1 files changed, 3 insertions, 1 deletions
diff --git a/rst_parser/arc_factored.h b/rst_parser/arc_factored.h
index a95f8230..d9a0bb24 100644
--- a/rst_parser/arc_factored.h
+++ b/rst_parser/arc_factored.h
@@ -28,10 +28,12 @@ struct ArcFeatureFunction;
 class ArcFactoredForest {
  public:
   ArcFactoredForest() : num_words_() {}
-  explicit ArcFactoredForest(short num_words) {
+  explicit ArcFactoredForest(short num_words) : num_words_(num_words) {
     resize(num_words);
   }
 
+  unsigned size() const { return num_words_; }
+
   void resize(unsigned num_words) {
     num_words_ = num_words;
     root_edges_.clear();