diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 6d78dd2..62fa2d9 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -130,6 +130,8 @@ static tree tsubst_initializer_list (tree, tree);
 static tree get_class_bindings (tree, tree, tree, tree);
 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
 				   bool, bool);
+static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
+					      bool, bool);
 static void tsubst_enum	(tree, tree, tree);
 static tree add_to_template_args (tree, tree);
 static tree add_outermost_template_args (tree, tree);
@@ -6742,6 +6744,61 @@ coerce_template_parms (tree parms,
   return new_inner_args;
 }
 
+/* Like coerce_template_parms.  If PARMS represents all template
+   parameters levels, this function returns a vector of vectors
+   representing all the resulting argument levels.  Note that in this
+   case, only the innermost arguments are coerced because the
+   outermost ones are supposed to have been coerced already.
+
+   Otherwise, if PARMS represents only (the innermost) vector of
+   parameters, this function returns a vector containing just the
+   innermost resulting arguments.  */
+
+static tree
+coerce_innermost_template_parms (tree parms,
+				  tree args,
+				  tree in_decl,
+				  tsubst_flags_t complain,
+				  bool require_all_args,
+				  bool use_default_args)
+{
+  int parms_depth = TMPL_PARMS_DEPTH (parms);
+  int args_depth = TMPL_ARGS_DEPTH (args);
+  tree coerced_args;
+
+  if (parms_depth > 1)
+    {
+      coerced_args = make_tree_vec (parms_depth);
+      tree level;
+      int cur_depth;
+
+      for (level = parms, cur_depth = parms_depth;
+	   parms_depth > 0 && level != NULL_TREE;
+	   level = TREE_CHAIN (level), --cur_depth)
+	{
+	  tree l;
+	  if (cur_depth == args_depth)
+	    l = coerce_template_parms (TREE_VALUE (level),
+				       args, in_decl, complain,
+				       require_all_args,
+				       use_default_args);
+	  else
+	    l = TMPL_ARGS_LEVEL (args, cur_depth);
+
+	  if (l == error_mark_node)
+	    return error_mark_node;
+
+	  SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
+	}
+    }
+  else
+    coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
+					  args, in_decl, complain,
+					  require_all_args,
+					  use_default_args);
+  return coerced_args;
+}
+
 /* Returns 1 if template args OT and NT are equivalent.  */
 
 static int
@@ -14642,6 +14699,13 @@ instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain)
       ggc_free (tinst);
       return error_mark_node;
     }
+
+  args =
+    coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
+				     args, tmpl, complain,
+				     /*require_all_args=*/true,
+				     /*use_default_args=*/true);
+
   tree r = instantiate_template (tmpl, args, complain);
   pop_tinst_level ();
   /* We can't free this if a pending_template entry or last_error_tinst_level
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-31.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-31.C
new file mode 100644
index 0000000..83eea47
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-31.C
@@ -0,0 +1,20 @@
+// Origin: PR c++/55663
+// { dg-do compile { target c++11 } }
+
+template <typename>
+constexpr bool the_truth () { return true; }
+
+template <bool>
+  struct Takes_bool { };
+
+template<bool B>
+  using Alias = Takes_bool<B>;
+
+template<typename T>
+  struct test { using type = Alias<the_truth<T>()>; };
+
+int main () {
+  test<int> a;
+
+  return 0;
+}
-- 
1.7.11.7


gcc/cp/

	* pt.c (lookup_template_class_1): Use coerce_inner_template_parms
	here for the sake of ease of maintenance.
---
 gcc/cp/pt.c | 65 ++++++++-----------------------------------------------------
 1 file changed, 8 insertions(+), 57 deletions(-)

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 62fa2d9..3c63407 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -7226,63 +7226,14 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
       /* From here on, we're only interested in the most general
 	 template.  */
 
-      /* Calculate the BOUND_ARGS.  These will be the args that are
-	 actually tsubst'd into the definition to create the
-	 instantiation.  */
-      if (parm_depth > 1)
-	{
-	  /* We have multiple levels of arguments to coerce, at once.  */
-	  int i;
-	  int saved_depth = TMPL_ARGS_DEPTH (arglist);
-
-	  tree bound_args = make_tree_vec (parm_depth);
-
-	  for (i = saved_depth,
-		 t = DECL_TEMPLATE_PARMS (gen_tmpl);
-	       i > 0 && t != NULL_TREE;
-	       --i, t = TREE_CHAIN (t))
-	    {
-	      tree a;
-	      if (i == saved_depth)
-		a = coerce_template_parms (TREE_VALUE (t),
-					   arglist, gen_tmpl,
-					   complain,
-					   /*require_all_args=*/true,
-					   /*use_default_args=*/true);
-	      else
-		/* Outer levels should have already been coerced.  */
-		a = TMPL_ARGS_LEVEL (arglist, i);
-
-	      /* Don't process further if one of the levels fails.  */
-	      if (a == error_mark_node)
-		{
-		  /* Restore the ARGLIST to its full size.  */
-		  TREE_VEC_LENGTH (arglist) = saved_depth;
-		  return error_mark_node;
-		}
-
-	      SET_TMPL_ARGS_LEVEL (bound_args, i, a);
-
-	      /* We temporarily reduce the length of the ARGLIST so
-		 that coerce_template_parms will see only the arguments
-		 corresponding to the template parameters it is
-		 examining.  */
-	      TREE_VEC_LENGTH (arglist)--;
-	    }
-
-	  /* Restore the ARGLIST to its full size.  */
-	  TREE_VEC_LENGTH (arglist) = saved_depth;
-
-	  arglist = bound_args;
-	}
-      else
-	arglist
-	  = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
-				   INNERMOST_TEMPLATE_ARGS (arglist),
-				   gen_tmpl,
-				   complain,
-				   /*require_all_args=*/true,
-				   /*use_default_args=*/true);
+      /* Convert the innermost template arguments to their appropriate
+	 types.  These will be the arguments that are actually
+	 tsubst'd into the definition to create the instantiation.  */
+      arglist =
+	coerce_innermost_template_parms (parmlist, arglist,
+					 gen_tmpl, complain,
+					 /*require_all_args=*/true,
+					 /*use_default_args=*/true);
 
       if (arglist == error_mark_node)
 	/* We were unable to bind the arguments.  */
