Macro text 

macro_rules! text {
    ($fmt:literal $(, $arg:expr)* $(,)?) => { ... };
}

Text("…") with interpolation, the way Swift writes Text("\(name)!").

The function form takes a &str, so an interpolated label reads text(&format!("{}!", name)). This says the same thing in the order Swift says it:

text!("{}!", selected)