Hi all, I have streamlined my c-based superfast vector copy lib in stis-supervectors to get a self contained c-file that generates *vector-copy! that handles all types of bytevectors and SCM vectors, can have different directions can have different endianes and can have arbitrary intervals like pythons [1:2:3]. Only the reasonable safe variants are possible e.g. not signed to unsigned and not u64 to u32. But we do doubles -> float (although it can be dangerous). Takes about 10s with O2 to compile. We may wonder why we need a C based version of this. Well for one thing it can benchmark guiles' own routines. And all these copy routines can be made quite fast on contemporary computers (memcpy speed). If people are interested in including it in guile, I'll be happy to sign over the copyright to FSF, else it is a nice lib to play with. If there is interest I can make a small project to host it outside the stis-supervector lib where a scm interface at a higher level can be made. Link: https://gitlab.com/tampe/stis-supervectors/-/blob/main/src/vector-copy.c Regards Stefan