Struct Field

pub struct Field { /* private fields */ }

An opaque key allowing O(1) access to a field in a Span's key-value data.

As keys are defined by the metadata of a span, rather than by an individual instance of a span, a key may be used to access the same field across all instances of a given span with the same metadata. Thus, when a subscriber observes a new span, it need only access a field by name once, and use the key for that name for all other accesses.

Implementations

impl Field

fn callsite(&self) -> Identifier

Returns an Identifier that uniquely identifies the Callsite which defines this field.

fn name(&self) -> &'static str

Returns a string representing the name of the field.

fn index(&self) -> usize

Returns the index of this field in its FieldSet.

Trait Implementations

impl AsRef<str> for Field

fn as_ref(&self) -> &str

impl Clone for Field

fn clone(&self) -> Self

impl Debug for Field

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

impl Display for Field

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

impl Eq for Field

impl Hash for Field

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

impl PartialEq for Field

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

Auto Trait Implementations

impl !RefUnwindSafe for Field

impl !UnwindSafe for Field

impl Freeze for Field

impl Send for Field

impl Sync for Field

impl Unpin for Field

impl UnsafeUnpin for Field

Blanket Implementations

impl<T> Any for Field where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Field where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Field where T: ?Sized,

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

impl<T> CloneToUninit for Field where T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

impl<T> From<T> for Field

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> ToOwned for Field where T: Clone,

type Owned = T;
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)

impl<T> ToString for Field where T: Display + ?Sized,

fn to_string(&self) -> String

impl<T, U> Into<U> for Field where U: From<T>,

fn into(self) -> U

Calls U::from(self).

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

impl<T, U> TryFrom<U> for Field where U: Into<T>,

type Error = never;
fn try_from(value: U) -> Result<T, never>

impl<T, U> TryInto<U> for Field where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>