Implement Value::demand()
diff --git a/include/json/value.h b/include/json/value.h
index 69a0ed2..277cd45 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -524,7 +524,7 @@
/// Most general and efficient version of object-mutators.
/// \note As stated elsewhere, behavior is undefined if (end-begin) >= 2^30
/// \return non-zero, but JSON_ASSERT if this is neither object nor nullValue.
- Value const* demand(char const* begin, char const* end);
+ Value* demand(char const* begin, char const* end);
/// \brief Remove and return the named member.
///
/// Do nothing if it did not exist.