Fix ambiguities in C++17 mode

commit d1eda6aaf0f7105277fa06368c5f9970df126154
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Aug 19 09:35:11 2016 +0100

    Fix ambiguities in C++17 mode
    
    	* include/experimental/tuple (apply): Qualify call to __apply_impl.
    	* include/std/tuple (apply): Likewise.
    	* testsuite/experimental/system_error/value.cc: Fix ambiguities in
    	C++17 mode.
    	* testsuite/experimental/tuple/tuple_size.cc: Likewise.
    	* testsuite/experimental/type_traits/value.cc: Likewise.

diff --git a/libstdc++-v3/include/experimental/tuple b/libstdc++-v3/include/experimental/tuple
index bfa1ed1..b653ea7 100644
--- a/libstdc++-v3/include/experimental/tuple
+++ b/libstdc++-v3/include/experimental/tuple
@@ -66,8 +66,9 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       using _Indices =
 	std::make_index_sequence<tuple_size_v<std::decay_t<_Tuple>>>;
-      return __apply_impl(std::forward<_Fn>(__f), std::forward<_Tuple>(__t),
-			  _Indices{});
+      return experimental::__apply_impl(std::forward<_Fn>(__f),
+					std::forward<_Tuple>(__t),
+					_Indices{});
     }
 
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index 29db833..c06a040 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -1652,8 +1652,9 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     apply(_Fn&& __f, _Tuple&& __t)
     {
       using _Indices = make_index_sequence<tuple_size_v<decay_t<_Tuple>>>;
-      return __apply_impl(std::forward<_Fn>(__f), std::forward<_Tuple>(__t),
-			  _Indices{});
+      return std::__apply_impl(std::forward<_Fn>(__f),
+			       std::forward<_Tuple>(__t),
+			       _Indices{});
     }
 
 #define __cpp_lib_make_from_tuple  201606
diff --git a/libstdc++-v3/testsuite/experimental/system_error/value.cc b/libstdc++-v3/testsuite/experimental/system_error/value.cc
index ee792cb..3b346ce 100644
--- a/libstdc++-v3/testsuite/experimental/system_error/value.cc
+++ b/libstdc++-v3/testsuite/experimental/system_error/value.cc
@@ -20,21 +20,23 @@ 
 
 #include <experimental/system_error>
 #include <future>
-using namespace std;
-using namespace std::experimental;
+using std::is_error_code_enum;
+using std::is_error_condition_enum;
+using std::experimental::is_error_code_enum_v;
+using std::experimental::is_error_condition_enum_v;
 
 // These tests are rather simple, the front-end tests already test
 // variable templates, and the library tests for the underlying
 // traits are more elaborate. These are just simple sanity tests.
 
-static_assert(is_error_code_enum_v<future_errc>
-	      && is_error_code_enum<future_errc>::value, "");
+static_assert(is_error_code_enum_v<std::future_errc>
+	      && is_error_code_enum<std::future_errc>::value, "");
 
 static_assert(!is_error_code_enum_v<int>
 	      && !is_error_code_enum<int>::value, "");
 
-static_assert(is_error_condition_enum_v<errc>
-	      && is_error_condition_enum<errc>::value, "");
+static_assert(is_error_condition_enum_v<std::errc>
+	      && is_error_condition_enum<std::errc>::value, "");
 
 static_assert(!is_error_condition_enum_v<int>
 	      && !is_error_condition_enum<int>::value, "");
diff --git a/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc b/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc
index 953d3b2..e9a49ea 100644
--- a/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc
+++ b/libstdc++-v3/testsuite/experimental/tuple/tuple_size.cc
@@ -20,8 +20,9 @@ 
 
 #include <experimental/tuple>
 
-using namespace std;
-using namespace std::experimental;
+using std::tuple;
+using std::tuple_size;
+using std::experimental::tuple_size_v;
 
 // These tests are rather simple, the front-end tests already test
 // variable templates, and the library tests for the underlying
diff --git a/libstdc++-v3/testsuite/experimental/type_traits/value.cc b/libstdc++-v3/testsuite/experimental/type_traits/value.cc
index 16b63cb..6a7a95d 100644
--- a/libstdc++-v3/testsuite/experimental/type_traits/value.cc
+++ b/libstdc++-v3/testsuite/experimental/type_traits/value.cc
@@ -20,8 +20,74 @@ 
 
 #include <experimental/type_traits>
 
-using namespace std;
-using namespace experimental;
+using std::true_type;
+using std::false_type;
+using std::nullptr_t;
+using std::is_void;
+using std::is_null_pointer;
+using std::is_integral;
+using std::is_floating_point;
+using std::is_array;
+using std::is_pointer;
+using std::is_lvalue_reference;
+using std::is_rvalue_reference;
+using std::is_member_object_pointer;
+using std::is_member_function_pointer;
+using std::is_enum;
+using std::is_union;
+using std::is_class;
+using std::is_function;
+using std::is_reference;
+using std::is_arithmetic;
+using std::is_fundamental;
+using std::is_object;
+using std::is_scalar;
+using std::is_compound;
+using std::is_member_pointer;
+using std::is_const;
+using std::is_volatile;
+using std::is_trivial;
+using std::is_trivially_copyable;
+using std::is_standard_layout;
+using std::is_pod;
+using std::is_literal_type;
+using std::is_empty;
+using std::is_polymorphic;
+using std::is_abstract;
+using std::is_final;
+using std::is_signed;
+using std::is_constructible;
+using std::is_default_constructible;
+using std::is_copy_constructible;
+using std::is_move_constructible;
+using std::is_assignable;
+using std::is_copy_assignable;
+using std::is_move_assignable;
+using std::is_destructible;
+using std::is_trivially_constructible;
+using std::is_trivially_default_constructible;
+using std::is_trivially_copy_constructible;
+using std::is_trivially_move_constructible;
+using std::is_trivially_assignable;
+using std::is_trivially_copy_assignable;
+using std::is_trivially_move_assignable;
+using std::is_trivially_destructible;
+using std::is_nothrow_constructible;
+using std::is_nothrow_default_constructible;
+using std::is_nothrow_copy_constructible;
+using std::is_nothrow_move_constructible;
+using std::is_nothrow_assignable;
+using std::is_nothrow_copy_assignable;
+using std::is_nothrow_move_assignable;
+using std::is_nothrow_destructible;
+using std::has_virtual_destructor;
+using std::alignment_of;
+using std::rank;
+using std::extent;
+using std::is_same;
+using std::is_base_of;
+using std::is_convertible;
+using namespace std::experimental;
 
 // These tests are rather simple, the front-end tests already test
 // variable templates, and the library tests for the underlying