Re: [patch] Fix two libstdc++ test failures with -std=gnu++14

[François Dumont <frs dot dumont at gmail dot com>]

On 12/06/2015 01:22, Jonathan Wakely wrote:
> This fixes two test failures when the default compiler mode is
> -std=gnu++14
>
> FAIL: 25_algorithms/headers/algorithm/synopsis.cc (test for excess
> errors)
> FAIL: ext/profile/mutex_extensions_neg.cc (test for excess errors)
>
> I don't really like the change to the synopsis.cc test, but I don't
> think reproducing the SFINAE constraints in the test is ideal either.
>
> The mutex_extensions_neg.cc test works now, but I think we're missing
> specializations of __is_tuple_like_impl for __gnu_debug::array and
> __gnu_profile::array.
>
> Tested powerpc64le-linux, committed to trunk.
>
This patch introduced a regression in
20_util/tuple/creation_functions/tuple_cat.cc in debug mode.

Attached is a proposal to fix it properly. I am using <utility> as a
pivot header between <tuple> and <array>. This way <tuple> do not need
to include <array> anymore.

It also adds missing version namespace macro in debug and profile headers.

Not tested yet as I would like to know first if it ok to do it this way.

François

diff --git a/libstdc++-v3/include/debug/array b/libstdc++-v3/include/debug/array
index 34e6281..a1c7d40 100644
--- a/libstdc++-v3/include/debug/array
+++ b/libstdc++-v3/include/debug/array
@@ -31,6 +31,8 @@
 
 #pragma GCC system_header
 
+#include <array>
+
 #include <debug/formatter.h>
 #include <debug/macros.h>
 
@@ -292,20 +294,27 @@ namespace __debug
     }
 } // namespace __debug
 
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Tuple interface to class template array.
 
   /// tuple_size
   template<typename _Tp, std::size_t _Nm>
-    struct tuple_size<__debug::array<_Tp, _Nm>>
+    struct tuple_size<std::__debug::array<_Tp, _Nm>>
     : public integral_constant<std::size_t, _Nm> { };
 
   /// tuple_element
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
-    struct tuple_element<_Int, __debug::array<_Tp, _Nm>>
+    struct tuple_element<_Int, std::__debug::array<_Tp, _Nm>>
     {
       static_assert(_Int < _Nm, "index is out of bounds");
       typedef _Tp type;
     };
+
+  template<typename _Tp, std::size_t _Nm>
+    struct __is_tuple_like_impl<std::__debug::array<_Tp, _Nm>> : true_type
+    { };
+
+_GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
 #endif // _GLIBCXX_DEBUG_ARRAY
diff --git a/libstdc++-v3/include/profile/array b/libstdc++-v3/include/profile/array
index 434ca96..687c052 100644
--- a/libstdc++-v3/include/profile/array
+++ b/libstdc++-v3/include/profile/array
@@ -31,6 +31,8 @@
 
 #pragma GCC system_header
 
+#include <array>
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 namespace __profile
@@ -253,20 +255,27 @@ namespace __profile
     }
 } // namespace __profile
 
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Tuple interface to class template array.
 
   /// tuple_size
   template<typename _Tp, std::size_t _Nm>
-    struct tuple_size<__profile::array<_Tp, _Nm>>
+    struct tuple_size<std::__profile::array<_Tp, _Nm>>
     : public integral_constant<std::size_t, _Nm> { };
 
   /// tuple_element
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
-    struct tuple_element<_Int, __profile::array<_Tp, _Nm>>
+    struct tuple_element<_Int, std::__profile::array<_Tp, _Nm>>
     {
       static_assert(_Int < _Nm, "index is out of bounds");
       typedef _Tp type;
     };
+
+  template<typename _Tp, std::size_t _Nm>
+    struct __is_tuple_like_impl<std::__profile::array<_Tp, _Nm>> : true_type
+    { };
+
+_GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
 #endif // _GLIBCXX_PROFILE_ARRAY
diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array
index 40fbd46..d1b5e6d 100644
--- a/libstdc++-v3/include/std/array
+++ b/libstdc++-v3/include/std/array
@@ -35,6 +35,7 @@
 # include <bits/c++0x_warning.h>
 #else
 
+#include <utility>
 #include <stdexcept>
 #include <bits/stl_algobase.h>
 #include <bits/range_access.h>
@@ -331,6 +332,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       typedef _Tp type;
     };
 
+  template<typename _Tp, std::size_t _Nm>
+    struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
+    { };
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index ccea02b..cd10474 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -36,7 +36,7 @@
 #else
 
 #include <utility>
-#include <array>
+
 #include <bits/uses_allocator.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
@@ -976,22 +976,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     forward_as_tuple(_Elements&&... __args) noexcept
     { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); }
 
-  template<typename>
-    struct __is_tuple_like_impl : false_type
-    { };
-
   template<typename... _Tps>
     struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
     { };
 
-  template<typename _T1, typename _T2>
-    struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type
-    { };
-
-  template<typename _Tp, std::size_t _Nm>
-    struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type
-    { };
-
   // Internal type trait that allows us to sfinae-protect tuple_cat.
   template<typename _Tp>
     struct __is_tuple_like
diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility
index 1aac77c..88a6079 100644
--- a/libstdc++-v3/include/std/utility
+++ b/libstdc++-v3/include/std/utility
@@ -71,6 +71,7 @@
 
 #if __cplusplus >= 201103L
 
+#include <type_traits>
 #include <bits/move.h>
 #include <initializer_list>
 
@@ -84,7 +85,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<std::size_t _Int, class _Tp>
     class tuple_element;
 
-   // Various functions which give std::pair a tuple-like interface.
+  template<typename>
+    struct __is_tuple_like_impl : false_type
+    { };
+
+  template<typename _T1, typename _T2>
+    struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type
+    { };
+
+  // Various functions which give std::pair a tuple-like interface.
 
   /// Partial specialization for std::pair
   template<class _Tp1, class _Tp2>