pub struct TypeId { /* private fields */ }
Available on crate feature
std
only.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§
Source§impl TypeId
impl TypeId
1.0.0 (const: unstable) · Sourcepub fn of<T>() -> TypeIdwhere
T: 'static + ?Sized,
pub fn of<T>() -> TypeIdwhere
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);
Trait Implementations§
1.0.0 · Source§impl Ord for TypeId
impl Ord for TypeId
1.0.0 · Source§impl PartialOrd for TypeId
impl PartialOrd for TypeId
impl Copy for TypeId
impl Eq for TypeId
Auto Trait Implementations§
impl Freeze for TypeId
impl RefUnwindSafe for TypeId
impl Send for TypeId
impl Sync for TypeId
impl Unpin for TypeId
impl UnwindSafe for TypeId
Blanket Implementations§
Source§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
Source§type ArchivedMetadata = ()
type ArchivedMetadata = ()
The archived version of the pointer metadata for this type.
Source§fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata,
) -> <T as Pointee>::Metadata
fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata, ) -> <T as Pointee>::Metadata
Converts some archived metadata to the pointer metadata for itself.
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to
key
and return true
if they are equal.Source§impl<T> LayoutRaw for T
impl<T> LayoutRaw for T
Source§fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
Returns the layout of the type.
Source§impl<T, N1, N2> Niching<NichedOption<T, N1>> for N2
impl<T, N1, N2> Niching<NichedOption<T, N1>> for N2
Source§unsafe fn is_niched(niched: *const NichedOption<T, N1>) -> bool
unsafe fn is_niched(niched: *const NichedOption<T, N1>) -> bool
Returns whether the given value has been niched. Read more
Source§fn resolve_niched(out: Place<NichedOption<T, N1>>)
fn resolve_niched(out: Place<NichedOption<T, N1>>)
Writes data to
out
indicating that a T
is niched.