Enum Radius 

pub enum Radius {
    Square,
    Fine,
    Control,
    Panel,
    Round,
}

How rounded a corner is, named for what the corner belongs to.

The third axis to make the same move as Gap and Text: name the thing and let the value follow. Whether a corner should be 3px or 4px is unanswerable in isolation, and answering it once per component is how a stylesheet ends up with 2, 3, 4, 6, 8 and 12 all meaning “slightly rounded”.

Rounding is an affordance

The scale is deliberately short, because a corner radius carries one bit of meaning: whether the thing is meant to be pressed. Self::Square exists as a named rung rather than as the absence of a radius so that a container states that it is square, and a reader can tell a deliberate zero from a rule nobody wrote.

Variants

Square

No rounding. Containers: cards, panels, dropdowns, page shells.

Fine

An eighth of the base. The tightest corner still visible: inline code, small badges, status chips.

Control

A quarter of the base. Controls: buttons, inputs, selects.

Panel

Half the base. Surfaces that round rather than sit square: media covers, callout boxes, feature cards.

Round

A circle, whatever the element’s size.

Implementations

impl Radius

pub const fn ratio(self) -> Option<Ratio>

This corner as a fraction of the base unit.

Self::Round has none, and that is not an oversight: 50% is a proportion of the element’s own box rather than of the base, so it does not scale with --geometry-base and cannot be written as a Ratio. Use Self::css, which spells every rung.

pub const fn px(self) -> Option<u16>

Size in CSS pixels at the default base, or None for Self::Round.

pub fn css(self) -> String

The CSS value for this rung.

Square emits a bare 0 rather than a calc() that multiplies the base by nothing, and Round emits the percentage.

pub const fn token(self) -> &'static str

The CSS custom-property name, without the leading --.

pub const fn all() -> [Self; 5]

Every rung, squarest first.

Trait Implementations

impl Clone for Radius

fn clone(&self) -> Radius

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Radius

impl Debug for Radius

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

Formats the value using the given formatter.

impl Eq for Radius

impl Hash for Radius

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 Radius

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Radius