Struct Primitive

pub struct Primitive<T>(/* private fields */);

Shim for primitive types to efficiently implement Collapse.

Notes

This newtype is transparent. It is safe to mem::transmute() from Primitive<T> to T and vice versa. However, if T does not implement PrimitiveCollapse, it is undefined behaviour.

Also, the collapse() output from this structure is not guaranteed to be the same as the collapse() output from the inner value, so the following code is very unsafe and such patterns should only be used if the programmer is absolutely sure there will be absolutely no difference between T::collapse and Self::collapse:

 let mut map: Map<u8, ()> = Map::new();
 map.insert(120, ());

 let map: Map<Primitive<u8>, ()> = unsafe { mem::transmute(map) };
 assert_eq!(map.get(&120.into()).copied(), Some(()));

This code pretty much only works with u8. and i8.

However unsafe, it is possible these values will line up in your use case. In which case, it is an acceptable pattern.

Implementations

impl<T: PrimitiveCollapse + Eq> Primitive<T>

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

Wrap this primitive

pub fn into_inner(self) -> T

Consume into the inner primitive

pub fn inner(&self) -> &T

Get the inner primitive

Notes

Only useful if the inner type does not implement Copy, which is extremely unlickely. You should almost always use into_inner instead.

pub fn inner_mut(&mut self) -> &mut T

Get a mutable reference to the inner ptimitive.

pub const fn into_inner_copy(self) -> T

where T: Copy,

Same as into_inner, except only for Copy types.

Notes

The only use of this function is that it is const fn on nightly. If you’re not using a version of rustc that supports generic const fn, this method is identical to into_inner.

Trait Implementations

impl<T: Clone> Clone for Primitive<T>

fn clone(&self) -> Primitive<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: PrimitiveCollapse + Eq> Collapse for Primitive<T>

fn collapse(&self) -> u8

Create the index key for this instance. This is similar in use to Hash::hash().

impl<T: Debug> Debug for Primitive<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for Primitive<T>

fn default() -> Primitive<T>

Returns the “default value” for a type.

impl<T> From<T> for Primitive<T>

where T: PrimitiveCollapse + Eq,

fn from(from: T) -> Self

Converts to this type from the input type.

impl<T: Ord> Ord for Primitive<T>

fn cmp(&self, other: &Primitive<T>) -> 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> PartialEq for Primitive<T>

fn eq(&self, other: &Primitive<T>) -> 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> PartialOrd for Primitive<T>

fn partial_cmp(&self, other: &Primitive<T>) -> 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: Copy> Copy for Primitive<T>

impl<T: Eq> Eq for Primitive<T>

impl<T> StructuralPartialEq for Primitive<T>