diff --git a/clang/lib/Tooling/Syntax/BuildTree.cpp b/clang/lib/Tooling/Syntax/BuildTree.cpp
--- a/clang/lib/Tooling/Syntax/BuildTree.cpp
+++ b/clang/lib/Tooling/Syntax/BuildTree.cpp
@@ -378,11 +378,9 @@
 
   /// Returns true if \p D is the last declarator in a chain and is thus
   /// reponsible for creating SimpleDeclaration for the whole chain.
-  template <class T>
-  bool isResponsibleForCreatingDeclaration(const T *D) const {
-    static_assert((std::is_base_of<DeclaratorDecl, T>::value ||
-                   std::is_base_of<TypedefNameDecl, T>::value),
-                  "only DeclaratorDecl and TypedefNameDecl are supported.");
+  bool isResponsibleForCreatingDeclaration(const Decl *D) const {
+    assert((isa<DeclaratorDecl, TypedefNameDecl>(D)) &&
+           "only DeclaratorDecl and TypedefNameDecl are supported.");
 
     const Decl *Next = D->getNextDeclInContext();
 
@@ -390,15 +388,14 @@
     if (Next == nullptr) {
       return true;
     }
-    const auto *NextT = dyn_cast<T>(Next);
 
     // Next sibling is not the same type, this one is responsible.
-    if (NextT == nullptr) {
+    if (D->getKind() != Next->getKind()) {
       return true;
     }
     // Next sibling doesn't begin at the same loc, it must be a different
     // declaration, so this declarator is responsible.
-    if (NextT->getBeginLoc() != D->getBeginLoc()) {
+    if (Next->getBeginLoc() != D->getBeginLoc()) {
       return true;
     }
 
@@ -1405,10 +1402,9 @@
   }
 
 private:
-  template <class T> SourceLocation getQualifiedNameStart(T *D) {
-    static_assert((std::is_base_of<DeclaratorDecl, T>::value ||
-                   std::is_base_of<TypedefNameDecl, T>::value),
-                  "only DeclaratorDecl and TypedefNameDecl are supported.");
+  SourceLocation getQualifiedNameStart(NamedDecl *D) {
+    assert((isa<DeclaratorDecl, TypedefNameDecl>(D)) &&
+           "only DeclaratorDecl and TypedefNameDecl are supported.");
 
     auto DN = D->getDeclName();
     bool IsAnonymous = DN.isIdentifier() && !DN.getAsIdentifierInfo();
@@ -1438,10 +1434,9 @@
   /// Folds SimpleDeclarator node (if present) and in case this is the last
   /// declarator in the chain it also folds SimpleDeclaration node.
   template <class T> bool processDeclaratorAndDeclaration(T *D) {
-    SourceRange Initializer = getInitializerRange(D);
-    auto Range = getDeclaratorRange(Builder.sourceManager(),
-                                    D->getTypeSourceInfo()->getTypeLoc(),
-                                    getQualifiedNameStart(D), Initializer);
+    auto Range = getDeclaratorRange(
+        Builder.sourceManager(), D->getTypeSourceInfo()->getTypeLoc(),
+        getQualifiedNameStart(D), getInitializerRange(D));
 
     // There doesn't have to be a declarator (e.g. `void foo(int)` only has
     // declaration, but no declarator).