gistfile1.rs

#[no_mangle]
pub fn foo(env: *mut ErlNifEnv, argc: int, argv: *ERL_NIF_TERM) -> ERL_NIF_TERM {
    print!("Hello World from Rust\n");
    unsafe {
        let a = enif_make_atom(env, ("foo".to_c_str()).unwrap());
        return a;
    }
}

gistfile2.c

#include "erl_nif.h"

extern void foo(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);

static ErlNifFunc nif_funcs[] = {
    {"foo", 0, foo}
};

ERL_NIF_INIT(erl_nif, nif_funcs, NULL, NULL, NULL, NULL)

gistfile3.txt

$ rustc --crate-type staticlib --emit obj erl_nif.rs
$ gcc  -o erl_nif.so -fpic -shared erl_nif.c erl_nif.o /usr/local/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-59beb4f7-0.11.0-pre.so -I/usr/lib/erlang/erts-6.0/include