Struct core::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 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

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

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.

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 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 Hash for TypeId

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

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

Formats the value using the given formatter.