Trait kvarn::prelude::utils::prelude::compact_str::core::any::Any

1.0.0 · source ·
pub trait Any: 'static {
    // Required method
    fn type_id(&self) -> TypeId;
}
Expand description

A trait to emulate dynamic typing.

Most types implement Any. However, any type which contains a non-'static reference does not. See the module-level documentation for more details.

Required Methods§

1.34.0 · source

fn type_id(&self) -> TypeId

Gets the TypeId of self.

If called on a dyn Any trait object (or a trait object of a subtrait of Any), this returns the TypeId of the underlying concrete type, not that of dyn Any itself.

§Examples
use std::any::{Any, TypeId};

fn is_string(s: &dyn Any) -> bool {
    TypeId::of::<String>() == s.type_id()
}

assert_eq!(is_string(&0), false);
assert_eq!(is_string(&"cookie monster".to_string()), true);

Implementations§

source§

impl<A> Box<dyn Any, A>
where A: Allocator,

1.0.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any, A>>
where T: Any,

Available on crate feature handover only.

Attempt to downcast the box to a concrete type.

§Examples
use std::any::Any;

fn print_if_string(value: Box<dyn Any>) {
    if let Ok(string) = value.downcast::<String>() {
        println!("String ({}): {}", string.len(), string);
    }
}

let my_string = "Hello World".to_string();
print_if_string(Box::new(my_string));
print_if_string(Box::new(0i8));
source

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A>
where T: Any,

🔬This is a nightly-only experimental API. (downcast_unchecked)
Available on crate feature handover only.

Downcasts the box to a concrete type.

For a safe alternative see downcast.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}
§Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

source§

impl<A> Box<dyn Any + Send, A>
where A: Allocator,

1.0.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + Send, A>>
where T: Any,

Available on crate feature handover only.

Attempt to downcast the box to a concrete type.

§Examples
use std::any::Any;

fn print_if_string(value: Box<dyn Any + Send>) {
    if let Ok(string) = value.downcast::<String>() {
        println!("String ({}): {}", string.len(), string);
    }
}

let my_string = "Hello World".to_string();
print_if_string(Box::new(my_string));
print_if_string(Box::new(0i8));
source

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A>
where T: Any,

🔬This is a nightly-only experimental API. (downcast_unchecked)
Available on crate feature handover only.

Downcasts the box to a concrete type.

For a safe alternative see downcast.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any + Send> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}
§Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

source§

impl<A> Box<dyn Any + Sync + Send, A>
where A: Allocator,

1.51.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + Sync + Send, A>>
where T: Any,

Available on crate feature handover only.

Attempt to downcast the box to a concrete type.

§Examples
use std::any::Any;

fn print_if_string(value: Box<dyn Any + Send + Sync>) {
    if let Ok(string) = value.downcast::<String>() {
        println!("String ({}): {}", string.len(), string);
    }
}

let my_string = "Hello World".to_string();
print_if_string(Box::new(my_string));
print_if_string(Box::new(0i8));
source

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A>
where T: Any,

🔬This is a nightly-only experimental API. (downcast_unchecked)
Available on crate feature handover only.

Downcasts the box to a concrete type.

For a safe alternative see downcast.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any + Send + Sync> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}
§Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

source§

impl dyn Any

1.0.0 · source

pub fn is<T>(&self) -> bool
where T: Any,

Returns true if the inner type is the same as T.

§Examples
use std::any::Any;

fn is_string(s: &dyn Any) {
    if s.is::<String>() {
        println!("It's a string!");
    } else {
        println!("Not a string...");
    }
}

is_string(&0);
is_string(&"cookie monster".to_string());
1.0.0 · source

pub fn downcast_ref<T>(&self) -> Option<&T>
where T: Any,

Returns some reference to the inner value if it is of type T, or None if it isn’t.

§Examples
use std::any::Any;

fn print_if_string(s: &dyn Any) {
    if let Some(string) = s.downcast_ref::<String>() {
        println!("It's a string({}): '{}'", string.len(), string);
    } else {
        println!("Not a string...");
    }
}

print_if_string(&0);
print_if_string(&"cookie monster".to_string());
1.0.0 · source

pub fn downcast_mut<T>(&mut self) -> Option<&mut T>
where T: Any,

Returns some mutable reference to the inner value if it is of type T, or None if it isn’t.

§Examples
use std::any::Any;

fn modify_if_u32(s: &mut dyn Any) {
    if let Some(num) = s.downcast_mut::<u32>() {
        *num = 42;
    }
}

let mut x = 10u32;
let mut s = "starlord".to_string();

modify_if_u32(&mut x);
modify_if_u32(&mut s);

assert_eq!(x, 42);
assert_eq!(&s, "starlord");
source

pub unsafe fn downcast_ref_unchecked<T>(&self) -> &T
where T: Any,

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

Returns a reference to the inner value as type dyn T.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_ref_unchecked::<usize>(), 1);
}
§Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

source

pub unsafe fn downcast_mut_unchecked<T>(&mut self) -> &mut T
where T: Any,

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

Returns a mutable reference to the inner value as type dyn T.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let mut x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    *x.downcast_mut_unchecked::<usize>() += 1;
}

assert_eq!(*x.downcast_ref::<usize>().unwrap(), 2);
§Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

source§

impl dyn Any + Send

1.0.0 · source

pub fn is<T>(&self) -> bool
where T: Any,

Forwards to the method defined on the type dyn Any.

§Examples
use std::any::Any;

fn is_string(s: &(dyn Any + Send)) {
    if s.is::<String>() {
        println!("It's a string!");
    } else {
        println!("Not a string...");
    }
}

is_string(&0);
is_string(&"cookie monster".to_string());
1.0.0 · source

pub fn downcast_ref<T>(&self) -> Option<&T>
where T: Any,

Forwards to the method defined on the type dyn Any.

§Examples
use std::any::Any;

fn print_if_string(s: &(dyn Any + Send)) {
    if let Some(string) = s.downcast_ref::<String>() {
        println!("It's a string({}): '{}'", string.len(), string);
    } else {
        println!("Not a string...");
    }
}

print_if_string(&0);
print_if_string(&"cookie monster".to_string());
1.0.0 · source

pub fn downcast_mut<T>(&mut self) -> Option<&mut T>
where T: Any,

Forwards to the method defined on the type dyn Any.

§Examples
use std::any::Any;

fn modify_if_u32(s: &mut (dyn Any + Send)) {
    if let Some(num) = s.downcast_mut::<u32>() {
        *num = 42;
    }
}

let mut x = 10u32;
let mut s = "starlord".to_string();

modify_if_u32(&mut x);
modify_if_u32(&mut s);

assert_eq!(x, 42);
assert_eq!(&s, "starlord");
source

pub unsafe fn downcast_ref_unchecked<T>(&self) -> &T
where T: Any,

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

Forwards to the method defined on the type dyn Any.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_ref_unchecked::<usize>(), 1);
}
§Safety

Same as the method on the type dyn Any.

source

pub unsafe fn downcast_mut_unchecked<T>(&mut self) -> &mut T
where T: Any,

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

Forwards to the method defined on the type dyn Any.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let mut x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    *x.downcast_mut_unchecked::<usize>() += 1;
}

assert_eq!(*x.downcast_ref::<usize>().unwrap(), 2);
§Safety

Same as the method on the type dyn Any.

source§

impl dyn Any + Sync + Send

1.28.0 · source

pub fn is<T>(&self) -> bool
where T: Any,

Forwards to the method defined on the type Any.

§Examples
use std::any::Any;

fn is_string(s: &(dyn Any + Send + Sync)) {
    if s.is::<String>() {
        println!("It's a string!");
    } else {
        println!("Not a string...");
    }
}

is_string(&0);
is_string(&"cookie monster".to_string());
1.28.0 · source

pub fn downcast_ref<T>(&self) -> Option<&T>
where T: Any,

Forwards to the method defined on the type Any.

§Examples
use std::any::Any;

fn print_if_string(s: &(dyn Any + Send + Sync)) {
    if let Some(string) = s.downcast_ref::<String>() {
        println!("It's a string({}): '{}'", string.len(), string);
    } else {
        println!("Not a string...");
    }
}

print_if_string(&0);
print_if_string(&"cookie monster".to_string());
1.28.0 · source

pub fn downcast_mut<T>(&mut self) -> Option<&mut T>
where T: Any,

Forwards to the method defined on the type Any.

§Examples
use std::any::Any;

fn modify_if_u32(s: &mut (dyn Any + Send + Sync)) {
    if let Some(num) = s.downcast_mut::<u32>() {
        *num = 42;
    }
}

let mut x = 10u32;
let mut s = "starlord".to_string();

modify_if_u32(&mut x);
modify_if_u32(&mut s);

assert_eq!(x, 42);
assert_eq!(&s, "starlord");
source

pub unsafe fn downcast_ref_unchecked<T>(&self) -> &T
where T: Any,

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

Forwards to the method defined on the type Any.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_ref_unchecked::<usize>(), 1);
}
source

pub unsafe fn downcast_mut_unchecked<T>(&mut self) -> &mut T
where T: Any,

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

Forwards to the method defined on the type Any.

§Examples
#![feature(downcast_unchecked)]

use std::any::Any;

let mut x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    *x.downcast_mut_unchecked::<usize>() += 1;
}

assert_eq!(*x.downcast_ref::<usize>().unwrap(), 2);

Trait Implementations§

1.0.0 · source§

impl Debug for dyn Any

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

impl Debug for dyn Any + Send

source§

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

Formats the value using the given formatter. Read more
1.28.0 · source§

impl Debug for dyn Any + Sync + Send

source§

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

Formats the value using the given formatter. Read more

Implementors§

1.0.0 · source§

impl<T> Any for T
where T: 'static + ?Sized,