Macro seed::IF

macro_rules! IF {
    ( $predicate:expr => $value:expr ) => { ... };
}

IF!(predicate => expression) -> Option<expression value>

• expression is evaluated only when predicate is true (lazy eval).
• Alternative to bool::then.

Example

div![
   C!["btn", IF!(active => "active")],
   "Button",
   IF!(not(disabled) => ev(Ev::Click, Msg::Clicked)),
]