1 files changed, 27 insertions, 0 deletions
diff --git a/ace/Hashable.inl b/ace/Hashable.inl
new file mode 100644
index 00000000000..554c55a5d0a
--- /dev/null
+++ b/ace/Hashable.inl
@@ -0,0 +1,27 @@
+/* -*- C++ -*- */
+
+ACE_INLINE
+ACE_Hashable::ACE_Hashable (void)
+  : hash_value_ (0)
+{
+}
+
+ACE_INLINE
+ACE_Hashable::~ACE_Hashable (void)
+{
+}
+
+ACE_INLINE u_long
+ACE_Hashable::hash (void) const
+{
+  // In doing the check below, we take chance of paying a performance
+  // price when the hash value is zero.  But, that will (hopefully)
+  // happen far less often than a non-zero value, so this caching
+  // strategy should pay off, esp. if hash computation is expensive
+  // relative to the simple comparison.
+
+  if (this->hash_value_ == 0)
+    ((ACE_Hashable *) this)->hash_value_ = this->hash_i ();
+
+  return this->hash_value_;
+}