pub enum RegionClassification {
Global,
External,
Local,
}
Variants
Global
A global region is one that can be named from
anywhere. There is only one, 'static
.
External
An external region is only relevant for closures, generators, 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/generator/inline-const, there are no external lifetimes.
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
sourceimpl Debug for RegionClassification
impl Debug for RegionClassification
sourceimpl PartialEq<RegionClassification> for RegionClassification
impl PartialEq<RegionClassification> for RegionClassification
sourcefn eq(&self, other: &RegionClassification) -> bool
fn eq(&self, other: &RegionClassification) -> bool
impl StructuralPartialEq for RegionClassification
Auto Trait Implementations
impl RefUnwindSafe for RegionClassification
impl Send for RegionClassification
impl Sync for RegionClassification
impl Unpin for RegionClassification
impl UnwindSafe for RegionClassification
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
impl<'a, T> Captures<'a> for Twhere
T: ?Sized,
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 bytesExternal
: 0 bytesLocal
: 0 bytes