# Enum rustc_borrowck::universal_regions::RegionClassification

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    pub enum RegionClassification {
        Global,
        External,
        Local,
    }

## Variants§

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### Global

A global region is one that can be named from anywhere. There is only one, `'static`.

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### External

An external region is only relevant for closures, coroutines, and inline consts. In that case, it refers to regions that are free in the type – basically, something bound in the surrounding context.

Consider this example:

ⓘ

    fn foo<'a, 'b>(a: &'a u32, b: &'b u32, c: &'static u32) {
      let closure = for<'x> |x: &'x u32| { .. };
       //           ^^^^^^^ pretend this were legal syntax
       //                   for declaring a late-bound region in
       //                   a closure signature
    }

Here, the lifetimes `'a` and `'b` would be external to the closure.

If we are not analyzing a closure/coroutine/inline-const, there are no external lifetimes.

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### Local

A local lifetime is one about which we know the full set of relevant constraints (that is, relationships to other named regions). For a closure, this includes any region bound in the closure’s signature. For a fn item, this includes all regions other than global ones.

Continuing with the example from `External`, if we were analyzing the closure, then `'x` would be local (and `'a` and `'b` are external). If we are analyzing the function item `foo`, then `'a` and `'b` are local (and `'x` is not in scope).

## Trait Implementations§

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### impl Debug for RegionClassification

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

Formats the value using the given formatter. Read more
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### impl PartialEq for RegionClassification

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#### fn eq(&self, other: &RegionClassification) -> 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 StructuralPartialEq for RegionClassification

## Auto Trait Implementations§

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### impl RefUnwindSafe for RegionClassification

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### impl Send for RegionClassification

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### impl Sync for RegionClassification

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### impl Unpin for RegionClassification

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### impl UnwindSafe for RegionClassification

## Blanket Implementations§

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### impl<T> Any for T
where 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 T
where 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 T
where 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 T
where 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, U> TryFrom<U> for T
where 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 T
where 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.

## Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain `repr(...)` attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 1 byte

Size for each variant:

- `Global`: 0 bytes
- `External`: 0 bytes
- `Local`: 0 bytes