fix behavior

src/etc/gdb_rust_pretty_printing.py

@@ -308,13 +308,13 @@ class RustStdBTreeSetPrinter(object):
 
     @staticmethod
     def display_hint():
-        return "map"
+        return "array"
 
     def to_string(self):
         (length, data_ptr) = \
             rustpp.extract_length_and_ptr_from_std_btreeset(self.__val)
         return (self.__val.type.get_unqualified_type_name() +
-                (" with %i elements" % length))
+                ("(len: %i)" % length))
 
     def children(self):
         (length, data_ptr) = \
@@ -322,7 +322,6 @@ class RustStdBTreeSetPrinter(object):
         val = GdbValue(data_ptr.get_wrapped_value().dereference()).get_child_at_index(3)
         gdb_ptr = val.get_wrapped_value()
         for index in xrange(length):
-            yield (str(index), str(index))
             yield (str(index), gdb_ptr[index])
 
 

src/test/debuginfo/pretty-std-collections.rs

@@ -20,7 +20,7 @@
 // gdb-command: run
 
 // gdb-command: print btree_set
-// gdb-check:$1 = BTreeSet<i32> with 3 elements = {[0] = 3, [1] = 5, [2] = 7}
+// gdb-check:$1 = BTreeSet<i32>(len: 3) = {3, 5, 7}
 
 // gdb-command: print vec_deque
 // gdb-check:$2 = VecDeque<i32>(len: 3, cap: 8) = {5, 3, 7}