Macro si_trace_print::ef2n

macro_rules! ef2n {
    (
        $($args:tt)*
    ) => { ... };
}

eprintln! in a function plus two namespace levels when entering.

To signify entering a function. Use this as the first eprintln! in a function.

use si_trace_print::{efn, efx};
use si_trace_print::ef2n;
fn func1() {
    ef2n!("hello");
}
fn main() {
    efn!();
    func1();
    efx!();
}

prints

→main:
    →si_trace_print::main::func1: hello
←main:

Uses sn().