join vs instances

[Brad Bollenbach]

In article <MfwSQIAle7E8EwZn at jessikat.fsnet.co.uk>, Robin Becker wrote:
> In article <P2MQ7.44119$pP5.5552107 at news1.rdc1.mb.home.com>, Brad
> Bollenbach <bbollenbach at home.com> writes
> ....
>>Hope that helps,
>>
>>Brad
> it doesn't. When I have to use 'b'.data instead of 'b' it might.

I'd be curious to know when this (.data vs. builtin) matters. You'll 
either be writing code in the scope in which the UserString was 
instianted (which means, you'll know when to use .data and when not 
to), or perhaps, writing a function which requires a string arg, in 
which case you still don't have to care. You just call that func with 
foo.data if the string arg is a UserString.

I might be missing something, but I can't see a situation where you'll
find a problem.

Of course it's expected that you can't get away with simply referring to
the instance directly and expecting a string to pop out, but can you 
give an example of a gotcha with a UserString vs. builtin (that is to say, 
a scenario where you the difference between the two will make it 
impossible for you to write code that won't break)?


Brad