add_double_to_active_record.rb

module CustomColumnTypes
    def double(*args)
        args.last[:limit] = 53 if args.last.is_a? Hash
        float *args
    end 
end 

module ActiveRecord
    module ConnectionAdapters
        class Table
            include CustomColumnTypes
        end 
        class TableDefinition
            include CustomColumnTypes
        end 
    end 
end