Enum abi_stable::std_types::cow::RCow

#[repr(C)]pub enum RCow<'a, B: ?Sized> where
    B: BorrowOwned<'a>,  {
    Borrowed(<B as BorrowOwned<'a>>::RBorrowed),
    Owned(<B as BorrowOwned<'a>>::ROwned),
}

Ffi-safe equivalent of ::std::borrow::Cow.

The most common examples of this type are:

• RCow<'_,str>: contains an RStr<'_> or an RString.

• RCow<'_,[T]>: contains an RSlice<'_,T> or an RVec.

• RCow<'_,T>: contains a &T or a T.

Example

Using a RCow<'a,str>.

This implements a solution to the well known fizzbuzz problem.

use abi_stable::std_types::RCow;

fn fizzbuzz(n:u32)->RCow<'static,str>{
    match (n%3,n%5) {
        (0,0)=>RCow::from("FizzBuzz"),
        (0,_)=>RCow::from("Fizz"),
        (_,0)=>RCow::from("Buzz"),
        (_,_)=>RCow::from(n.to_string()),
    }
}

for n in 1..=100{
    println!("{}",fizzbuzz(n));
}

Note:this example allocates when the number is neither a multiple of 5 or 3.

Variants

Borrowed(<B as BorrowOwned<'a>>::RBorrowed)

Owned(<B as BorrowOwned<'a>>::ROwned)

Implementations

impl<'a, B: ?Sized> RCow<'a, B> where
    B: BorrowOwned<'a>, 

pub fn to_mut(&mut self) -> &mut B::ROwned

Get a mutable reference to the owner form of RCow, converting to the owned form if it is currently the borrowed form.

Examples

use abi_stable::std_types::RCow;
 
let mut cow:RCow<'_,str>=RCow::from("Hello");
 
assert_eq!(&*cow,"Hello");
assert!(cow.is_borrowed());
 
cow.to_mut().push_str(", world!");
 
assert!(cow.is_owned());
assert_eq!(cow,RCow::from("Hello, world!"));
 

pub fn into_owned(self) -> B::ROwned

Unwraps into the owned owner form of RCow, converting to the owned form if it is currently the borrowed form.

Examples

use abi_stable::std_types::RCow;
 
let mut cow:RCow<'_,str>=RCow::from("Hello");

assert_eq!(&*cow,"Hello");
 
let mut buff=cow.into_owned();
buff.push_str(", world!");
 
assert_eq!(&*buff,"Hello, world!");
 

pub fn borrowed<'b: 'a>(&'b self) -> <B as BorrowOwned<'b>>::RBorrowed

Gets the contents of the RCow casted to the borrowed variant.

Examples

use abi_stable::std_types::{RCow,RSlice};
{
    let cow:RCow<'_,[u8]>=RCow::from(&[0,1,2,3][..]);
    assert_eq!( cow.borrowed(), RSlice::from_slice(&[0,1,2,3]) );
}
{
    let cow:RCow<'_,[u8]>=RCow::from(vec![0,1,2,3]);
    assert_eq!( cow.borrowed(), RSlice::from_slice(&[0,1,2,3]) );
}

pub fn is_borrowed(&self) -> bool

Whether this is a borrowing RCow.

Examples

use abi_stable::std_types::RCow;
 
{
    let cow:RCow<'_,[u8]>=RCow::from(&[0,1,2,3][..]);
    assert!( cow.is_borrowed() );
}
{
    let cow:RCow<'_,[u8]>=RCow::from(vec![0,1,2,3]);
    assert!( !cow.is_borrowed() );
}
 

pub fn is_owned(&self) -> bool

Whether this is an owning RCow.

Examples

use abi_stable::std_types::RCow;
 
let cow:RCow<'_,[u8]>=RCow::from(&[0,1,2,3][..]);
assert!( !cow.is_owned() );
 
let cow:RCow<'_,[u8]>=RCow::from(vec![0,1,2,3]);
assert!( cow.is_owned() );
 

impl<'a, T> RCow<'a, [T]> where
    T: Clone, 

pub fn from_slice(this: &'a [T]) -> Self

For converting a &'a [T] to an RCow<'a,[T]>, most useful when converting from &'a [T;N] because it coerces the array to a slice.

Trait Implementations

impl<'a, B: ?Sized> AsRef<B> for RCow<'a, B> where
    B: BorrowOwned<'a>, 

fn as_ref(&self) -> &B

Performs the conversion.

impl<'a, B: ?Sized> Borrow<B> for RCow<'a, B> where
    B: BorrowOwned<'a>, 

fn borrow(&self) -> &B

Immutably borrows from an owned value.

impl<'a, B: ?Sized> Clone for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B::ROwned: Clone, 

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a, B: ?Sized> Copy for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B::ROwned: Copy, 

impl<'a, B: ?Sized> Debug for RCow<'a, B> where
    B: Debug,
    B: BorrowOwned<'a>, 

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

Formats the value using the given formatter.

impl<'a, B: ?Sized> Deref for RCow<'a, B> where
    B: BorrowOwned<'a>, 

type Target = B

The resulting type after dereferencing.

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

Dereferences the value.

impl<'de, 'a, T> Deserialize<'de> for RCow<'a, [T]> where
    T: Clone + Deserialize<'de>, 

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de, 'a> Deserialize<'de> for RCow<'a, str>

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de, 'a, T> Deserialize<'de> for RCow<'a, T> where
    T: Clone + Deserialize<'de>, 

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'a, B: ?Sized> Display for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B: Display, 

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

Formats the value using the given formatter.

impl<'a, B: ?Sized> Eq for RCow<'a, B> where
    B: Eq,
    B: BorrowOwned<'a>, 

impl<'a, T> From<&'a [T]> for RCow<'a, [T]> where
    T: Clone, 

fn from(this: &'a [T]) -> Self

Performs the conversion.

impl<'a> From<&'a RString> for RCow<'a, str>

fn from(this: &'a RString) -> Self

Performs the conversion.

impl<'a> From<&'a String> for RCow<'a, str>

fn from(this: &'a String) -> Self

Performs the conversion.

impl<'a> From<&'a str> for RCow<'a, str>

fn from(this: &'a str) -> Self

Performs the conversion.

impl<'a, B: ?Sized> From<Cow<'a, B>> for RCow<'a, B> where
    B: BorrowOwned<'a>, 

fn from(this: Cow<'a, B>) -> RCow<'a, B>

Performs the conversion.

impl<'a, T> From<RSlice<'a, T>> for RCow<'a, [T]> where
    T: Clone, 

fn from(this: RSlice<'a, T>) -> Self

Performs the conversion.

impl<'a> From<RStr<'a>> for RCow<'a, str>

fn from(this: RStr<'a>) -> Self

Performs the conversion.

impl<'a> From<RString> for RCow<'a, str>

fn from(this: RString) -> Self

Performs the conversion.

impl<'a, T> From<RVec<T>> for RCow<'a, [T]> where
    T: Clone, 

fn from(this: RVec<T>) -> Self

Performs the conversion.

impl<'a> From<String> for RCow<'a, str>

fn from(this: String) -> Self

Performs the conversion.

impl<'a, T> From<Vec<T>> for RCow<'a, [T]> where
    T: Clone, 

fn from(this: Vec<T>) -> Self

Performs the conversion.

impl<'a, B: ?Sized> GetStaticEquivalent_ for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B: __GetStaticEquivalent_,
    <B as BorrowOwned<'a>>::RBorrowed: StableAbi,
    <B as BorrowOwned<'a>>::ROwned: StableAbi, 

type StaticEquivalent = _static_RCow<'static, __GetStaticEquivalent<B>>

impl<'a, B: ?Sized> Hash for RCow<'a, B> where
    B: Hash,
    B: BorrowOwned<'a>, 

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<'a, B: ?Sized> Into<Cow<'a, B>> for RCow<'a, B> where
    B: BorrowOwned<'a>, 

fn into(self) -> Cow<'a, B>

Performs the conversion.

impl<'a, B: ?Sized> IntoReprRust for RCow<'a, B> where
    B: BorrowOwned<'a>, 

type ReprRust = Cow<'a, B>

fn into_rust(self) -> Self::ReprRust

impl<'a, B: ?Sized> Ord for RCow<'a, B> where
    B: Ord,
    B: BorrowOwned<'a>, 

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

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

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

Restrict a value to a certain interval.

impl<'a, B: ?Sized> PartialEq<RCow<'a, B>> for RCow<'a, B> where
    B: PartialEq,
    B: BorrowOwned<'a>, 

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a, B: ?Sized> PartialOrd<RCow<'a, B>> for RCow<'a, B> where
    B: PartialOrd,
    B: BorrowOwned<'a>, 

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a, B: ?Sized> Serialize for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B: Serialize, 

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<'a, B: ?Sized> SharedStableAbi for RCow<'a, B> where
    B: BorrowOwned<'a>,
    B: __GetStaticEquivalent_,
    <B as BorrowOwned<'a>>::RBorrowed: StableAbi,
    <B as BorrowOwned<'a>>::ROwned: StableAbi, 

type IsNonZeroType = False

Whether this type has a single invalid bit-pattern.

type Kind = __ValueKind

The kind of abi stability of this type,there are 2:

const S_LAYOUT: &'static TypeLayout

The layout of the type provided by implementors.

const S_ABI_CONSTS: AbiConsts