Macro erg_common::fmt_option

source ·

macro_rules! fmt_option {
    ($ex: expr $(,)*) => { ... };
    ($ex: expr $(,)*, else $els: expr $(,)*) => { ... };
    (pre $prefix: expr, $ex: expr $(,)*) => { ... };
    ($ex: expr, post $postfix: expr $(,)*) => { ... };
    ($prefix: expr, $ex: expr, $postfix: expr $(,)*) => { ... };
}

Expand description

assert_eq!(fmt_option!(Some(1)), "1");
assert_eq!(fmt_option!(None::<i32>), "");
assert_eq!(fmt_option!(None::<i32>, else 1), "1");
assert_eq!(fmt_option!(Some(1), post ","), "1,");
assert_eq!(fmt_option!("[", Some(1), "]"), "[1]");