Nicer flyweight API

aeron-rs/src/command/flyweight.rs

@@ -11,20 +11,30 @@ where
     _phantom: PhantomData<S>,
 }
 
+pub struct Unchecked;
+
+impl<A> Flyweight<A, Unchecked>
+where
+    A: AtomicBuffer,
+{
+    pub fn new<S>(buffer: A, offset: IndexT) -> Result<Flyweight<A, S>>
+    where
+        S: Sized
+    {
+        buffer.overlay::<S>(offset)?;
+        Ok(Flyweight {
+            buffer,
+            base_offset: offset,
+            _phantom: PhantomData
+        })
+    }
+}
+
 impl<A, S> Flyweight<A, S>
 where
     A: AtomicBuffer,
     S: Sized,
 {
-    pub fn new(buffer: A, offset: IndexT) -> Result<Flyweight<A, S>> {
-        buffer.overlay::<S>(offset)?;
-        Ok(Flyweight {
-            buffer,
-            base_offset: offset,
-            _phantom: PhantomData,
-        })
-    }
-
     pub(crate) fn get_struct(&self) -> &S {
         // UNWRAP: Bounds check performed during initialization
         self.buffer.overlay::<S>(self.base_offset).unwrap()

aeron-rs/src/driver_proxy.rs

@@ -36,9 +36,8 @@ where
     pub fn terminate_driver(&mut self, _token_buffer: Option<&[u8]>) -> Result<()> {
         let _client_id = self.client_id;
         self.write_command_to_driver(|buffer: &mut [u8], _length: &mut IndexT| {
-            // FIXME: This method signature is ugly.
             // UNWRAP: Buffer from `write_command` guaranteed to be long enough for `TerminateDriverDefn`
-            let _request: Flyweight<_, TerminateDriverDefn> = Flyweight::new(buffer, 0).unwrap();
+            let _request = Flyweight::new::<TerminateDriverDefn>(buffer, 0).unwrap();
 
             // FIXME: Uncommenting this causes termination to not succeed
             /*