d: Use new isTypeXxxx helpers where possible.

gcc/d/ChangeLog:

	* d-builtins.cc (d_eval_constant_expression): Use isTypeXxxx helpers
	instead of explicit casts.
	(d_build_builtins_module): Likewise.
	* d-codegen.cc (get_array_length): Likewise.
	(identity_compare_p): Likewise.
	(lower_struct_comparison): Likewise.
	(build_array_from_val): Likewise.
	(array_bounds_check): Likewise.
	(get_function_type): Likewise.
	(d_build_call): Likewise.
	* d-compiler.cc (Compiler::paintAsType): Likewise.
	* d-convert.cc (convert_expr): Likewise.
	(convert_for_assignment): Likewise.
	* d-lang.cc (d_classify_record): Likewise.
	(d_build_eh_runtime_type): Likewise.
	* decl.cc (DeclVisitor::visit): Likewise.
	* expr.cc (ExprVisitor::needs_postblit): Likewise.
	(ExprVisitor::needs_dtor): Likewise.
	(ExprVisitor::visit): Likewise.
	* imports.cc (ImportVisitor::visit): Likewise.
	* typeinfo.cc (get_typeinfo_kind): Likewise.
	(TypeInfoVisitor::visit): Likewise.
	(TypeDeclInfoVisitor::visit): Likewise.
	* types.cc (merge_aggregate_types): Likewise.
	(TypeVisitor::visit): Likewise.

10 files changed, 82 insertions, 120 deletions

diff --git a/gcc/d/d-builtins.cc b/gcc/d/d-builtins.cc
index 91e3173..f1bdcb9 100644
--- a/gcc/d/d-builtins.cc
+++ b/gcc/d/d-builtins.cc
@@ -388,7 +388,7 @@ d_eval_constant_expression (tree cst)
 	    }
 
 	  Expression *e = ArrayLiteralExp::create (Loc (), elements);
-	  e->type = ((TypeVector *) type)->basetype;
+	  e->type = type->isTypeVector ()->basetype;
 
 	  return VectorExp::create (Loc (), e, type);
 	}
@@ -517,8 +517,8 @@ d_build_builtins_module (Module *m)
   for (size_t i = 0; vec_safe_iterate (gcc_builtins_functions, i, &decl); ++i)
     {
       const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
-      TypeFunction *tf
-	= (TypeFunction *) build_frontend_type (TREE_TYPE (decl));
+      Type *t = build_frontend_type (TREE_TYPE (decl));
+      TypeFunction *tf = t ? t->isTypeFunction () : NULL;
 
       /* Cannot create built-in function type for DECL.  */
       if (!tf)
@@ -601,14 +601,13 @@ d_build_builtins_module (Module *m)
 
   /* Expose target-specific va_list type.  */
   Type *tvalist = target.va_listType (Loc (), NULL);
-  StructDeclaration *sd = (tvalist->ty == Tstruct)
-    ? ((TypeStruct *) tvalist)->sym : NULL;
-  if (sd == NULL || !sd->isAnonymous ())
+  TypeStruct *ts = tvalist->isTypeStruct ();
+  if (ts == NULL || !ts->sym->isAnonymous ())
     members->push (build_alias_declaration ("__builtin_va_list", tvalist));
   else
     {
-      sd->ident = Identifier::idPool ("__builtin_va_list");
-      members->push (sd);
+      ts->sym->ident = Identifier::idPool ("__builtin_va_list");
+      members->push (ts->sym);
     }
 
   /* Expose target-specific integer types to the builtins module.  */
diff --git a/gcc/d/d-codegen.cc b/gcc/d/d-codegen.cc
index 83e757d..1bf74e1 100644
--- a/gcc/d/d-codegen.cc
+++ b/gcc/d/d-codegen.cc
@@ -319,7 +319,7 @@ get_array_length (tree exp, Type *type)
   switch (tb->ty)
     {
     case Tsarray:
-      return size_int (((TypeSArray *) tb)->dim->toUInteger ());
+      return size_int (tb->isTypeSArray ()->dim->toUInteger ());
 
     case Tarray:
       return d_array_length (exp);
@@ -812,9 +812,8 @@ identity_compare_p (StructDeclaration *sd)
       Type *tb = vd->type->toBasetype ();
 
       /* Check inner data structures.  */
-      if (tb->ty == Tstruct)
+      if (TypeStruct *ts = tb->isTypeStruct ())
 	{
-	  TypeStruct *ts = (TypeStruct *) tb;
 	  if (!identity_compare_p (ts->sym))
 	    return false;
 	}
@@ -897,11 +896,10 @@ lower_struct_comparison (tree_code code, StructDeclaration *sd,
       tree t2ref = component_ref (t2, sfield);
       tree tcmp;
 
-      if (type->ty == Tstruct)
+      if (TypeStruct *ts = type->isTypeStruct ())
 	{
 	  /* Compare inner data structures.  */
-	  StructDeclaration *decl = ((TypeStruct *) type)->sym;
-	  tcmp = lower_struct_comparison (code, decl, t1ref, t2ref);
+	  tcmp = lower_struct_comparison (code, ts->sym, t1ref, t2ref);
 	}
       else if (type->ty != Tvector && type->isintegral ())
 	{
@@ -1680,15 +1678,13 @@ build_array_set (tree ptr, tree length, tree value)
 tree
 build_array_from_val (Type *type, tree val)
 {
-  gcc_assert (type->ty == Tsarray);
-
   tree etype = build_ctype (type->nextOf ());
 
   /* Initializing a multidimensional array.  */
   if (TREE_CODE (etype) == ARRAY_TYPE && TREE_TYPE (val) != etype)
     val = build_array_from_val (type->nextOf (), val);
 
-  size_t dims = ((TypeSArray *) type)->dim->toInteger ();
+  size_t dims = type->isTypeSArray ()->dim->toInteger ();
   vec<constructor_elt, va_gc> *elms = NULL;
   vec_safe_reserve (elms, dims);
 
@@ -1762,8 +1758,7 @@ array_bounds_check (void)
       fd = d_function_chain->function;
       if (fd && fd->type->ty == Tfunction)
 	{
-	  TypeFunction *tf = (TypeFunction *) fd->type;
-	  if (tf->trust == TRUSTsafe)
+	  if (fd->type->isTypeFunction ()->trust == TRUSTsafe)
 	    return true;
 	}
       return false;
@@ -1783,9 +1778,9 @@ get_function_type (Type *t)
   if (t->ty == Tpointer)
     t = t->nextOf ()->toBasetype ();
   if (t->ty == Tfunction)
-    tf = (TypeFunction *) t;
+    tf = t->isTypeFunction ();
   else if (t->ty == Tdelegate)
-    tf = (TypeFunction *) ((TypeDelegate *) t)->next;
+    tf = t->isTypeDelegate ()->next->isTypeFunction ();
   return tf;
 }
 
@@ -1916,8 +1911,7 @@ d_build_call (TypeFunction *tf, tree callable, tree object,
 	  if (TREE_ADDRESSABLE (TREE_TYPE (targ)))
 	    {
 	      Type *t = arg->type->toBasetype ();
-	      gcc_assert (t->ty == Tstruct);
-	      StructDeclaration *sd = ((TypeStruct *) t)->sym;
+	      StructDeclaration *sd = t->isTypeStruct ()->sym;
 
 	      /* Nested structs also have ADDRESSABLE set, but if the type has
 		 neither a copy constructor nor a destructor available, then we
diff --git a/gcc/d/d-compiler.cc b/gcc/d/d-compiler.cc
index a8adb98..75ca157 100644
--- a/gcc/d/d-compiler.cc
+++ b/gcc/d/d-compiler.cc
@@ -111,7 +111,7 @@ Compiler::paintAsType (UnionExp *, Expression *expr, Type *type)
 	}
 
       /* Build vector type.  */
-      int nunits = ((TypeSArray *) expr->type)->dim->toUInteger ();
+      int nunits = expr->type->isTypeSArray ()->dim->toUInteger ();
       Type *telem = expr->type->nextOf ();
       tree vectype = build_vector_type (build_ctype (telem), nunits);
 
@@ -127,7 +127,7 @@ Compiler::paintAsType (UnionExp *, Expression *expr, Type *type)
     {
       /* Interpret value as a vector of the same size,
 	 then return the array literal.  */
-      int nunits = ((TypeSArray *) type)->dim->toUInteger ();
+      int nunits = type->isTypeSArray ()->dim->toUInteger ();
       Type *elem = type->nextOf ();
       tree vectype = build_vector_type (build_ctype (elem), nunits);
 
diff --git a/gcc/d/d-convert.cc b/gcc/d/d-convert.cc
index f93405e..80101f1 100644
--- a/gcc/d/d-convert.cc
+++ b/gcc/d/d-convert.cc
@@ -467,7 +467,7 @@ convert_expr (tree exp, Type *etype, Type *totype)
 	}
       else if (tbtype->ty == Tarray)
 	{
-	  dinteger_t dim = ((TypeSArray *) ebtype)->dim->toInteger ();
+	  dinteger_t dim = ebtype->isTypeSArray ()->dim->toInteger ();
 	  dinteger_t esize = ebtype->nextOf ()->size ();
 	  dinteger_t tsize = tbtype->nextOf ()->size ();
 
@@ -616,7 +616,7 @@ convert_for_assignment (tree expr, Type *etype, Type *totype)
 
       if (same_type_p (telem, ebtype))
 	{
-	  TypeSArray *sa_type = (TypeSArray *) tbtype;
+	  TypeSArray *sa_type = tbtype->isTypeSArray ();
 	  uinteger_t count = sa_type->dim->toUInteger ();
 
 	  tree ctor = build_constructor (build_ctype (totype), NULL);
diff --git a/gcc/d/d-lang.cc b/gcc/d/d-lang.cc
index badd67f..5266a65 100644
--- a/gcc/d/d-lang.cc
+++ b/gcc/d/d-lang.cc
@@ -1672,11 +1672,10 @@ static classify_record
 d_classify_record (tree type)
 {
   Type *t = TYPE_LANG_FRONTEND (type);
+  TypeClass *tc = t ? t->isTypeClass () : NULL;
 
-  if (t && t->ty == Tclass)
+  if (tc != NULL)
     {
-      TypeClass *tc = (TypeClass *) t;
-
       /* extern(C++) interfaces get emitted as classes.  */
       if (tc->sym->isInterfaceDeclaration ()
 	  && !tc->sym->isCPPinterface ())
@@ -1814,12 +1813,10 @@ static tree
 d_build_eh_runtime_type (tree type)
 {
   Type *t = TYPE_LANG_FRONTEND (type);
+  gcc_assert (t != NULL);
+  t = t->toBasetype ();
 
-  if (t != NULL)
-    t = t->toBasetype ();
-
-  gcc_assert (t != NULL && t->ty == Tclass);
-  ClassDeclaration *cd = ((TypeClass *) t)->sym;
+  ClassDeclaration *cd = t->isTypeClass ()->sym;
   tree decl;
 
   if (cd->isCPPclass ())
diff --git a/gcc/d/decl.cc b/gcc/d/decl.cc
index 84aa42c..0586863 100644
--- a/gcc/d/decl.cc
+++ b/gcc/d/decl.cc
@@ -313,9 +313,9 @@ public:
     TemplateInstance *ti = NULL;
 
     if (tb->ty == Tstruct)
-      ti = ((TypeStruct *) tb)->sym->isInstantiated ();
+      ti = tb->isTypeStruct ()->sym->isInstantiated ();
     else if (tb->ty == Tclass)
-      ti = ((TypeClass *) tb)->sym->isInstantiated ();
+      ti = tb->isTypeClass ()->sym->isInstantiated ();
 
     /* Return type is instantiated from this template declaration, walk over
        all members of the instance.  */
@@ -620,7 +620,7 @@ public:
     if (have_typeinfo_p (Type::dtypeinfo))
       create_typeinfo (d->type, NULL);
 
-    TypeEnum *tc = (TypeEnum *) d->type;
+    TypeEnum *tc = d->type->isTypeEnum ();
     if (tc->sym->members && !d->type->isZeroInit ())
       {
 	/* Generate static initializer.  */
@@ -717,11 +717,8 @@ public:
 	  }
 	else
 	  {
-	    if (d->type->ty == Tstruct)
-	      {
-		StructDeclaration *sd = ((TypeStruct *) d->type)->sym;
-		DECL_INITIAL (decl) = layout_struct_initializer (sd);
-	      }
+	    if (TypeStruct *ts = d->type->isTypeStruct ())
+	      DECL_INITIAL (decl) = layout_struct_initializer (ts->sym);
 	    else
 	      {
 		Expression *e = d->type->defaultInitLiteral (d->loc);
@@ -813,9 +810,8 @@ public:
       return;
 
     /* Check if any errors occurred when running semantic.  */
-    if (d->type->ty == Tfunction)
+    if (TypeFunction *tf = d->type->isTypeFunction ())
       {
-	TypeFunction *tf = (TypeFunction *) d->type;
 	if (tf->next == NULL || tf->next->ty == Terror)
 	  return;
       }
diff --git a/gcc/d/expr.cc b/gcc/d/expr.cc
index 1940480..9c80db1 100644
--- a/gcc/d/expr.cc
+++ b/gcc/d/expr.cc
@@ -62,10 +62,9 @@ class ExprVisitor : public Visitor
   {
     t = t->baseElemOf ();
 
-    if (t->ty == Tstruct)
+    if (TypeStruct *ts = t->isTypeStruct ())
       {
-	StructDeclaration *sd = ((TypeStruct *) t)->sym;
-	if (sd->postblit)
+	if (ts->sym->postblit)
 	  return true;
       }
 
@@ -78,10 +77,9 @@ class ExprVisitor : public Visitor
   {
     t = t->baseElemOf ();
 
-    if (t->ty == Tstruct)
+    if (TypeStruct *ts = t->isTypeStruct ())
       {
-	StructDeclaration *sd = ((TypeStruct *) t)->sym;
-	if (sd->dtor)
+	if (ts->sym->dtor)
 	  return true;
       }
 
@@ -298,17 +296,16 @@ public:
 	      this->result_ = build_boolop (TRUTH_ORIF_EXPR, req, ieq);
 	  }
       }
-    else if (tb1->ty == Tstruct)
+    else if (TypeStruct *ts = tb1->isTypeStruct ())
       {
 	/* For struct objects, identity is defined as bits in operands being
 	   identical also.  Alignment holes in structs are ignored.  */
-	StructDeclaration *sd = ((TypeStruct *) tb1)->sym;
 	tree t1 = build_expr (e->e1);
 	tree t2 = build_expr (e->e2);
 
 	gcc_assert (same_type_p (tb1, tb2));
 
-	this->result_ = build_struct_comparison (code, sd, t1, t2);
+	this->result_ = build_struct_comparison (code, ts->sym, t1, t2);
       }
     else
       {
@@ -345,7 +342,7 @@ public:
 	    Or when generating a NE expression:
 		e1.length != e2.length || memcmp(e1.ptr, e2.ptr, size) != 0;  */
 	if ((t1elem->isintegral () || t1elem->ty == Tvoid
-	     || (t1elem->ty == Tstruct && !((TypeStruct *)t1elem)->sym->xeq))
+	     || (t1elem->ty == Tstruct && !t1elem->isTypeStruct ()->sym->xeq))
 	    && t1elem->ty == t2elem->ty)
 	  {
 	    tree t1 = d_array_convert (e->e1);
@@ -367,7 +364,7 @@ public:
 	    /* Compare arrays using memcmp if possible, otherwise for structs,
 	       each field is compared inline.  */
 	    if (t1elem->ty != Tstruct
-		|| identity_compare_p (((TypeStruct *) t1elem)->sym))
+		|| identity_compare_p (t1elem->isTypeStruct ()->sym))
 	      {
 		tree size = size_mult_expr (t1len, size_int (t1elem->size ()));
 		tree tmemcmp = builtin_decl_explicit (BUILT_IN_MEMCMP);
@@ -377,7 +374,7 @@ public:
 	      }
 	    else
 	      {
-		StructDeclaration *sd = ((TypeStruct *) t1elem)->sym;
+		StructDeclaration *sd = t1elem->isTypeStruct ()->sym;
 
 		result = build_array_struct_comparison (code, sd, t1len,
 							t1ptr, t2ptr);
@@ -432,24 +429,22 @@ public:
 	    this->result_ = result;
 	  }
       }
-    else if (tb1->ty == Tstruct)
+    else if (TypeStruct *ts = tb1->isTypeStruct ())
       {
 	/* Equality for struct objects means the logical product of all
 	   equality results of the corresponding object fields.  */
-	StructDeclaration *sd = ((TypeStruct *) tb1)->sym;
 	tree t1 = build_expr (e->e1);
 	tree t2 = build_expr (e->e2);
 
 	gcc_assert (same_type_p (tb1, tb2));
 
-	this->result_ = build_struct_comparison (code, sd, t1, t2);
+	this->result_ = build_struct_comparison (code, ts->sym, t1, t2);
       }
     else if (tb1->ty == Taarray && tb2->ty == Taarray)
       {
 	/* Use _aaEqual() for associative arrays.  */
-	TypeAArray *taa1 = (TypeAArray *) tb1;
 	tree result = build_libcall (LIBCALL_AAEQUAL, e->type, 3,
-				     build_typeinfo (e->loc, taa1),
+				     build_typeinfo (e->loc, tb1),
 				     build_expr (e->e1),
 				     build_expr (e->e2));
 
@@ -477,9 +472,7 @@ public:
   void visit (InExp *e)
   {
     Type *tb2 = e->e2->type->toBasetype ();
-    gcc_assert (tb2->ty == Taarray);
-
-    Type *tkey = ((TypeAArray *) tb2)->index->toBasetype ();
+    Type *tkey = tb2->isTypeAArray ()->index->toBasetype ();
     tree key = convert_expr (build_expr (e->e1), e->e1->type, tkey);
 
     /* Build a call to _aaInX().  */
@@ -1031,7 +1024,7 @@ public:
 	tree t1 = build_expr (e->e1);
 	tree t2 = convert_for_assignment (build_expr (e->e2),
 					  e->e2->type, e->e1->type);
-	StructDeclaration *sd = ((TypeStruct *) tb1)->sym;
+	StructDeclaration *sd = tb1->isTypeStruct ()->sym;
 
 	/* Look for struct = 0.  */
 	if (e->e2->op == TOKint64)
@@ -1193,7 +1186,7 @@ public:
     if (tb1->ty == Taarray)
       {
 	/* Get the key for the associative array.  */
-	Type *tkey = ((TypeAArray *) tb1)->index->toBasetype ();
+	Type *tkey = tb1->isTypeAArray ()->index->toBasetype ();
 	tree key = convert_expr (build_expr (e->e2), e->e2->type, tkey);
 	libcall_fn libcall;
 	tree tinfo, ptr;
@@ -1476,10 +1469,9 @@ public:
 	Type *telem = tb1->nextOf ()->baseElemOf ();
 	tree ti = null_pointer_node;
 
-	if (telem->ty == Tstruct)
+	if (TypeStruct *ts = telem->isTypeStruct ())
 	  {
 	    /* Might need to run destructor on array contents.  */
-	    TypeStruct *ts = (TypeStruct *) telem;
 	    if (ts->sym->dtor)
 	      ti = build_typeinfo (e->loc, tb1->nextOf ());
 	  }
@@ -1493,11 +1485,10 @@ public:
 	/* For pointers to a struct instance, if the struct has overloaded
 	   operator delete, then that operator is called.  */
 	t1 = build_address (t1);
-	Type *tnext = ((TypePointer *)tb1)->next->toBasetype ();
+	Type *tnext = tb1->isTypePointer ()->next->toBasetype ();
 
-	if (tnext->ty == Tstruct)
+	if (TypeStruct *ts = tnext->isTypeStruct ())
 	  {
-	    TypeStruct *ts = (TypeStruct *)tnext;
 	    if (ts->sym->dtor)
 	      {
 		tree ti = build_typeinfo (e->loc, tnext);
@@ -1527,7 +1518,7 @@ public:
     if (e->e1->type->toBasetype ()->ty == Taarray)
       {
 	Type *tb = e->e1->type->toBasetype ();
-	Type *tkey = ((TypeAArray *) tb)->index->toBasetype ();
+	Type *tkey = tb->isTypeAArray ()->index->toBasetype ();
 	tree index = convert_expr (build_expr (e->e2), e->e2->type, tkey);
 
 	this->result_ = build_libcall (LIBCALL_AADELX, Type::tbool, 3,
@@ -1623,7 +1614,7 @@ public:
        allocated in memory because its address is taken.  */
     if (tnext && tnext->ty == Tstruct)
       {
-	StructDeclaration *sd = ((TypeStruct *) tnext)->sym;
+	StructDeclaration *sd = tnext->isTypeStruct ()->sym;
 
 	for (size_t i = 0; i < sd->fields.length; i++)
 	  {
@@ -1998,7 +1989,7 @@ public:
 	      }
 	    else if (tb1->ty == Tpointer && tb1->nextOf ()->ty == Tstruct)
 	      {
-		StructDeclaration *sd = ((TypeStruct *) tb1->nextOf ())->sym;
+		StructDeclaration *sd = tb1->nextOf ()->isTypeStruct ()->sym;
 		if (sd->inv != NULL)
 		  {
 		    Expressions args;
@@ -2089,7 +2080,7 @@ public:
 	ci = indirect_ref (ptr_type_node, ci);
 
 	/* Add extra indirection for interfaces.  */
-	if (((TypeClass *) type)->sym->isInterfaceDeclaration ())
+	if (type->isTypeClass ()->sym->isInterfaceDeclaration ())
 	  ci = indirect_ref (ptr_type_node, ci);
 
 	this->result_ = build_nop (build_ctype (e->type), ci);
@@ -2288,9 +2279,8 @@ public:
       {
 	/* Allocating a new class.  */
 	tb = e->newtype->toBasetype ();
-	gcc_assert (tb->ty == Tclass);
 
-	ClassDeclaration *cd = ((TypeClass *) tb)->sym;
+	ClassDeclaration *cd = tb->isTypeClass ()->sym;
 	tree type = build_ctype (tb);
 	tree setup_exp = NULL_TREE;
 	tree new_call;
@@ -2368,10 +2358,9 @@ public:
       {
 	/* Allocating memory for a new struct.  */
 	Type *htype = e->newtype->toBasetype ();
-	gcc_assert (htype->ty == Tstruct);
 	gcc_assert (!e->onstack);
 
-	TypeStruct *stype = (TypeStruct *) htype;
+	TypeStruct *stype = htype->isTypeStruct ();
 	StructDeclaration *sd = stype->sym;
 	tree new_call;
 
@@ -2443,8 +2432,7 @@ public:
       {
 	/* Allocating memory for a new D array.  */
 	tb = e->newtype->toBasetype ();
-	gcc_assert (tb->ty == Tarray);
-	TypeDArray *tarray = (TypeDArray *) tb;
+	TypeDArray *tarray = tb->isTypeDArray ();
 
 	gcc_assert (!e->allocator);
 	gcc_assert (e->arguments && e->arguments->length >= 1);
@@ -2511,7 +2499,7 @@ public:
     else if (tb->ty == Tpointer)
       {
 	/* Allocating memory for a new pointer.  */
-	TypePointer *tpointer = (TypePointer *) tb;
+	TypePointer *tpointer = tb->isTypePointer ();
 
 	if (tpointer->next->size () == 0)
 	  {
@@ -2666,7 +2654,7 @@ public:
 
     /* Implicitly convert void[n] to ubyte[n].  */
     if (tb->ty == Tsarray && tb->nextOf ()->toBasetype ()->ty == Tvoid)
-      tb = Type::tuns8->sarrayOf (((TypeSArray *) tb)->dim->toUInteger ());
+      tb = Type::tuns8->sarrayOf (tb->isTypeSArray ()->dim->toUInteger ());
 
     gcc_assert (tb->ty == Tarray || tb->ty == Tsarray || tb->ty == Tpointer);
 
@@ -2781,10 +2769,9 @@ public:
   {
     /* Want the mutable type for typeinfo reference.  */
     Type *tb = e->type->toBasetype ()->mutableOf ();
-    gcc_assert (tb->ty == Taarray);
 
     /* Handle empty assoc array literals.  */
-    TypeAArray *ta = (TypeAArray *) tb;
+    TypeAArray *ta = tb->isTypeAArray ();
     if (e->keys->length == 0)
       {
 	this->result_ = build_constructor (build_ctype (ta), NULL);
@@ -3018,7 +3005,7 @@ public:
        interface offset to symbol.  */
     if (this->constp_)
       {
-	TypeClass *tc = (TypeClass *) e->type;
+	TypeClass *tc = e->type->toBasetype ()->isTypeClass ();
 	InterfaceDeclaration *to = tc->sym->isInterfaceDeclaration ();
 
 	if (to != NULL)
diff --git a/gcc/d/imports.cc b/gcc/d/imports.cc
index 2e3eb74..e6e696a 100644
--- a/gcc/d/imports.cc
+++ b/gcc/d/imports.cc
@@ -131,11 +131,11 @@ public:
 	if (type != NULL)
 	  {
 	    if (type->ty == Tenum)
-	      dsym = ((TypeEnum *) type)->sym;
+	      dsym = type->isTypeEnum ()->sym;
 	    else if (type->ty == Tstruct)
-	      dsym = ((TypeStruct *) type)->sym;
+	      dsym = type->isTypeStruct ()->sym;
 	    else if (type->ty == Tclass)
-	      dsym = ((TypeClass *) type)->sym;
+	      dsym = type->isTypeClass ()->sym;
 	  }
       }
 
diff --git a/gcc/d/typeinfo.cc b/gcc/d/typeinfo.cc
index 8249fa7..73443ea 100644
--- a/gcc/d/typeinfo.cc
+++ b/gcc/d/typeinfo.cc
@@ -140,7 +140,7 @@ get_typeinfo_kind (Type *type)
       return TK_TYPELIST_TYPE;
 
     case Tclass:
-      if (((TypeClass *) type)->sym->isInterfaceDeclaration ())
+      if (type->isTypeClass ()->sym->isInterfaceDeclaration ())
 	return TK_INTERFACE_TYPE;
       else
 	return TK_CLASSINFO_TYPE;
@@ -619,8 +619,7 @@ public:
 
   void visit (TypeInfoEnumDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tenum);
-    TypeEnum *ti = (TypeEnum *) d->tinfo;
+    TypeEnum *ti = d->tinfo->isTypeEnum ();
     EnumDeclaration *ed = ti->sym;
 
     /* The vtable for TypeInfo_Enum.  */
@@ -652,8 +651,7 @@ public:
 
   void visit (TypeInfoPointerDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tpointer);
-    TypePointer *ti = (TypePointer *) d->tinfo;
+    TypePointer *ti = d->tinfo->isTypePointer ();
 
     /* The vtable for TypeInfo_Pointer.  */
     this->layout_base (Type::typeinfopointer);
@@ -669,8 +667,7 @@ public:
 
   void visit (TypeInfoArrayDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tarray);
-    TypeDArray *ti = (TypeDArray *) d->tinfo;
+    TypeDArray *ti = d->tinfo->isTypeDArray ();
 
     /* The vtable for TypeInfo_Array.  */
     this->layout_base (Type::typeinfoarray);
@@ -687,8 +684,7 @@ public:
 
   void visit (TypeInfoStaticArrayDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tsarray);
-    TypeSArray *ti = (TypeSArray *) d->tinfo;
+    TypeSArray *ti = d->tinfo->isTypeSArray ();
 
     /* The vtable for TypeInfo_StaticArray.  */
     this->layout_base (Type::typeinfostaticarray);
@@ -708,8 +704,7 @@ public:
 
   void visit (TypeInfoAssociativeArrayDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Taarray);
-    TypeAArray *ti = (TypeAArray *) d->tinfo;
+    TypeAArray *ti = d->tinfo->isTypeAArray ();
 
     /* The vtable for TypeInfo_AssociativeArray.  */
     this->layout_base (Type::typeinfoassociativearray);
@@ -728,8 +723,7 @@ public:
 
   void visit (TypeInfoVectorDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tvector);
-    TypeVector *ti = (TypeVector *) d->tinfo;
+    TypeVector *ti = d->tinfo->isTypeVector ();
 
     /* The vtable for TypeInfo_Vector.  */
     this->layout_base (Type::typeinfovector);
@@ -746,8 +740,8 @@ public:
 
   void visit (TypeInfoFunctionDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tfunction && d->tinfo->deco != NULL);
-    TypeFunction *ti = (TypeFunction *) d->tinfo;
+    TypeFunction *ti = d->tinfo->isTypeFunction ();
+    gcc_assert (ti->deco != NULL);
 
     /* The vtable for TypeInfo_Function.  */
     this->layout_base (Type::typeinfofunction);
@@ -767,8 +761,8 @@ public:
 
   void visit (TypeInfoDelegateDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tdelegate && d->tinfo->deco != NULL);
-    TypeDelegate *ti = (TypeDelegate *) d->tinfo;
+    TypeDelegate *ti = d->tinfo->isTypeDelegate ();
+    gcc_assert (ti->deco != NULL);
 
     /* The vtable for TypeInfo_Delegate.  */
     this->layout_base (Type::typeinfodelegate);
@@ -801,8 +795,7 @@ public:
 
   void visit (TypeInfoClassDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tclass);
-    TypeClass *ti = (TypeClass *) d->tinfo;
+    TypeClass *ti = d->tinfo->isTypeClass ();
     ClassDeclaration *cd = ti->sym;
 
     /* The vtable for ClassInfo.  */
@@ -994,8 +987,7 @@ public:
 
   void visit (TypeInfoInterfaceDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tclass);
-    TypeClass *ti = (TypeClass *) d->tinfo;
+    TypeClass *ti = d->tinfo->isTypeClass ();
 
     if (!ti->sym->vclassinfo)
       ti->sym->vclassinfo = TypeInfoClassDeclaration::create (ti);
@@ -1028,8 +1020,7 @@ public:
 
   void visit (TypeInfoStructDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Tstruct);
-    TypeStruct *ti = (TypeStruct *) d->tinfo;
+    TypeStruct *ti = d->tinfo->isTypeStruct ();
     StructDeclaration *sd = ti->sym;
 
     /* The vtable for TypeInfo_Struct.  */
@@ -1128,8 +1119,7 @@ public:
 
   void visit (TypeInfoTupleDeclaration *d)
   {
-    gcc_assert (d->tinfo->ty == Ttuple);
-    TypeTuple *ti = (TypeTuple *) d->tinfo;
+    TypeTuple *ti = d->tinfo->isTypeTuple ();
 
     /* The vtable for TypeInfo_Tuple.  */
     this->layout_base (Type::typeinfotypelist);
@@ -1323,8 +1313,7 @@ public:
 
   void visit (TypeInfoClassDeclaration *tid)
   {
-    gcc_assert (tid->tinfo->ty == Tclass);
-    TypeClass *tc = (TypeClass *) tid->tinfo;
+    TypeClass *tc = tid->tinfo->isTypeClass ();
     tid->csym = get_classinfo_decl (tc->sym);
   }
 };
diff --git a/gcc/d/types.cc b/gcc/d/types.cc
index f3a1c47..cb9a6de 100644
--- a/gcc/d/types.cc
+++ b/gcc/d/types.cc
@@ -498,9 +498,9 @@ merge_aggregate_types (Type *type, tree deco)
   AggregateDeclaration *sym;
 
   if (type->ty == Tstruct)
-    sym = ((TypeStruct *) type)->sym;
+    sym = type->isTypeStruct ()->sym;
   else if (type->ty == Tclass)
-    sym = ((TypeClass *) type)->sym;
+    sym = type->isTypeClass ()->sym;
   else
     gcc_unreachable ();
 
@@ -671,7 +671,7 @@ public:
 
   void visit (TypeVector *t)
   {
-    int nunits = ((TypeSArray *) t->basetype)->dim->toUInteger ();
+    int nunits = t->basetype->isTypeSArray ()->dim->toUInteger ();
     tree inner = build_ctype (t->elementType ());
 
     /* Same rationale as void static arrays.  */