Macro dbg

macro_rules! dbg {
    ($val:expr $(,)?) => { ... };
    ($($val:expr),+ $(,)?) => { ... };
}

Available on crate feature std only.

Outputs the information of the expression(s) to stderr.

use testutils::dbg;
let width = 30;
let label = "size";

dbg!(width, label);
// Outputs:
//  width: i32 = 30
//  label: &str = "size"