Inline the run_gc method.

src/iface/neighbor.rs

@@ -7,9 +7,7 @@ use wire::{EthernetAddress, IpAddress};
 use time::{Duration, Instant};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use std::mem::replace;
-#[cfg(any(feature = "std", feature = "alloc"))]
-use std::collections::BTreeMap;
+use core::mem::replace;
 
 /// A cached neighbor.
 ///
@@ -88,26 +86,24 @@ impl<'a> Cache<'a> {
         Cache { storage, gc_threshold, silent_until: Instant::from_millis(0) }
     }
 
-    #[cfg(any(feature = "std", feature = "alloc"))]
-    fn run_gc(original_btree_map: &BTreeMap<IpAddress, Neighbor>, timestamp: Instant) -> BTreeMap<IpAddress, Neighbor> {
-        original_btree_map.into_iter()
-        .map(|(key, value)| (*key, *value))
-        .filter(|(_, v)| timestamp < v.expires_at)
-        .collect()
-    }
-
     pub(crate) fn fill(&mut self, protocol_addr: IpAddress, hardware_addr: EthernetAddress,
                        timestamp: Instant) {
         debug_assert!(protocol_addr.is_unicast());
         debug_assert!(hardware_addr.is_unicast());
 
-        let _current_storage_size = self.storage.len();
+        #[cfg(any(feature = "std", feature = "alloc"))]
+        let current_storage_size = self.storage.len();
+
         match self.storage {
             ManagedMap::Borrowed(_) =>  (),
             #[cfg(any(feature = "std", feature = "alloc"))]
             ManagedMap::Owned(ref mut map) => {
-                if _current_storage_size >= self.gc_threshold {
-                    let new_btree_map = Cache::run_gc(map, timestamp);
+                if current_storage_size >= self.gc_threshold {
+                    let new_btree_map = map.into_iter()
+                        .map(|(key, value)| (*key, *value))
+                        .filter(|(_, v)| timestamp < v.expires_at)
+                        .collect();
+
                     replace(map, new_btree_map);
                 }
             }