Struct ArrayBuilder

pub struct ArrayBuilder<T, const N: usize> { /* private fields */ }

Build an array dynamically without heap allocations.

See module documentation for more.

Implementations

impl<T, const N: usize> ArrayBuilder<T, N>

pub const fn new() -> Self

Create a new, empty builder.

pub fn push(&mut self, item: T) -> &mut Self

Insert an item into the builder.

If the builder is already full, the item is immediately dropped.

pub fn build_pad(&mut self, item: T) -> Result<[T; N], Error>

where T: Clone,

Pad out the array, returning an Err if there were too many calls to Self::push. The builder remains unchanged in the Err case.

let arr = ArrayBuilder::<_, 3>::new().push("first").build_pad("padding").unwrap();
assert_eq!(arr, ["first", "padding", "padding"]);

ArrayBuilder::<_, 1>::new().push("first").push("too many now!").build_pad("").unwrap_err();

pub fn build_pad_truncate(&mut self, item: T) -> [T; N]

where T: Clone,

Pad out the array, ignoring if there were too many calls to Self::push. The builder is restored to an empty state.

let arr = ArrayBuilder::<_, 3>::new().push("first").build_pad_truncate("padding");
assert_eq!(arr, ["first", "padding", "padding"]);

let arr =
    ArrayBuilder::<_, 1>::new().push("first").push("too many now!").build_pad_truncate("");
assert_eq!(arr, ["first"]);

pub fn build_truncate(&mut self) -> Result<[T; N], Error>

Build the array, ignoring if there were too many calls to Self::push. The builder is restored to an empty state, and remains unchanged in the Err case.

let arr = ArrayBuilder::<_, 1>::new().push("first").push("ignored").build_truncate().unwrap();
assert_eq!(arr, ["first"]);

ArrayBuilder::<&str, 1>::new().build_truncate().unwrap_err();

pub fn build_exact(&mut self) -> Result<[T; N], Error>

Require exactly N calls to Self::push. The builder remains unchanged in the Err case.

ArrayBuilder::<_, 2>::new().push("too few").build_exact().unwrap_err();
ArrayBuilder::<_, 2>::new().push("way").push("too").push("many").build_exact().unwrap_err();
ArrayBuilder::<_, 2>::new().push("just").push("right").build_exact().unwrap();

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

Return the current collection of items in the array.

Does not include excess items.

pub fn as_mut_slice(&mut self) -> &mut [T]

Return the current collection of items in the array.

Does not include excess items.

Trait Implementations

impl<T: Clone, const N: usize> Clone for ArrayBuilder<T, N>

fn clone(&self) -> ArrayBuilder<T, N>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug, const N: usize> Debug for ArrayBuilder<T, N>

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

Formats the value using the given formatter.

impl<T: Default, const N: usize> Default for ArrayBuilder<T, N>

fn default() -> ArrayBuilder<T, N>

Returns the “default value” for a type.

impl<T, const N: usize> Extend<T> for ArrayBuilder<T, N>

fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

Reserves capacity in a collection for the given number of additional elements.

impl<T, const N: usize> FromIterator<T> for ArrayBuilder<T, N>

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Creates a value from an iterator.

impl<T: Hash, const N: usize> Hash for ArrayBuilder<T, N>

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<T: Ord, const N: usize> Ord for ArrayBuilder<T, N>

fn cmp(&self, other: &ArrayBuilder<T, N>) -> 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.

impl<T: PartialEq, const N: usize> PartialEq for ArrayBuilder<T, N>

fn eq(&self, other: &ArrayBuilder<T, N>) -> 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<T: PartialOrd, const N: usize> PartialOrd for ArrayBuilder<T, N>

fn partial_cmp(&self, other: &ArrayBuilder<T, N>) -> 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<T: Eq, const N: usize> Eq for ArrayBuilder<T, N>

impl<T, const N: usize> StructuralPartialEq for ArrayBuilder<T, N>