Merge pull request openvanilla#838 from ChiahongHong/ref_count

Avoid shared_ptr copies in Span::nodeOf

Author: lukhnos

Source/Engine/gramambular2/reading_grid.cpp

@@ -577,7 +577,7 @@ void ReadingGrid::Span::removeNodesOfOrLongerThan(size_t length) {
   }
 }
 
-ReadingGrid::NodePtr ReadingGrid::Span::nodeOf(size_t length) const {
+const ReadingGrid::NodePtr& ReadingGrid::Span::nodeOf(size_t length) const {
   assert(length > 0 && length <= kMaximumSpanLength);
   return nodes_[length - 1];
 }

Source/Engine/gramambular2/reading_grid.h

@@ -216,7 +216,7 @@ class ReadingGrid {
     void clear();
     void add(const NodePtr& node);
     void removeNodesOfOrLongerThan(size_t length);
-    [[nodiscard]] NodePtr nodeOf(size_t length) const;
+    [[nodiscard]] const NodePtr& nodeOf(size_t length) const;
     [[nodiscard]] size_t maxLength() const { return maxLength_; }
 
    protected: