# Struct std::any::TypeId

1.0.0 · source ·

    pub struct TypeId { /* private fields */ }

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!

## Implementations§

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### impl TypeId

const: unstable · source

#### 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>()
    }

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

Run

## Trait Implementations§

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### impl Clone for TypeId

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#### fn clone(&self) -> TypeId

Returns a copy of the value. Read more
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#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more
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### impl Debug for TypeId

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

Formats the value using the given formatter. Read more
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### impl Hash for TypeId

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#### fn hash<H>(&self, state: &mut H)where H: Hasher,

Feeds this value into the given `Hasher`. Read more
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#### fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given `Hasher`. Read more
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### impl Ord for TypeId

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

This method returns an `Ordering` between `self` and `other`. Read more
1.21.0 · source§

#### fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values. Read more
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#### fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values. Read more
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#### fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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### impl PartialEq for TypeId

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

This method tests for `self` and `other` values to be equal, and is used by `==`.
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#### fn ne(&self, other: &Rhs) -> bool

This method tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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### impl PartialOrd for TypeId

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

This method returns an ordering between `self` and `other` values if one exists. Read more
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#### fn lt(&self, other: &Rhs) -> bool

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more
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#### fn le(&self, other: &Rhs) -> bool

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: &Rhs) -> bool

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: &Rhs) -> bool

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

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### impl Eq for TypeId

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### impl StructuralEq for TypeId

## Auto Trait Implementations§

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### impl RefUnwindSafe for TypeId

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### impl Send for TypeId

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### impl Sync for TypeId

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### impl Unpin for TypeId

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### impl UnwindSafe for TypeId

## Blanket Implementations§

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

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for Twhere T: ?Sized,

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#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for Twhere T: ?Sized,

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#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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### impl<T> From<T> for T

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#### fn from(t: T) -> T

Returns the argument unchanged.

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### impl<T, U> Into<U> for Twhere U: From<T>,

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#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<T> ToOwned for Twhere T: Clone,

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#### type Owned = T

The resulting type after obtaining ownership.
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#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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### impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.