Container Type Cleared

I am trying to use TSets and TMaps with structures, but it will not allow me.

If I create a TSet or TMap from an int, then change the variable to my structure, I get the following message:

“Container type cleared because “integer” does not have a GetHashType function. Maps and sets require a hash function to insert and find elements.”

It is saying it was cleared because something integer lacks, yet it only says that when changing the variable type away from int.

Is there anyway to create a TSet or TMap using structures?