tinydb: Update doc to reflect change from `RefCell` to `Mutex` (#663)

Fixes: #658

1 files changed, 1 insertions, 1 deletions

diff --git a/examples/tinydb.rs b/examples/tinydb.rs
index 6901a120..134d01b1 100644
--- a/examples/tinydb.rs
+++ b/examples/tinydb.rs
@@ -56,7 +56,7 @@ use tokio::prelude::*;
 /// The in-memory database shared amongst all clients.
 ///
 /// This database will be shared via `Arc`, so to mutate the internal map we're
-/// also going to use a `RefCell` for interior mutability.
+/// going to use a `Mutex` for interior mutability.
 struct Database {
     map: Mutex<HashMap<String, String>>,
 }