Why not support long type hashable?

I got error below when linux build.

error : static_assert failed due to requirement ‘TModels::Value’ "TMap must have a hashable KeyType unless a custom key func is provided.

note: in instantiation of template class ‘TMap<long, long long, FDefaultSetAllocator, TDefaultMapHashableKeyFuncs<long, long long, false>>’ requested here

why not support long type?

That probably because you using native C++ integer type name while UE4 expect you to use UE4 typedefs, so try int32 for long and int64 for long long

thank you for your comment
but int and __int64 can be build
I just wondering why long type only blocked

Again, that because UE4 code expect you to use UE4 typedefs which in general you should use in UE4, did you try int32?

yeah, that worked.