PR c++/78898 - ICE on constructor with TTP

	PR c++/42329
	* pt.c (unify): Don't look for a class template from a non-class.

From-SVN: r243890

gcc/cp/ChangeLog

+2016-12-22  Jason Merrill  <jason@redhat.com>
+
+	PR c++/78898
+	PR c++/42329
+	* pt.c (unify): Don't look for a class template from a non-class.
+
 2016-12-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/72707

gcc/cp/pt.c

@@ -20292,7 +20292,8 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
 
       if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
 	{
-	  if (strict_in & UNIFY_ALLOW_DERIVED)
+	  if ((strict_in & UNIFY_ALLOW_DERIVED)
+	      && CLASS_TYPE_P (arg))
 	    {
 	      /* First try to match ARG directly.  */
 	      tree t = try_class_unification (tparms, targs, parm, arg,

gcc/testsuite/g++.dg/template/ttp30.C

+// PR c++/78898
+
+struct A {
+  template <class T> A(T);
+  template <template <typename> class SmartPtr> A(SmartPtr<int>) { A(0); }
+};