++-v3/include/experimental/chrono
new file mode 100644
index 0000000..d817f45
--- /dev/null
+++ b/libstdc++-v3/include/experimental/chrono
@@ -0,0 +1,65 @@
+// Variable Templates For chrono -*- C++ -*-
+
+// Copyright (C) 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
+// .
+
+/** @file experimental/chrono
+ * This is a TS C++ Library header.
+ */
+
+//
+// N3932 Variable Templates For Type Traits (Revision 1)
+//
+
+#ifndef _GLIBCXX_EXPERIMENTAL_CHRONO
+#define _GLIBCXX_EXPERIMENTAL_CHRONO 1
+
+#pragma GCC system_header
+
+#if __cplusplus <= 201103L
+# include
+#else
+
+#include
+
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+namespace chrono {
+namespace experimental
+{
+inline namespace fundamentals_v1
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+// See C++14 §20.12.4, customization traits
+template
+ constexpr bool treat_as_floating_point_v =
+ treat_as_floating_point<_Rep>::value;
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace chrono
+} // namespace std
+
+#endif // __cplusplus <= 201103L
+
+#endif // _GLIBCXX_EXPERIMENTAL_CHRONO
diff --git a/libstdc++-v3/include/experimental/ratio b/libstdc++-v3/include/experimental/ratio
new file mode 100644
index 0000000..dbbe33f
--- /dev/null
+++ b/libstdc++-v3/include/experimental/ratio
@@ -0,0 +1,73 @@
+// Variable Templates For ratio -*- C++ -*-
+
+// Copyright (C) 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
+// .
+
+/** @file experimental/ratio
+ * This is a TS C++ Library header.
+ */
+
+//
+// N3932 Variable Templates For Type Traits (Revision 1)
+//
+
+#ifndef _GLIBCXX_EXPERIMENTAL_RATIO
+#define _GLIBCXX_EXPERIMENTAL_RATIO 1
+
+#pragma GCC system_header
+
+#if __cplusplus <= 201103L
+# include
+#else
+
+#include
+
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+namespace experimental
+{
+inline namespace fundamentals_v1
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+// See C++14 §20.11.5, ratio comparison
+template
+ constexpr bool ratio_equal_v = ratio_equal<_R1, _R2>::value;
+template
+ constexpr bool ratio_not_equal_v = ratio_not_equal<_R1, _R2>::value;
+template
+ constexpr bool ratio_less_v = ratio_less<_R1, _R2>::value;
+template
+ constexpr bool ratio_less_equal_v = ratio_less_equal<_R1, _R2>::value;
+template
+ constexpr bool ratio_greater_v = ratio_greater<_R1, _R2>::value;
+template
+ constexpr bool ratio_greater_equal_v = ratio_greater_equal<_R1, _R2>::value;
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+#endif // __cplusplus <= 201103L
+
+#endif // _GLIBCXX_EXPERIMENTAL_RATIO
diff --git a/libstdc++-v3/include/experimental/system_error b/libstdc++-v3/include/experimental/system_error
new file mode 100644
index 0000000..50a5e72
--- /dev/null
+++ b/libstdc++-v3/include/experimental/system_error
@@ -0,0 +1,65 @@
+// Variable Templates For system_error -*- C++ -*-
+
+// Copyright (C) 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
+// .
+
+/** @file experimental/system_error
+ * This is a TS C++ Library header.
+ */
+
+//
+// N3932 Variable Templates For Type Traits (Revision 1)
+//
+
+#ifndef _GLIBCXX_EXPERIMENTAL_SYSTEM_ERROR
+#define _GLIBCXX_EXPERIMENTAL_CHRONO 1
+
+#pragma GCC system_header
+
+#if __cplusplus <= 201103L
+# include
+#else
+
+#include
+
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+namespace experimental
+{
+inline namespace fundamentals_v1
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+// See C++14 §19.5, System error support
+template
+ constexpr bool is_error_code_enum_v = is_error_code_enum<_Tp>::value;
+template
+ constexpr bool is_error_condition_enum_v =
+ is_error_condition_enum<_Tp>::value;
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+#endif // __cplusplus <= 201103L
+
+#endif // _GLIBCXX_EXPERIMENTAL_SYSTEM_ERROR
diff --git a/libstdc++-v3/include/experimental/tuple b/libstdc++-v3/include/experimental/tuple
index bbfbdfa..5794e91 100644
--- a/libstdc++-v3/include/experimental/tuple
+++ b/libstdc++-v3/include/experimental/tuple
@@ -44,6 +44,9 @@ namespace experimental
inline namespace fundamentals_v1
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
+ // See C++14 §20.4.2.5, tuple helper classes
+ template
+ constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
template
constexpr decltype(auto)
diff --git a/libstdc++-v3/testsuite/experimental/chrono/value.cc b/libstdc++-v3/testsuite/experimental/chrono/value.cc
new file mode 100644
index 0000000..c06c12a
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/chrono/value.cc
@@ -0,0 +1,34 @@
+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 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.
+
+// You should have received a moved_to of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// .
+
+#include
+
+using namespace std::chrono;
+using namespace std::chrono::experimental;
+
+// 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
+ && !treat_as_floating_point::value, "");
+
+static_assert(treat_as_floating_point_v
+ && treat_as_floating_point::value, "");
diff --git a/libstdc++-v3/testsuite/experimental/ratio/value.cc b/libstdc++-v3/testsuite/experimental/ratio/value.cc
new file mode 100644
index 0000000..4c8bdd7
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/ratio/value.cc
@@ -0,0 +1,50 @@
+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 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.
+
+// You should have received a moved_to of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// .
+
+#include
+
+using namespace std;
+using namespace std::experimental;
+
+// 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<2, 6>>
+ && ratio_equal, ratio<2, 6>>::value, "");
+
+static_assert(ratio_not_equal_v, ratio<2, 5>>
+ && ratio_not_equal, ratio<2, 5>>::value, "");
+
+static_assert(ratio_less_v, ratio<1, 3>>
+ && ratio_less, ratio<1, 3>>::value, "");
+
+static_assert(ratio_less_equal_v, ratio<1, 4>>
+ && ratio_less_equal_v, ratio<1, 3>>
+ && ratio_less_equal, ratio<1, 4>>::value
+ && ratio_less_equal, ratio<1, 3>>::value, "");
+
+static_assert(ratio_greater_v, ratio<1, 4>>
+ && ratio_greater, ratio<1, 4>>::value, "");
+
+static_assert(ratio_greater_equal_v, ratio<1, 4>>
+ && ratio_greater_equal_v, ratio<1, 4>>
+ && ratio_greater_equal, ratio<1, 4>>::value
+ && ratio_greater_equal, ratio<1, 4>>::value, "");
diff --git a/libstdc++-v3/testsuite/experimental/system_error/value.cc b/libstdc++-v3/testsuite/experimental/system_error/value.cc
new file mode 100644
index 0000000..66b40fb
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/system_error/value.cc
@@ -0,0 +1,40 @@
+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 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.
+
+// You should have received a moved_to of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// .
+
+#include
+#include
+using namespace std;
+using namespace std::experimental;
+
+// 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
+ && is_error_code_enum::value, "");
+
+static_assert(!is_error_code_enum_v
+ && !is_error_code_enum::value, "");
+
+static_assert(is_error_condition_enum_v
+ && is_error_condition_enum::value, "");
+
+static_assert(!is_error_condition_enum_v
+ && !is_error_condition_enum::value, "");
diff --git a/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc b/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc
new file mode 100644
index 0000000..604e2c9
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc
@@ -0,0 +1,34 @@
+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 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.
+
+// You should have received a moved_to of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// .
+
+#include
+
+using namespace std;
+using namespace std::experimental;
+
+// 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> == 1
+ && tuple_size>::value == 1, "");
+
+static_assert(tuple_size_v> == 2
+ && tuple_size>::value == 2, "");