Re: How to return argument data type from sql function

https://stackoverflow.com/questions/74061290/how-to-return-argument-datatype-from-sql-function#comment130780708_74061290

at this worked. In this best solution?

Padding a text typed output with actual significant spaces "works"?  It is not equivalent to a bpchar with insignificant padding spaces...

You are right. I need char(n) type and this is not working.  How to use expression in cast, like

select torus(charcol) :: CHAR( ColWidth('public', 'test',  'charcol')  ) from test

This throws error in Postgres. ColWidth is immutable and called with constant arguments so it should work. How to fix postgres to allow constant ColWidth() expression in cast ?

Andrus.