Struct Argument

pub struct Argument<'a> { /* private fields */ }

A variant item that implements Copy-on-Write.

It acts similarly to a Cow, except for two things:

1. It is encapsulated, meaning that the inner contents cannot be accessed.
2. The storage is handled differently compared to Cow, which allows for a smaller type size.

Implementations

impl Argument<'_>

pub fn new_owned<T>(item: T) -> Self

where T: Any + Clone,

Creates a new owned Argument.

pub fn is_owned(&self) -> bool

Checks if the argument is owned.

pub fn is_borrowed(&self) -> bool

Checks if the argument is borrowed.

pub fn to_mut(&mut self) -> &mut dyn Any

Returns a mutable reference to the item itself.

If the inner contents are borrowed, this creates a new owned instance first before returning the reference itself.

pub fn to_owned(&self) -> Self

Clones the inner contents of the object, returning an owned argument.

pub fn downcast_owned<T>(self) -> Result<T, Self>

where T: Clone + Any,

Downcasts an owned argument into type T, returning a result.

Return values

Ok(T): The argument gets consumed and returns the inner contents. Err(Self): Either the argument is not of type T or the argument itself is not owned.

pub unsafe fn downcast_owned_unchecked<T>(self) -> T

where T: Clone + Any,

Downcasts an owned argument into type T, without any checks.

Safety

The argument must both be owned and of type T.

Panics

The function will panic if the argument itself is not owned.

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

where T: Any + Clone,

Downcasts the argument into a cloned object of type T.

Returns None if the object’s type is not T.

pub unsafe fn downcast_cloned_unchecked<T>(&self) -> T

where T: Any + Clone,

Downcasts the argument into a cloned object of T without checking it first.

Safety

Assumes that the contents are of type T.

impl<'a> Argument<'a>

pub fn new_borrowed<T>(item: &'a T) -> Self

where T: Any + Clone,

Creates a borrowed argument of item T.

pub fn as_ref(&'a self) -> Self

Creates a borrowed reference to the source argument.

pub fn into_inner(self) -> ArgumentKind<'a>

Consumes the argument itself, returning what kind of argument it is.

Trait Implementations

impl<'a> Clone for Argument<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Argument<'_>

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

Formats the value using the given formatter.

impl Deref for Argument<'_>

type Target = dyn Any

The resulting type after dereferencing.

fn deref(&self) -> &dyn Any

Dereferences the value.

impl Drop for Argument<'_>

fn drop(&mut self)

Executes the destructor for this type.