Make PolicyTraits::transfer_uses_memcpy() true for node_hash_* tables.

This should enable binary size savings for now and more efficiency improvements with small buffer optimization.

PiperOrigin-RevId: 564741270
Change-Id: Icf204d88256243eb60464439a52dd589d7a559cb

1 files changed, 4 insertions, 2 deletions

diff --git a/absl/container/internal/common_policy_traits.h b/absl/container/internal/common_policy_traits.h
index 3558a543..57eac678 100644
--- a/absl/container/internal/common_policy_traits.h
+++ b/absl/container/internal/common_policy_traits.h
@@ -93,11 +93,13 @@ struct common_policy_traits {
   struct Rank0 : Rank1 {};
 
   // Use auto -> decltype as an enabler.
+  // P::transfer returns std::true_type if transfer uses memcpy (e.g. in
+  // node_slot_policy).
   template <class Alloc, class P = Policy>
   static auto transfer_impl(Alloc* alloc, slot_type* new_slot,
                             slot_type* old_slot, Rank0)
-      -> decltype((void)P::transfer(alloc, new_slot, old_slot)) {
-    P::transfer(alloc, new_slot, old_slot);
+      -> decltype(P::transfer(alloc, new_slot, old_slot)) {
+    return P::transfer(alloc, new_slot, old_slot);
   }
 #if defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606
   // This overload returns true_type for the trait below.