That's not really what I mean (I meant that it's not going to result in any difference in which system calls are made etc). If you flush manually, the runtime-p

That's not really what I mean (I meant that it's not going to result in any difference in which system calls are made etc). If you flush manually, the runtime-provided routine that closes all streams (see e.g. https://www.gnu.org/software/libc/manual/html_node/Normal-Termination.html https://www.gnu.org/software/libc/manual/html_node/Normal-Te...) will just do nothing, so you get a little bit of overhead from that