Similar to the automatic implicit conversion to boolean values in weakly typed languages

Examples

use weak_true::weak_true;

#[weak_true]
fn main() {
    let mut a = vec![-1, 0, 1, 2];
    let mut b = vec![4, 3];

    while a && a[a.len()-1] {
        b.push(a.pop().unwrap());
    }

    assert_eq!(a, vec![-1, 0]);
    assert_eq!(b, vec![4, 3, 2, 1]);
}

use weak_true::WeakTrue;

assert!("c".weak_true());
assert!('c'.weak_true());
assert!('\0'.weak_true());
assert!([0].weak_true());
assert!((&0 as *const i32).weak_true());
assert!(Some(0).weak_true());

assert!(f64::NAN.weak_false());
assert!(0.0.weak_false());
assert!(0.weak_false());
assert!("".weak_false());
assert!([0; 0].weak_false());

assert_eq!(1.weak_then(|| "ok"), Some("ok"));
assert_eq!(0.weak_then(|| "ok"), None);