std::any::TypeId - Rust
Description: API documentation for the Rust `TypeId` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, TypeId

# Struct std::any::TypeId 1.0.0[−][src]

    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`

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####

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

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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);
    }Run

## Trait Implementations

###

`impl Hash for TypeId`

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####

`fn hash<__H>(&self, state: &mut __H) where __H: Hasher,`

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Feeds this value into the given [`Hasher`]. Read more

####

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

1.3.0
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Feeds a slice of this type into the given [`Hasher`]. Read more

###

`impl Clone for TypeId`

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####

`fn clone(&self) -> TypeId`

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Returns a copy of the value. Read more

####

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

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Performs copy-assignment from `source`. Read more

###

`impl Debug for TypeId`

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####

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

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Formats the value using the given formatter. Read more

###

`impl PartialOrd<TypeId> for TypeId`

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####

`fn partial_cmp(&self, other: &TypeId) -> Option<Ordering>`

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

####

`fn lt(&self, other: &TypeId) -> bool`

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

####

`fn le(&self, other: &TypeId) -> bool`

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

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`fn gt(&self, other: &TypeId) -> bool`

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

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`fn ge(&self, other: &TypeId) -> bool`

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

###

`impl Ord for TypeId`

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####

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

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This method returns an `Ordering` between `self` and `other`. Read more

####

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

1.21.0
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Compares and returns the maximum of two values. Read more

####

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

1.21.0
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Compares and returns the minimum of two values. Read more

###

`impl Eq for TypeId`

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`impl PartialEq<TypeId> for TypeId`

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####

`fn eq(&self, other: &TypeId) -> bool`

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

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`fn ne(&self, other: &TypeId) -> bool`

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This method tests for `!=`.

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`impl Copy for TypeId`

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## Auto Trait Implementations

###

`impl Send for TypeId`

###

`impl Sync for TypeId`

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