Add `ToStr` and `ToStaticStr` traits.

Allow easy mapping of borrowed C strings to borrowed strings with
appropriate lifetimes.

I have some doubts about this, as I'm not 100% on how lifetimes interact
with the notmuch-provided strings yet.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 0f88f60..f490df7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-#![feature(libc)]
+#![feature(core, libc)]
 extern crate libc;
 
 #[macro_use]