Add explanatory comment

apache · Feb 12, 2025 · b4eb09f · b4eb09f
1 parent 2d1965f
commit b4eb09f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/cpp/src/arrow/csv/parser.cc b/cpp/src/arrow/csv/parser.cc
@@ -180,6 +180,10 @@ class ResizableValueDescWriter : public ValueDescWriter<ResizableValueDescWriter
       }
       status_ &= std::move(resize_status);
     }
+    // The `values_` pointer may have become invalid if the `Resize` call above failed.
+    // Note that ResizableValueDescWriter is less performance-critical than
+    // PresizedValueDescWriter, as it should only be called on the first line(s)
+    // of CSV data.
     if (ARROW_PREDICT_TRUE(status_.ok())) {
       values_[values_size_++] = v;
     }