add std::hash<DataTamer::RegistrationID>

PickNikRobotics · Feb 1, 2024 · f2cbed0 · f2cbed0
1 parent 9f0fee3
commit f2cbed0
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/data_tamer_cpp/include/data_tamer/types.hpp b/data_tamer_cpp/include/data_tamer/types.hpp
@@ -148,3 +148,18 @@ std::string ToStr(const Schema& schema);
 [[nodiscard]] uint64_t AddFieldToHash(const TypeField& field, uint64_t hash);
 
 }   // namespace DataTamer
+
+
+template <>
+struct std::hash<DataTamer::RegistrationID>
+{
+  std::size_t operator()( const DataTamer::RegistrationID& id ) const
+  {
+    // Compute individual hash values for first, second and third
+    // http://stackoverflow.com/a/1646913/126995
+    std::size_t res = 17;
+    res = res * 31 + hash<size_t>()( id.first_index );
+    res = res * 31 + hash<size_t>()( id.fields_count );
+    return res;
+  }
+};