Struct core::any::TypeId

[+] Show declaration

pub struct TypeId { /* fields omitted */ }

[−] Expand description

A TypeId represents a globally unique identifier for a type.

Each TypeId is an opaque object which does not allow inspection of what's inside but does allow basic operations such as cloning, comparison, printing, and showing.

A TypeId is currently only available for types which ascribe to 'static, but this limitation may be removed in the future.

While TypeId implements Hash, PartialOrd, and Ord, it is worth noting that the hashes and ordering will vary between Rust releases. Beware of relying on them inside of your code!

Methods

impl TypeId[−]

pub const fn of<T: ?Sized + 'static>() -> TypeId[−]

Returns the TypeId of the type this generic function has been instantiated with.

Examples

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

fn is_string<T: ?Sized + Any>(_s: &T) -> bool {
    TypeId::of::<String>() == TypeId::of::<T>()
}

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

Trait Implementations

impl Copy for TypeId

impl PartialEq<TypeId> for TypeId[+]

[+] Show hidden undocumented items

fn eq(&self, other: &TypeId) -> bool[−]

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

fn ne(&self, other: &TypeId) -> bool[−]

This method tests for !=.

impl Eq for TypeId

impl Ord for TypeId[+]

[+] Show hidden undocumented items

fn cmp(&self, other: &TypeId) -> 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, [−]

🔬 This is a nightly-only experimental API. (clamp #44095)

Restrict a value to a certain interval.

impl PartialOrd<TypeId> for TypeId[+]

[+] Show hidden undocumented items

fn partial_cmp(&self, other: &TypeId) -> Option<Ordering>[−]

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

fn lt(&self, other: &TypeId) -> bool[−]

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

fn le(&self, other: &TypeId) -> bool[−]

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

fn gt(&self, other: &TypeId) -> bool[−]

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

fn ge(&self, other: &TypeId) -> bool[−]

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

impl Clone for TypeId[+]

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fn clone(&self) -> TypeId[−]

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl Hash for TypeId[+]

[+] Show hidden undocumented items

fn hash<__H: Hasher>(&self, state: &mut __H)[−]

Feeds this value into the given [Hasher].

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

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

impl Debug for TypeId[+]

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

Formats the value using the given formatter.