Functions: support hashing MFDataType and CPPType

source/blender/functions/FN_cpp_type.hh

@@ -66,6 +66,7 @@
  *    pointers to virtual member functions.
  */
 
+#include "BLI_hash.hh"
 #include "BLI_index_mask.hh"
 #include "BLI_math_base.h"
 #include "BLI_string_ref.hh"
@@ -481,6 +482,11 @@ class CPPType {
     return default_value_;
   }
 
+  uint32_t hash() const
+  {
+    return DefaultHash<const CPPType *>{}(this);
+  }
+
   /**
    * Two types only compare equal when their pointer is equal. No two instances of CPPType for the
    * same C++ type should be created.

source/blender/functions/FN_multi_function_data_type.hh

@@ -108,6 +108,11 @@ class MFDataType {
     BLI_assert(false);
     return "";
   }
+
+  uint hash() const
+  {
+    return DefaultHash<CPPType>{}(*type_) + (uint32_t)category_;
+  }
 };
 
 inline bool operator==(const MFDataType &a, const MFDataType &b)