Struct tracing::field::Field

pub struct Field { /* fields omitted */ }

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.

Methods

impl Field

pub fn callsite(&self) -> Identifier

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

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

Returns a string representing the name of the field.

Trait Implementations

impl Eq for Field

impl Display for Field

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

Formats the value using the given formatter.

impl Clone for Field

fn clone(&self) -> Field

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl AsRef<str> for Field

fn as_ref(&self) -> &str

Performs the conversion.

impl PartialEq<Field> for Field

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Debug for Field

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

Formats the value using the given formatter.

impl Hash for Field

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

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl AsField for Field

fn as_field(&self, metadata: &Metadata) -> Option<Field>

Attempts to convert &self into a Field with the specified metadata.

impl<'a> AsField for &'a Field

fn as_field(&self, metadata: &Metadata) -> Option<Field>

Attempts to convert &self into a Field with the specified metadata.