Struct Lunit 

pub struct Lunit(/* private fields */);

Available on crate feature ui only.

▦ 🧱 📏 Fixed-point scalar used for UI layout negotiation.

---

^{📍 ui/layout::Lunit}

^{📦 size_of::<Lunit>() == 4 bytes / 32 bits ⚗️Option<T> ❗🟰 T}

---

Lunit is expressed in logical layout space. It is not a device pixel, physical pixel, terminal cell, typographic point, or real-world length.

Backend projection maps it to physical pixels, terminal cells, or other output units.

Implementations

impl Lunit

pub const CARRIER_BITS: u32 = i32::BITS

Number of bits in the primitive carrier.

pub const VALUE_BITS: u32

Number of bits used by the signed payload.

pub const META_BITS: u32

Number of high bits used by boundary metadata.

pub const DIR_BITS: u32 = 1

Number of metadata bits used by the boundary direction marker.

pub const COUNT_BITS: u32

Number of metadata bits used by the saturating boundary-event counter.

pub const MAX_COUNT: u32

Maximum representable boundary-event count.

pub const IS_SIGNED: bool = true

Whether the payload carrier is signed.

pub const IS_SYMMETRIC: bool = true

Whether the signed payload range is symmetric around zero.

pub const MIN_VALUE: i32 = Self::_MIN_VALUE

Minimum representable payload value.

pub const MAX_VALUE: i32 = Self::_MAX_VALUE

Maximum representable payload value.

pub const ZERO: Self

Zero, with empty metadata.

pub const MIN: Self

Minimum payload value, with empty metadata.

pub const MAX: Self

Maximum payload value, with empty metadata.

pub const fn new(value: i32) -> Self

Creates a value, saturating to the payload range.

If value is below MIN_VALUE, the result is clamped to MIN and records one lower-boundary event.

If value is above MAX_VALUE, the result is clamped to MAX and records one upper-boundary event.

pub const fn new_checked(value: i32) -> Option<Self>

Creates a value if it fits in the payload range.

pub const fn new_saturated(value: i32) -> Self

Creates a value saturated to the payload range.

pub const fn new_saturated_up(value: i64) -> Self

Creates a value saturated to the payload range, from an upcasted carrier.

pub const fn from_raw(raw: i32) -> Option<Self>

Creates a value from a raw encoded carrier.

Returns None if raw is reserved, invalid for the underlying representation, or decodes outside the payload range.

Non-canonical raw encodings with count == 0 are canonicalized so the direction bit is cleared.

pub const fn raw(self) -> i32

Returns the raw encoded carrier.

pub const fn get(self) -> i32

Returns the decoded payload value.

pub const fn is_bounded(self) -> bool

Returns whether this value carries at least one boundary event.

pub const fn bound_count(self) -> u32

Returns the saturating boundary-event count.

A value of 0 means no boundary event is recorded. When this is 0, bound_dir returns None.

pub const fn bound_dir(self) -> Option<Boundary1d>

Returns the last recorded boundary direction.

Returns None when bound_count is 0.

pub const fn clear_meta(self) -> Self

Returns the same payload value with empty metadata.

pub const fn with_bound_meta(self, count: u32, dir: Option<Boundary1d>) -> Self

Returns the same payload value with explicit boundary metadata.

count saturates to MAX_COUNT.

When count == 0, dir is ignored and the raw direction bit is canonicalized to zero.

pub const fn is_negative(self) -> bool

Whether the value is less than zero.

pub const fn is_positive(self) -> bool

Whether the value is greater than zero.

pub const fn is_zero(self) -> bool

Whether the value is zero.

pub const fn is_nonnegative(self) -> bool

Whether the value is greater than or equal to zero.

pub const fn is_nonpositive(self) -> bool

Whether the value is less than or equal to zero.

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

Equality comparison over decoded payload values.

pub const fn cmp(self, other: Self) -> Ordering

Compares decoded payload values.

pub const fn max(self, other: Self) -> Self

Returns the greater decoded value.

Metadata is cleared because the result is recomputed.

pub const fn max_meta(self, other: Self) -> Self

Returns the greater value, preserving the selected operand metadata.

pub const fn max_zero(self) -> Self

Returns the decoded value floored at zero.

Metadata is cleared because the result is recomputed.

pub const fn max_zero_meta(self) -> Self

Returns the decoded value floored at zero, preserving selected metadata.

pub const fn min(self, other: Self) -> Self

Returns the lesser decoded value.

Metadata is cleared because the result is recomputed.

pub const fn min_meta(self, other: Self) -> Self

Returns the lesser value, preserving the selected operand metadata.

pub const fn min_zero(self) -> Self

Returns the decoded value capped at zero.

Metadata is cleared because the result is recomputed.

pub const fn min_zero_meta(self) -> Self

Returns the decoded value capped at zero, preserving selected metadata.

pub const fn clamp(self, min: Self, max: Self) -> Self

Clamps the decoded value between min and max.

Metadata is cleared because the result is recomputed.

If min > max, this returns min.

pub const fn clamp_meta(self, min: Self, max: Self) -> Self

Clamps self between min and max, preserving selected metadata.

If min > max, this returns min.

impl Lunit

pub const QUANTA_PER_LOGICAL_PX: i32 = 120

Number of internal layout quanta per logical UI pixel.

pub const fn px(px: i32) -> Self

Creates a layout scalar from whole logical UI pixels.

Saturates if the scaled value escapes the payload range.

pub const fn px_frac(num: i32, den: i32) -> Self

Creates a layout scalar from a fraction of a logical UI pixel.

Rounds to the nearest representable quantum and saturates on overflow.

pub const fn from_quanta(quanta: i32) -> Self

Creates a layout scalar from internal layout quanta.

pub const fn quanta(self) -> i32

Returns the number of internal layout quanta.

pub const fn positive_part(self) -> Self

Returns this value clamped below by zero.

pub const fn sub_floor_zero(self, rhs: Self) -> Self

Subtracts rhs, returning zero instead of a negative result.

pub const fn div_floor_i32(self, rhs: i32) -> Self

Divides by an integer, rounding toward negative infinity.

Saturates to the signed endpoint if rhs == 0.

pub const fn div_ceil_i32(self, rhs: i32) -> Self

Divides by an integer, rounding toward positive infinity.

Saturates to the signed endpoint if rhs == 0.

pub const fn div_round_i32(self, rhs: i32) -> Self

Divides by an integer, rounding to the nearest result.

Halfway cases round away from zero. Saturates to the signed endpoint if rhs == 0.

pub const fn split_floor(self, parts: i32) -> Self

Returns the base part size when splitting this value into parts.

Returns zero if parts <= 0.

pub const fn split_remainder(self, parts: i32) -> i32

Returns the quantum remainder when splitting this value into parts.

Returns zero if parts <= 0.

impl Lunit

pub const fn abs(self) -> Self

Returns the absolute decoded value, saturating to the payload range.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn abs_meta(self) -> Self

Returns the absolute decoded value, preserving boundary metadata.

Inherited metadata is preserved; operation metadata is recorded if this clips.

pub const fn abs_nometa(self) -> Self

Returns the absolute decoded value without metadata.

No metadata is propagated or generated.

pub const fn sat_add(self, rhs: Self) -> Self

Saturating addition.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_add_meta(self, rhs: Self) -> Self

Saturating addition, preserving boundary metadata.

Inherited metadata is merged; operation metadata is recorded if this clips.

pub const fn sat_add_nometa(self, rhs: Self) -> Self

Saturating addition without metadata.

No metadata is propagated or generated.

pub const fn sat_add_floor_zero(self, rhs: Self) -> Self

Adds rhs, saturating to the payload range, then applying a zero floor.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_add_floor_zero_meta(self, rhs: Self) -> Self

Adds rhs, preserving metadata, saturating to the payload range, then applying a zero floor.

pub const fn sat_add_ceil_zero(self, rhs: Self) -> Self

Adds rhs, saturating to the payload range, then applying a zero ceiling.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_add_ceil_zero_meta(self, rhs: Self) -> Self

Adds rhs, preserving metadata, saturating to the payload range, then applying a zero ceiling.

pub const fn sat_sub(self, rhs: Self) -> Self

Saturating subtraction.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_sub_meta(self, rhs: Self) -> Self

Saturating subtraction, preserving boundary metadata.

Inherited metadata is merged; operation metadata is recorded if this clips.

pub const fn sat_sub_nometa(self, rhs: Self) -> Self

Saturating subtraction without metadata.

No metadata is propagated or generated.

pub const fn sat_sub_floor_zero(self, rhs: Self) -> Self

Subtracts rhs, saturating to the payload range, then applying a zero floor.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_sub_floor_zero_meta(self, rhs: Self) -> Self

Subtracts rhs, preserving metadata, saturating to the payload range, then applying a zero floor.

pub const fn sat_sub_ceil_zero(self, rhs: Self) -> Self

Subtracts rhs, saturating to the payload range, then applying a zero ceiling.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_sub_ceil_zero_meta(self, rhs: Self) -> Self

Subtracts rhs, preserving metadata, saturating to the payload range, then applying a zero ceiling.

pub const fn sat_mul(self, rhs: Self) -> Self

Saturating multiplication.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_mul_meta(self, rhs: Self) -> Self

Saturating multiplication, preserving boundary metadata.

Inherited metadata is merged; operation metadata is recorded if this clips.

pub const fn sat_mul_nometa(self, rhs: Self) -> Self

Saturating multiplication without metadata.

No metadata is propagated or generated.

pub const fn sat_mul_div(self, num: i32, den: i32) -> Option<Self>

Multiplies by num, divides by den, and saturates the final result.

Inherited metadata is ignored; operation metadata is recorded if this clips. Returns None when den == 0.

pub const fn sat_mul_div_meta(self, num: i32, den: i32) -> Option<Self>

Multiplies by num, divides by den, and saturates the final result, preserving boundary metadata.

Inherited metadata is merged; operation metadata is recorded if this clips. Returns None when den == 0.

pub const fn sat_mul_div_nometa(self, num: i32, den: i32) -> Option<Self>

Multiplies by num, divides by den, and saturates the final result without metadata.

No metadata is propagated or generated. Returns None when den == 0.

pub const fn sat_dist(self, rhs: Self) -> Self

Returns the absolute distance between decoded values, saturating to the payload range.

Inherited metadata is ignored; operation metadata is recorded if this clips.

pub const fn sat_dist_meta(self, rhs: Self) -> Self

Returns the absolute distance between decoded values, saturating to the payload range.

Inherited metadata is merged; operation metadata is recorded if this clips.

pub const fn sat_dist_nometa(self, rhs: Self) -> Self

Returns the absolute distance between decoded values, saturating to the payload range.

No metadata is propagated or generated.

impl Lunit

Checked operations

pub const fn che_add(self, rhs: Self) -> Option<Self>

Checked addition.

Inherited metadata is ignored. Returns None if the exact result escapes the payload range.

pub const fn che_add_meta(self, rhs: Self) -> Option<Self>

Checked addition, preserving boundary metadata.

Inherited metadata is merged when the result fits.

pub const fn che_sub(self, rhs: Self) -> Option<Self>

Checked subtraction.

Inherited metadata is ignored. Returns None if the exact result escapes the payload range.

pub const fn che_sub_meta(self, rhs: Self) -> Option<Self>

Checked subtraction, preserving boundary metadata.

Inherited metadata is merged when the result fits.

pub const fn che_mul(self, rhs: Self) -> Option<Self>

Checked multiplication.

Inherited metadata is ignored. Returns None if the exact result escapes the payload range.

pub const fn che_mul_meta(self, rhs: Self) -> Option<Self>

Checked multiplication, preserving boundary metadata.

Inherited metadata is merged when the result fits.

pub const fn che_mul_div(self, num: i32, den: i32) -> Option<Self>

Multiplies by num, divides by den, and checks the final result.

Inherited metadata is ignored. Returns None when den == 0 or the final result escapes the payload range.

pub const fn che_mul_div_meta(self, num: i32, den: i32) -> Option<Self>

Multiplies by num, divides by den, and checks the final result.

Inherited metadata is merged when the result fits. Returns None when den == 0 or the final result escapes the payload range.

pub const fn che_dist(self, rhs: Self) -> Option<Self>

Returns the absolute distance between the decoded values.

Returns None if the exact distance cannot be represented as a payload value.

pub const fn che_dist_meta(self, rhs: Self) -> Option<Self>

Returns the absolute distance between the decoded values.

Inherited metadata is merged when the result fits. Returns None if the exact distance cannot be represented as a payload value.

impl Lunit

Modular operations

pub const fn mod_add(self, delta: Self, modulo: Self) -> Option<Self>

Modular addition over an explicit positive modulus.

Returns (self + delta) mod modulo using Euclidean modulo.

Returns None when modulo <= 0.

pub const fn mod_sub(self, delta: Self, modulo: Self) -> Option<Self>

Modular subtraction over an explicit positive modulus.

Returns (self - delta) mod modulo using Euclidean modulo.

Returns None when modulo <= 0.

impl Lunit

Upcasted outcome operations

pub const fn add_up(self, rhs: Self) -> i64

Returns the exact upcasted sum of the decoded values.

pub const fn sub_up(self, rhs: Self) -> i64

Returns the exact upcasted difference of the decoded values.

pub const fn mul_up(self, rhs: Self) -> i64

Returns the exact upcasted product of the decoded values.

pub const fn dist_up(self, rhs: Self) -> i64

Returns the exact absolute distance between the decoded values.

Trait Implementations

impl Clone for Lunit

fn clone(&self) -> Lunit

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl ConstInit for Lunit

const INIT: Self = Self::ZERO

Returns the compile-time “initial value” for a type.

impl Copy for Lunit

impl Debug for Lunit

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

Formats the value using the given formatter.

impl Default for Lunit

fn default() -> Self

Returns the “default value” for a type.

impl Display for Lunit

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

Formats the value using the given formatter.

impl Eq for Lunit

impl Hash for Lunit

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 Ord for Lunit

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Lunit

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

Equality operator ==.

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

Inequality operator !=.

impl PartialEq<Lunit> for i32

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

Equality operator ==.

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

Inequality operator !=.

impl PartialEq<i32> for Lunit

fn eq(&self, other: &i32) -> bool

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Lunit

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.