Struct NonMaxU32

pub struct NonMaxU32(NonZeroU32);

An unsigned 32-bit value known not to be u32::MAX.

A NonMaxU32 value can represent any value in the range 0 .. u32::MAX - 1, and an Option<NonMaxU32> is still a 32-bit value. In other words, NonMaxU32 is just like NonZeroU32, except that a different value is missing from the full u32 range.

Since zero is a very useful value in indexing, NonMaxU32 is more useful for representing indices than NonZeroU32.

NonMaxU32 values and Option<NonMaxU32> values both occupy 32 bits.

Serialization and Deserialization

When the appropriate Cargo features are enabled, NonMaxU32 implements [serde::Serialize] and [serde::Deserialize] in the natural way, as the integer value it represents. For example, serializing NonMaxU32::new(0).unwrap() as JSON or RON yields the string "0". This is the case despite NonMaxU32’s implementation, described below.

Implementation

Although this should not be observable to its users, a NonMaxU32 whose value is n is a newtype around a NonZeroU32 whose value is n + 1. This way, the range of values that NonMaxU32 can represent, `0..=u32::MAX

• 1, is mapped to the range 1..=u32::MAX, which is the range that [NonZeroU32] can represent. (And conversely, since [u32] addition wraps around, the value unrepresentable in NonMaxU32, [u32::MAX], becomes the value unrepresentable in [NonZeroU32], 0`.)

Tuple Fields

0: NonZeroU32

Implementations

impl NonMaxU32

pub const fn new(n: u32) -> Option<Self>

Construct a NonMaxU32 whose value is n, if possible.

pub const fn get(self) -> u32

Return the value of self as a u32.

pub const unsafe fn new_unchecked(n: u32) -> NonMaxU32

Construct a NonMaxU32 whose value is n.

Safety

The value of n must not be u32::MAX.

pub const unsafe fn from_usize_unchecked(index: usize) -> Self

Construct a NonMaxU32 whose value is index.

Safety

• The value of index must be strictly less than u32::MAX.

pub fn checked_add(self, n: u32) -> Option<Self>

Trait Implementations

impl Clone for NonMaxU32

fn clone(&self) -> NonMaxU32

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for NonMaxU32

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

Formats the value using the given formatter.

impl Display for NonMaxU32

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

Formats the value using the given formatter.

impl Hash for NonMaxU32

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 NonMaxU32

fn cmp(&self, other: &NonMaxU32) -> 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 PartialEq for NonMaxU32

fn eq(&self, other: &NonMaxU32) -> 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 NonMaxU32

fn partial_cmp(&self, other: &NonMaxU32) -> 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 Copy for NonMaxU32

impl Eq for NonMaxU32

impl StructuralPartialEq for NonMaxU32