   // Generate a seed value from the current state of this hasher.
   // FIXME(hasher): Remove
   @inline(__always)
-  internal func _generateSeed() -> (UInt64, UInt64) {
+  internal func _generateSeed() -> Hasher._Seed {
     return _core._generateSeed()
   }
 

  @usableFromInline
  internal typealias Core = _BufferingHasher<RawCore>

  internal var _core: Core

  /// Creates a new hasher.

  /// Initialize a new hasher using the specified seed value.
  @usableFromInline
  @_effects(releasenone)
  internal init(_seed seed: _Seed) {
    self._core = Core(seed: seed)
  }

