> What about casting the decode result? Like:
>
> cast(decode(1 = 1, 'a', 'ab') as varchar(2)) || 'c'
>

varchar('a ') is still 'a '

trim(decode)||'c' works, but nested decodes get so cluttered... and
it's still painfully not-like-any-other-language, a source of bugs for
me.