Platform endianness check

How do I check the endianness of the platform in rust?

Thanks in advance.

TLDR is cfg(target_endian), but so far as I know all supported platforms are little-endian anyway.

FWIW, you should in general just be able to use the various integer methods like {from,to}_{be,le,ne}{,_bytes}


Sigh. No. If you look on list of supported platforms then you'll find both mips-unknown-linux-gnu and powerpc-unknown-linux-gnu in there.

And these are not exactly rare or exotic: many cheap routers use MIPS precisely because these are big endian and thus more efficient if the only thing you need to do it to process TCP/IP packets.

And you can test that code with miri's --target option without purchasing such router, too.


IBM mainframe s390x-unknown-linux-gnu is big endian too, and supported at tier 2 in Rust.

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I stand corrected! I checked what endianness was actually available out there a while ago and got a lot of "some obscure and no longer in production super-computers, and since weird Chinese panels that used the big endian mode of ARM for some reason". Don't know how I missed MIPS being in use still.