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 fmt_option!(Some(1)) == "1"
assert fmt_option!(None) == ""
assert fmt_option!(None, else 1) == "1"
assert fmt_option!(Some(1), post ",") == "1,"
assert fmt_option!("[", Some(1), "]") == "[1]"