Re: Compatibility types, type aliases, and distinct types - Mailing list pgsql-hackers

Peter Eisentraut <peter_e@gmx.net> writes:
> On Monday 18 August 2008 17:26:16 Tom Lane wrote:
> This feature by itself could be quite useful, and then we could simply
> add something like
> CREATE TYPE newtype AS oldtype WITH CASTS;
>> 
>> This seems like a great way to get lost in "ambiguous function" hell ...

> I don't understand this point.  No new overloaded functions are being defined.

If the type has no functions of its own, then the only way to make it
easily usable is to throw in implicit conversions *in both directions*
between it and the type it's an alias for.  You're going to find that
that's a problem.
        regards, tom lane