can_be_bound?

# File activerecord/lib/active_record/relation/predicate_builder.rb, line 157
      def can_be_bound?(column_name, value)
        return if table.associated_with?(column_name)
        case value
        when Array, Range
          table.type(column_name).force_equality?(value)
        else
          !value.nil? && handler_for(value).is_a?(BasicObjectHandler)
        end
      end