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

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<'a> AsField for &'a Field

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

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

impl AsField for Field

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

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

impl AsRef<str> for Field

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

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 Debug for Field

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

Formats the value using the given formatter.

impl Display 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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Field

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Field

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: 40 bytes