This is a great, favorite trick of mine. It has some surprising edge cases, however! For example:
[grahamc@Petunia:~]$ cat <(date)
Sat Dec 14 21:08:17 EST 2019
[grahamc@Petunia:~]$ sudo cat <(date)
cat: /proc/self/fd/13: No such file or directory
Cool! You can use a similar trick to give another program access to some of your process’s memory, using memfd_create.