Macro si_trace_print::defn

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

debug eprintln! in a function when entering.

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

use si_trace_print::{defn, defx};
fn func1() {
    defn!("hello");
}
fn main() {
    defn!();
    func1();
    defx!();
}

prints

→main:
    →func1: hello
←main:

Uses sn().

For debug builds.