std::rc::Rc - Rust (original) (raw)
Struct std::rc::Rc1.0.0 [−] [src]
pub struct Rc where
T: ?Sized, { /* fields omitted */ }
A single-threaded reference-counting pointer. 'Rc' stands for 'Reference Counted'.
See the module-level documentation for more details.
The inherent methods of Rc are all associated functions, which means that you have to call them as e.g. Rc::get_mut(&mut value) instead ofvalue.get_mut(). This avoids conflicts with methods of the inner type T.
impl<T> [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>[src]
pub fn [new](#method.new)(value: T) -> [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>[src]
Constructs a new Rc<T>.
use std::rc::Rc;
let five = Rc::new(5);Run
pub fn [try_unwrap](#method.try%5Funwrap)(this: [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [Result](../../std/result/enum.Result.html "enum std::result::Result")<T, [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>>
1.4.0
Returns the contained value, if the Rc has exactly one strong reference.
Otherwise, an Err is returned with the same Rc that was passed in.
This will succeed even if there are outstanding weak references.
use std::rc::Rc;
let x = Rc::new(3); assert_eq!(Rc::try_unwrap(x), Ok(3));
let x = Rc::new(4); let _y = Rc::clone(&x); assert_eq!(*Rc::try_unwrap(x).unwrap_err(), 4);Run
`impl Rc where
pub fn [into_raw](#method.into%5Fraw)(this: [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [*const T](../primitive.pointer.html)
1.17.0
Consumes the Rc, returning the wrapped pointer.
To avoid a memory leak the pointer must be converted back to an Rc usingRc::from_raw.
use std::rc::Rc;
let x = Rc::new(10); let x_ptr = Rc::into_raw(x); assert_eq!(unsafe { *x_ptr }, 10);Run
pub unsafe fn [from_raw](#method.from%5Fraw)(ptr: [*const T](../primitive.pointer.html)) -> [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>
1.17.0
Constructs an Rc from a raw pointer.
The raw pointer must have been previously returned by a call to aRc::into_raw.
This function is unsafe because improper use may lead to memory problems. For example, a double-free may occur if the function is called twice on the same raw pointer.
use std::rc::Rc;
let x = Rc::new(10); let x_ptr = Rc::into_raw(x);
unsafe {
let x = Rc::from_raw(x_ptr);
assert_eq!(*x, 10);}
pub fn [downgrade](#method.downgrade)(this: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [Weak](../../std/rc/struct.Weak.html "struct std::rc::Weak")<T>
1.4.0
Creates a new Weak pointer to this value.
use std::rc::Rc;
let five = Rc::new(5);
let weak_five = Rc::downgrade(&five);Run
pub fn [weak_count](#method.weak%5Fcount)(this: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [usize](../primitive.usize.html)
1.15.0
Gets the number of Weak pointers to this value.
use std::rc::Rc;
let five = Rc::new(5); let _weak_five = Rc::downgrade(&five);
assert_eq!(1, Rc::weak_count(&five));Run
pub fn [strong_count](#method.strong%5Fcount)(this: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [usize](../primitive.usize.html)
1.15.0
Gets the number of strong (Rc) pointers to this value.
use std::rc::Rc;
let five = Rc::new(5); let _also_five = Rc::clone(&five);
assert_eq!(2, Rc::strong_count(&five));Run
pub fn [get_mut](#method.get%5Fmut)(this: &mut [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[&mut ](../primitive.reference.html)T>
1.4.0
Returns a mutable reference to the inner value, if there are no other Rc or Weak pointers to the same value.
Returns None otherwise, because it is not safe to mutate a shared value.
See also make_mut, which will clonethe inner value when it's shared.
use std::rc::Rc;
let mut x = Rc::new(3); *Rc::get_mut(&mut x).unwrap() = 4; assert_eq!(*x, 4);
let _y = Rc::clone(&x); assert!(Rc::get_mut(&mut x).is_none());Run
pub fn [ptr_eq](#method.ptr%5Feq)(this: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)
1.17.0
Returns true if the two Rcs point to the same value (not just values that compare as equal).
use std::rc::Rc;
let five = Rc::new(5); let same_five = Rc::clone(&five); let other_five = Rc::new(5);
assert!(Rc::ptr_eq(&five, &same_five)); assert!(!Rc::ptr_eq(&five, &other_five));Run
`impl Rc where
pub fn [make_mut](#method.make%5Fmut)(this: &mut [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [&mut ](../primitive.reference.html)T
1.4.0
Makes a mutable reference into the given Rc.
If there are other Rc or Weak pointers to the same value, then make_mut will invoke clone on the inner value to ensure unique ownership. This is also referred to as clone-on-write.
See also get_mut, which will fail rather than cloning.
use std::rc::Rc;
let mut data = Rc::new(5);
*Rc::make_mut(&mut data) += 1;
let mut other_data = Rc::clone(&data);
*Rc::make_mut(&mut data) += 1;
*Rc::make_mut(&mut data) += 1;
*Rc::make_mut(&mut other_data) *= 2;
assert_eq!(*data, 8); assert_eq!(*other_data, 12);Run
impl [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[Any](../../std/any/trait.Any.html "trait std::any::Any") + 'static>[src]
`pub fn downcast(self) -> Result<Rc, Rc<Any + 'static>> where
🔬 This is a nightly-only experimental API. (rc_downcast #44608)
Attempt to downcast the Rc<Any> to a concrete type.
#![feature(rc_downcast)] use std::any::Any; use std::rc::Rc;
fn print_if_string(value: Rc) { if let Ok(string) = value.downcast::() { println!("String ({}): {}", string.len(), string); } }
fn main() { let my_string = "Hello World".to_string(); print_if_string(Rc::new(my_string)); print_if_string(Rc::new(0i8)); }Run
`impl<T, U> CoerceUnsized<Rc> for Rc where
T: Unsize + ?Sized,
U: ?Sized, `[src]
`impl 
for Rc where
impl<'a> [From](../../std/convert/trait.From.html "trait std::convert::From")<&'a [str](../primitive.str.html)> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[str](../primitive.str.html)>
1.21.0
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[String](../../std/string/struct.String.html "struct std:🧵:String")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[str](../primitive.str.html)>
1.21.0
`impl From<Box> for Rc where
T: ?Sized, `
1.21.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<T> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>
1.6.0
`impl<'a, T> From<&'a [T]> for Rc<T[]> where
T: Clone, `
1.21.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>
1.21.0
`impl Borrow for Rc where
`impl Ord for Rc where
fn [cmp](../../std/cmp/trait.Ord.html#tymethod.cmp)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [Ordering](../../std/cmp/enum.Ordering.html "enum std::cmp::Ordering")[src]
Comparison for two Rcs.
The two are compared by calling cmp() on their inner values.
use std::rc::Rc; use std::cmp::Ordering;
let five = Rc::new(5);
assert_eq!(Ordering::Less, five.cmp(&Rc::new(6)));Run
fn [max](../../std/cmp/trait.Ord.html#method.max)(self, other: Self) -> Self
1.21.0
Compares and returns the maximum of two values. Read more
fn [min](../../std/cmp/trait.Ord.html#method.min)(self, other: Self) -> Self
1.21.0
Compares and returns the minimum of two values. Read more
`impl Clone for Rc where
fn [clone](../../std/clone/trait.Clone.html#tymethod.clone)(&self) -> [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>[src]
Makes a clone of the Rc pointer.
This creates another pointer to the same inner value, increasing the strong reference count.
use std::rc::Rc;
let five = Rc::new(5);
Rc::clone(&five);Run
fn [clone_from](../../std/clone/trait.Clone.html#method.clone%5Ffrom)(&mut self, source: [&](../primitive.reference.html)Self)[src]
Performs copy-assignment from source. Read more
`impl Hash for Rc where
`impl PartialEq<Rc> for Rc where
fn [eq](../../std/cmp/trait.PartialEq.html#tymethod.eq)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
Equality for two Rcs.
Two Rcs are equal if their inner values are equal.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five == Rc::new(5));Run
fn [ne](../../std/cmp/trait.PartialEq.html#method.ne)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
Inequality for two Rcs.
Two Rcs are unequal if their inner values are unequal.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five != Rc::new(6));Run
`impl Display for Rc where
`impl Eq for Rc where
`impl AsRef for Rc where
T: ?Sized, `
1.5.0
`impl Default for Rc where
fn [default](../../std/default/trait.Default.html#tymethod.default)() -> [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>[src]
Creates a new Rc<T>, with the Default value for T.
use std::rc::Rc;
let x: Rc = Default::default(); assert_eq!(*x, 0);Run
`impl Debug for Rc where
`impl Deref for Rc where
type [Target](../../std/ops/trait.Deref.html#associatedtype.Target) = T
The resulting type after dereferencing.
fn [deref](../../std/ops/trait.Deref.html#tymethod.deref)(&self) -> [&](../primitive.reference.html)T[src]
Dereferences the value.
`impl PartialOrd<Rc> for Rc where
T: PartialOrd + ?Sized, `[src]
fn [partial_cmp](../../std/cmp/trait.PartialOrd.html#tymethod.partial%5Fcmp)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[Ordering](../../std/cmp/enum.Ordering.html "enum std::cmp::Ordering")>[src]
Partial comparison for two Rcs.
The two are compared by calling partial_cmp() on their inner values.
use std::rc::Rc; use std::cmp::Ordering;
let five = Rc::new(5);
assert_eq!(Some(Ordering::Less), five.partial_cmp(&Rc::new(6)));Run
fn [lt](../../std/cmp/trait.PartialOrd.html#method.lt)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
Less-than comparison for two Rcs.
The two are compared by calling < on their inner values.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five < Rc::new(6));Run
fn [le](../../std/cmp/trait.PartialOrd.html#method.le)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
'Less than or equal to' comparison for two Rcs.
The two are compared by calling <= on their inner values.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five <= Rc::new(5));Run
fn [gt](../../std/cmp/trait.PartialOrd.html#method.gt)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
Greater-than comparison for two Rcs.
The two are compared by calling > on their inner values.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five > Rc::new(4));Run
fn [ge](../../std/cmp/trait.PartialOrd.html#method.ge)(&self, other: &[Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>) -> [bool](../primitive.bool.html)[src]
'Greater than or equal to' comparison for two Rcs.
The two are compared by calling >= on their inner values.
use std::rc::Rc;
let five = Rc::new(5);
assert!(five >= Rc::new(5));Run
`impl Pointer for Rc where
`impl Drop for Rc where
fn [drop](../../std/ops/trait.Drop.html#tymethod.drop)(&mut self)[src]
Drops the Rc.
This will decrement the strong reference count. If the strong reference count reaches zero then the only other references (if any) areWeak, so we drop the inner value.
use std::rc::Rc;
struct Foo;
impl Drop for Foo { fn drop(&mut self) { println!("dropped!"); } }
let foo = Rc::new(Foo); let foo2 = Rc::clone(&foo);
drop(foo);
drop(foo2); Run
`impl 
for Rc where
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[CString](../../std/ffi/struct.CString.html "struct std::ffi::CString")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[CStr](../../std/ffi/struct.CStr.html "struct std::ffi::CStr")>
1.24.0
impl<'a> [From](../../std/convert/trait.From.html "trait std::convert::From")<&'a [CStr](../../std/ffi/struct.CStr.html "struct std::ffi::CStr")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[CStr](../../std/ffi/struct.CStr.html "struct std::ffi::CStr")>
1.24.0
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[OsString](../../std/ffi/struct.OsString.html "struct std::ffi::OsString")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[OsStr](../../std/ffi/struct.OsStr.html "struct std::ffi::OsStr")>
1.24.0
impl<'a> [From](../../std/convert/trait.From.html "trait std::convert::From")<&'a [OsStr](../../std/ffi/struct.OsStr.html "struct std::ffi::OsStr")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[OsStr](../../std/ffi/struct.OsStr.html "struct std::ffi::OsStr")>
1.24.0
impl<T: [RefUnwindSafe](../../std/panic/trait.RefUnwindSafe.html "trait std::panic::RefUnwindSafe") + ?[Sized](../../std/marker/trait.Sized.html "trait std:📑:Sized")> [UnwindSafe](../../std/panic/trait.UnwindSafe.html "trait std::panic::UnwindSafe") for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<T>
1.9.0
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[PathBuf](../../std/path/struct.PathBuf.html "struct std::path::PathBuf")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[Path](../../std/path/struct.Path.html "struct std::path::Path")>
1.24.0
impl<'a> [From](../../std/convert/trait.From.html "trait std::convert::From")<&'a [Path](../../std/path/struct.Path.html "struct std::path::Path")> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[Path](../../std/path/struct.Path.html "struct std::path::Path")>
1.24.0