Enum Notice 

#[non_exhaustive]
pub enum Notice {
    Toast,
    Banner,
}

Something the app is telling the user, unprompted.

Two concepts, not one with a placement. They differ in more than where they sit: a toast is transient, stacked and self-dismissing, and a banner is persistent, in flow, one per region, and dismissed by fixing the condition it reports. Folding them into one member with a placement parameter would make lifetime, stacking and dismissal all placement-dependent, which is the description leaking renderer policy.

All three apps have banners: info_banner and warning_banner in audiofiles, five of them in goingson (sync, sync-result, vacation-day, timer-active, past-review), .update-banner in Balanced Breakfast. The two webview apps also have toasts. So neither member is speculative, and no app gains a concept it lacks except audiofiles, whose renderer may legitimately decline to draw a toast at all.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Toast

Transient, stacked, dismisses itself.

Banner

Persistent, in flow, one per region, dismissed by fixing the cause.

Implementations

impl Notice

pub const fn transient(self) -> bool

Whether it goes away on its own.

pub const fn fill(self) -> Fill

How it sits.

A toast floats above the page rather than resting on it, which is Fill::Overlay’s whole reason to exist. A banner is a card in the flow. Both are raised, and they are raised off different things.

Trait Implementations

impl Clone for Notice

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Notice

impl Debug for Notice

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Notice

impl Hash for Notice

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Notice

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Notice