rust: proc() syntax obsolete, thread not in prelude

snippets/rust.snippets

@@ -161,8 +161,12 @@ snippet ss "static string declaration"
 snippet stat "static item declaration"
 	static ${1}: ${2:usize} = ${0};
 # Concurrency
-snippet spawn "spawn a task or thread"
-	spawn(proc() {
+snippet scoped "spawn a scoped thread"
+	thread::scoped(${1:move }|| {
+		${0}
+	});
+snippet spawn "spawn a thread"
+	thread::spawn(${1:move }|| {
 		${0}
 	});
 snippet chan "Declare (Sender, Receiver) pair of asynchronous channel()"