Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Nov 27, 2012 at 2:26 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> After making the change you propose above, it would only work for types
>> for which the cast was assignment-grade or less.
> ...but that's everything, because there's a hardcoded exception in the
> code that dictates that even if there is no entry in pg_cast, an
> assignment cast to text exists for every data type.
Ugh. I had been thinking that automatic CoerceViaIO casting only
happened for explicit casts. If that can be invoked via assignment
casts, then what you're proposing really destroys the type system
entirely, at least for functions taking text: there is absolutely
no argument such a function won't accept. I cannot support this.
regards, tom lane