I have a need to convert a (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t to a (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t Is there an easy way of doing this without doing a full copy?

I don’t think so (and there are a couple of different possible semantics for such a function). You can easily write a C binding to do it, though. Cheers, Nicolas

Ok, thanks - I was hoping for a magical solution! I’ll do a C binding - thanks again.

I believe Obj.magic does this without making a copy (disclaimer: I never touch it personally, since I don’t know what I’m doing). let i = Bigarray.Array1.create Bigarray.Int8_unsigned Bigarray.C_layout 10;; val i : (int, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t = <abstr> Bi…

I was missing this feature some time ago as well. I didn’t want to write C bindings, and I looked into if using Obj.magic was possible. Looking at the bigarray code it seemed to me to be safe in the version I looked at. I ended up just copying the whole bigarray into a new one as the code wasn’t…

I did it to get a bigarray which was correctly aligned to a word but my previous me told me that it’s probably really unsafe: dinosaure/art/blob/836e36dd4cca6958ecade683f233aa6b93003e07/lib/persistent.c#L458-L473 CAMLprim value caml_to_memory(value vbigarra…

[image] dinosaure: told me that it’s probably really unsafe: I haven’t looked very closely, but mutating the bigarray value in-place may cause some issues with operations to the original bigarray value which depend on the underlying OCaml type (eg hashing, comparing, marshalling, etc). In any…

Converting a (int, Bigarray.int8_unsigned_elt,...) to a (char, Bigarray.int8_unsigned_elt,...)

Learning

thomas_ridge July 11, 2022, 2:39pm 8

Maybe this is relevant? Casting bigarray between different kinds, using ctypes, possible problems?

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Converting a (int, Bigarray.int8_unsigned_elt,...) to a (char, Bigarray.int8_unsigned_elt,...)

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