class UserKey
{
    var value = 0
    routine ==( other: UserKey ){
        return value == other.value;
    }   
    routine <( other: UserKey ){
        return value < other.value;
    }   
	routine (int)( hashing = false ){
		io.writeln( 'Calling UserKey::(int)(hashing=false)', value )
        return value
	}
    routine (string)(){
		io.writeln( 'Calling UserKey::(string)()', value )
        return (string)value
    }
}

var table = { UserKey.{0} -> 0 }
var dt1 = UserKey.{ 123 }
var dt2 = UserKey.{ 456 }
var dt3 = UserKey.{ 123 }

table[ dt1 ] = 1
table[ dt2 ] = 1

io.writeln( table.find( dt3 ) != none )  # true
io.writeln( dt2 in table ); # true

dt3.value += 100
io.writeln( table.find( dt3 ) != none )


dt1.value += 100
io.writeln( table.find( UserKey.{123} ) != none )