Add a pure now helper to time module

src/time.rs

@@ -11,3 +11,17 @@ pub use crate::core::time::*;
     )))
 )]
 pub use iced_futures::backend::default::time::*;
+
+use crate::Task;
+
+/// Returns a [`Task`] that produces the current [`Instant`]
+/// by calling [`Instant::now`].
+///
+/// While you can call [`Instant::now`] directly in your application,
+/// this is an "impure" operation (i.e. it's not referentially transparent).
+///
+/// You may care about purity if you want to leverage the `time-travel`
+/// feature properly.
+pub fn now() -> Task<Instant> {
+    Task::future(async { Instant::now() })
+}