Struct tracing_core::span::Current

pub struct Current { /* private fields */ }

Indicates what the Subscriber considers the “current” span.

As subscribers may not track a notion of a current span, this has three possible states:

• “unknown”, indicating that the subscriber does not track a current span,
• “none”, indicating that the current context is known to not be in a span,
• “some”, with the current span’s Id and Metadata.

Implementations

impl Current

pub fn new(id: Id, metadata: &'static Metadata<'static>) -> Self

Constructs a new Current that indicates the current context is a span with the given metadata and metadata.

pub fn none() -> Self

Constructs a new Current that indicates the current context is not in a span.

pub fn is_known(&self) -> bool

Returns true if the Subscriber that constructed this Current tracks a current span.

If this returns true and id, metadata, or into_inner return None, that indicates that we are currently known to not be inside a span. If this returns false, those methods will also return None, but in this case, that is because the subscriber does not keep track of the currently-entered span.

pub fn into_inner(self) -> Option<(Id, &'static Metadata<'static>)>

Consumes self and returns the span Id and Metadata of the current span, if one exists and is known.

pub fn id(&self) -> Option<&Id>

Borrows the Id of the current span, if one exists and is known.

pub fn metadata(&self) -> Option<&'static Metadata<'static>>

Borrows the Metadata of the current span, if one exists and is known.

Trait Implementations

impl Debug for Current

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

Formats the value using the given formatter.

impl<'a> From<&'a Current> for Option<&'a Id>

fn from(cur: &'a Current) -> Self

Performs the conversion.

impl<'a> From<&'a Current> for Option<Id>

fn from(cur: &'a Current) -> Self

Performs the conversion.

impl<'a> From<&'a Current> for Option<&'static Metadata<'static>>

fn from(cur: &'a Current) -> Self

Performs the conversion.

impl From<Current> for Option<Id>

fn from(cur: Current) -> Self

Performs the conversion.