non-const write
diff --git a/include/json/writer.h b/include/json/writer.h
index bef756c..e4a761c 100644
--- a/include/json/writer.h
+++ b/include/json/writer.h
@@ -55,7 +55,7 @@
/// Write Value into document as configured in sub-class.
/// \return zero on success
/// \throw std::exception possibly, depending on configuration
- virtual int write(Value const& root) const = 0;
+ virtual int write(Value const& root) = 0;
/// Because this Builder is non-virtual, we can safely add
/// methods without a major version bump.