-* Closures: Working on iterators
* Arrays/slices
* Trait objects
-* Drop
-* ?unsafe?
-* ?interior mutability?
* Arc, concurrency, channels: Some grep-like thing, "rgrep"
* Send, Sync
* External dependencies: regexp crate, add to rgrep
-*
\ No newline at end of file
+
+* Shared-memoty concurrency, interior mutability: Concurrent counter
+* Drop, unsafe: doubly-linked list