Merge pull request #637 from thompsonbry/scan_fixups_01

Removes an unused operator==() implementation and adds some documentation

olc_art.hpp

@@ -47,6 +47,9 @@ struct [[nodiscard]] olc_node_header {
   }
 
 #ifndef NDEBUG
+  // This is passed as a debug callback to QSBR deallocation to be
+  // checked at the physical deallocation time. This checks that the
+  // node being deallocated has no open RCS (read_critical_section).
   static void check_on_dealloc(const void* ptr) noexcept {
     static_cast<const olc_node_header*>(ptr)->m_lock.check_on_dealloc();
   }

optimistic_lock.hpp

@@ -230,12 +230,6 @@ class [[nodiscard]] optimistic_lock final {
       return *this;
     }
 
-    // Point to the same lock and have the same version for that lock.
-    [[nodiscard]] bool operator==(
-        const read_critical_section &other) const noexcept {
-      return lock == other.lock && version == other.version;
-    }
-
     // Unlock iff it is not yet unlocked.  The read_critical_section
     // is invalidated by this method and must not be used again by the
     // caller.