Function none 

pub fn none<T>() -> impl Matcher<Option<T>>
where
    T: Debug,

Matches None.

use test_better_core::TestResult;
use test_better_matchers::{check, none};

fn main() -> TestResult {
    check!(None::<i32>).satisfies(none())?;
    check!(Some(0)).violates(none())?;
    Ok(())
}