re PR libstdc++/64695 (FAIL: libstdc++-prettyprinters/cxx11.cc)

	PR libstdc++/64695
	* python/libstdcxx/v6/printers.py (StdTuplePrinter): Handle new
	tuple layout.

From-SVN: r220871

libstdc++-v3/ChangeLog

+2015-02-20  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/64695
+	* python/libstdcxx/v6/printers.py (StdTuplePrinter): Handle new
+	tuple layout.
+
 2015-02-19  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/58357

libstdc++-v3/python/libstdcxx/v6/printers.py

@@ -327,14 +327,26 @@ class StdTuplePrinter:
             return self
 
         def __next__ (self):
-            nodes = self.head.type.fields ()
             # Check for further recursions in the inheritance tree.
+            # For a GCC 5+ tuple self.head is None after visiting all nodes:
+            if not self.head:
+                raise StopIteration
+            nodes = self.head.type.fields ()
+            # For a GCC 4.x tuple there is a final node with no fields:
             if len (nodes) == 0:
                 raise StopIteration
             # Check that this iteration has an expected structure.
-            if len (nodes) != 2:
+            if len (nodes) > 2:
                 raise ValueError("Cannot parse more than 2 nodes in a tuple tree.")
 
+            if len (nodes) == 1:
+                # This is the last node of a GCC 5+ std::tuple.
+                impl = self.head.cast (nodes[0].type)
+                self.head = None
+            else:
+                # Either a node before the last node, or the last node of
+                # a GCC 4.x tuple (which has an empty parent).
+
                 # - Left node is the next recursion parent.
                 # - Right node is the actual class contained in the tuple.
 
@@ -343,6 +355,7 @@ class StdTuplePrinter:
 
                 # Process left node and set it as head.
                 self.head  = self.head.cast (nodes[0].type)
+
             self.count = self.count + 1
 
             # Finally, check the implementation.  If it is