On Wed, 16 Jan 2019 at 14:29, James Coleman <jtc...@gmail.com> wrote: > > On Tue, Jan 15, 2019 at 8:14 PM David Rowley > > While int4pl might do what you want, some other strict function might > > not. A simple example would be a strict function that decided to > > return NULL when the two ints combined overflowed int. > > Yes, the claim about not all strict functions guarantee this (like > int4pl) made sense. > > Is your preference in this kind of case to comment the code and/or > tests but stick with int4pl even though it doesn't demonstrate the > "problem", or try to engineer a different test case such that the > *_holds results in the tests don't seem to imply we could prove more > things than we do?
I think using x+x or whatever is fine. I doubt there's a need to invent some new function that returns NULL on non-NULL input. The code you're adding has no idea about the difference between the two. It has no way to know that anyway. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
