Struct std::any::TypeId

pub struct TypeId { /* fields omitted */ }

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 fn of<T>() -> TypeId where
    T: 'static + ?Sized, 

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 Eq for TypeId

impl Debug for TypeId

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

Formats the value using the given formatter.

impl PartialEq<TypeId> for TypeId

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 PartialOrd<TypeId> for TypeId

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 Hash for TypeId

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 Ord for TypeId

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

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

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

Restrict a value to a certain interval.

impl Clone for TypeId

fn clone(&self) -> TypeId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for TypeId