CountCharacters can be const so it is now.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/Document.h b/src/Document.h
index 477b4dc60..e808bb37f 100644
--- a/src/Document.h
+++ b/src/Document.h
@@ -321,7 +321,7 @@ public:
 	int SetLineIndentation(int line, int indent);
 	int GetLineIndentPosition(int line) const;
 	int GetColumn(int position);
-	int CountCharacters(int startPos, int endPos);
+	int CountCharacters(int startPos, int endPos) const;
 	int FindColumn(int line, int column);
 	void Indent(bool forwards, int lineBottom, int lineTop);
 	static std::string TransformLineEnds(const char *s, size_t len, int eolModeWanted);