Tools for providing a RIOT main function
The main contribution of this module is the riot_main macro.
The alternative to using that (other than doing it manually) is to have C code along with the Rust application that occupies the main function.
In these cases, Rust code can be called into from the main C code by declaring the entry
#[no_mangle] pub extern "C", and having analogous
extern functions in the calling
A result trait for main methods, analogous to std::process::Termination