fricgan is an input/output library for byte based manipulations, without
requiring std. It has additional features (where std is enabled), but
the core feature set is designed to provide the minimal types and support
for cross-language IO work.
At this time it does not implement byte order manipulation, as the std
primitives for the integral types support swap_bytes, {to,from}_be,
and {to,from}_le. (If you are implementing without std then presumably
you already know how to do this, and understand why it would just clutter
this library up).