Struct tracing_core::field::FieldSet

pub struct FieldSet { /* private fields */ }

Describes the fields present on a span.

Equality

In well-behaved applications, two FieldSets initialized with equal callsite identifiers will have identical fields. Consequently, in release builds, FieldSet::eq only checks that its arguments have equal callsites. However, the equality of field names is checked in debug builds.

Implementations

impl FieldSet

pub const fn new(names: &'static [&'static str], callsite: Identifier) -> Self

Constructs a new FieldSet with the given array of field names and callsite.

pub fn field<Q>(&self, name: &Q) -> Option<Field>

where Q: Borrow<str> + ?Sized,

Returns the Field named name, or None if no such field exists.

pub fn contains(&self, field: &Field) -> bool

Returns true if self contains the given field.

Note: If field shares a name with a field
in this FieldSet, but was created by a FieldSet
with a different callsite, this FieldSet does not
contain it. This is so that if two separate span callsites define a field
named "foo", the Field corresponding to "foo" for each
of those callsites are not equivalent.

pub fn iter(&self) -> Iter

Returns an iterator over the Fields in this FieldSet.

pub fn len(&self) -> usize

Returns the number of fields in this FieldSet.

pub fn is_empty(&self) -> bool

Returns whether or not this FieldSet has fields.

Trait Implementations

impl Debug for FieldSet

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

Formats the value using the given formatter.

impl Display for FieldSet

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

Formats the value using the given formatter.

impl<'a> IntoIterator for &'a FieldSet

type IntoIter = Iter

Which kind of iterator are we turning this into?

type Item = Field

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl PartialEq for FieldSet

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

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: 32 bytes