use std::time::Instant;
pub fn exec_mes(name: &str, f: fn() -> String) {
let now = Instant::now();
let res = f();
println!("[{}] elapsed time: {:.2?}", name, now.elapsed());
assert_ne!(res, "");
if print() {
println!("\t -> value of fn: {}", res);
}
}
fn print() -> bool {
true
}