1 files changed, 8 insertions, 0 deletions
diff --git a/src/main/java/org/anarres/cpp/LexerSource.java b/src/main/java/org/anarres/cpp/LexerSource.java
index 7e39a21..cf4296f 100644
--- a/src/main/java/org/anarres/cpp/LexerSource.java
+++ b/src/main/java/org/anarres/cpp/LexerSource.java
@@ -16,6 +16,7 @@
  */
 package org.anarres.cpp;
 
+import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.Reader;
 import javax.annotation.Nonnull;
@@ -24,6 +25,13 @@ import static org.anarres.cpp.Token.*;
 /** Does not handle digraphs. */
 public class LexerSource extends Source {
 
+    @Nonnull
+    protected static BufferedReader toBufferedReader(@Nonnull Reader r) {
+        if (r instanceof BufferedReader)
+            return (BufferedReader) r;
+        return new BufferedReader(r);
+    }
+
     private static final boolean DEBUG = false;
 
     private JoinReader reader;