Struct Baseline

pub struct Baseline(pub Option<UPx>);

The measurement from the top of the content to the bottom of the first line of text.

In typography, the baseline of text is where the font rendering begins drawing characters. Portions of characters may extend belown this measurement. For example, the letters yjg all have portions that extend below the baseline.

Tuple Fields

0: Option<UPx>

Implementations

impl Baseline

pub const NONE: Self

No baseline measurement.

pub fn map(self, map: impl FnOnce(UPx) -> UPx) -> Self

Apply map to the baseline, if present, and return the result.

If this baseline is None, map will not be invoked.

Methods from Deref<Target = Option<UPx>>

pub fn is_some(&self) -> bool

Returns true if the option is a Some value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_some(), true);

let x: Option<u32> = None;
assert_eq!(x.is_some(), false);

pub fn is_none(&self) -> bool

Returns true if the option is a None value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_none(), false);

let x: Option<u32> = None;
assert_eq!(x.is_none(), true);

pub fn as_ref(&self) -> Option<&T>

Converts from &Option<T> to Option<&T>.

Examples

Calculates the length of an Option<String> as an Option<usize> without moving the String. The map method takes the self argument by value, consuming the original, so this technique uses as_ref to first take an Option to a reference to the value inside the original.

let text: Option<String> = Some("Hello, world!".to_string());
// First, cast `Option<String>` to `Option<&String>` with `as_ref`,
// then consume *that* with `map`, leaving `text` on the stack.
let text_length: Option<usize> = text.as_ref().map(|s| s.len());
println!("still can print text: {text:?}");

pub fn as_pin_ref(self: Pin<&Option<T>>) -> Option<Pin<&T>>

Converts from Pin<&Option<T>> to Option<Pin<&T>>.

pub fn as_pin_mut(self: Pin<&mut Option<T>>) -> Option<Pin<&mut T>>

Converts from Pin<&mut Option<T>> to Option<Pin<&mut T>>.

pub fn as_slice(&self) -> &[T]

Returns a slice of the contained value, if any. If this is None, an empty slice is returned. This can be useful to have a single type of iterator over an Option or slice.

Note: Should you have an Option<&T> and wish to get a slice of T, you can unpack it via opt.map_or(&[], std::slice::from_ref).

Examples

assert_eq!(
    [Some(1234).as_slice(), None.as_slice()],
    [&[1234][..], &[][..]],
);

The inverse of this function is (discounting borrowing) [_]::first:

for i in [Some(1234_u16), None] {
    assert_eq!(i.as_ref(), i.as_slice().first());
}

pub fn as_deref(&self) -> Option<&<T as Deref>::Target>

where T: Deref,

Converts from Option<T> (or &Option<T>) to Option<&T::Target>.

Leaves the original Option in-place, creating a new one with a reference to the original one, additionally coercing the contents via Deref.

Examples

let x: Option<String> = Some("hey".to_owned());
assert_eq!(x.as_deref(), Some("hey"));

let x: Option<String> = None;
assert_eq!(x.as_deref(), None);

pub fn iter(&self) -> Iter<'_, T>

Returns an iterator over the possibly contained value.

Examples

let x = Some(4);
assert_eq!(x.iter().next(), Some(&4));

let x: Option<u32> = None;
assert_eq!(x.iter().next(), None);

Trait Implementations

impl Clone for Baseline

fn clone(&self) -> Baseline

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Baseline

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

Formats the value using the given formatter.

impl Default for Baseline

fn default() -> Baseline

Returns the “default value” for a type.

impl Deref for Baseline

type Target = Option<UPx>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl From<Option<Px>> for Baseline

fn from(value: Option<Px>) -> Self

Converts to this type from the input type.

impl From<Option<UPx>> for Baseline

fn from(value: Option<UPx>) -> Self

Converts to this type from the input type.

impl From<Px> for Baseline

fn from(value: Px) -> Self

Converts to this type from the input type.

impl From<UPx> for Baseline

fn from(value: UPx) -> Self

Converts to this type from the input type.

impl Ord for Baseline

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

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Baseline

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Baseline

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.

impl Round for Baseline

fn ceil(self) -> Self

Returns self raised to the next whole number further away from 0.

fn floor(self) -> Self

Returns self lowered to the next whole number closer to 0.

fn round(self) -> Self

Returns self rounded to the nearest whole number.

impl Copy for Baseline

impl Eq for Baseline

impl StructuralPartialEq for Baseline