On Mon, Aug 17, 2020 at 8:31 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > "David G. Johnston" <david.g.johns...@gmail.com> writes: > > More concisely: > > > Make the first input type a candidate type. Each subsequent input type > is > > compared to the current candidate, with a new candidate being chosen only > > when there exists a non-mutal implicit cast to the new type. If at any > > point a preferred type is made a candidate then it will be chosen. > > So this is just a verbatim statement of the algorithm, which is what > I was hoping to avoid :-(. But maybe there's no simpler way. > > I got nothin'. The locking onto the preferred type is conditional on one being chosen and there doesn't seem to be any greater principle that emerges from the pairwise matching algorithm - at least given that implicit casts are essentially randomly distributed and the algorithm is order-dependent.
David J.
