introduce trackers

Trackers help us to keep the code somewhat cleaner, especially in the
statistics::calculate function.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 9d3c150..c4c70a1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,7 +16,7 @@
 //!
 //! (Look at the note on "Buffering" in the [parser
 //! module](raw/parser/index.html#buffering))
-#![feature(try_trait)]
+#![feature(try_trait, stmt_expr_attributes)]
 #[macro_use]
 extern crate quick_error;
 #[macro_use]