create global selectors

examples/global.rs

@@ -5,6 +5,7 @@
 use dioxus::prelude::*;
 
 static COUNT: GlobalSignal<i32> = Signal::global(|| 0);
+static DOUBLED_COUNT: GlobalSelector<i32> = Signal::global_selector(|| COUNT() * 2);
 
 fn main() {
     launch_desktop(app);
@@ -12,7 +13,7 @@ fn main() {
 
 fn app() -> Element {
     rsx! {
-        h1 { "High-Five counter: {COUNT}" }
+        h1 { "{COUNT} x 2 = {DOUBLED_COUNT}" }
         button { onclick: move |_| *COUNT.write() += 1, "Up high!" }
         button { onclick: move |_| *COUNT.write() -= 1, "Down low!" }
     }