pub struct FieldSet { /* private fields */ }
Expand description

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§

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

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

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.

Returns an iterator over the Fields in this FieldSet.

Returns the number of fields in this FieldSet.

Returns whether or not this FieldSet has fields.

Trait Implementations§

Formats the value using the given formatter. Read more
Formats the value using the given formatter. Read more
Which kind of iterator are we turning this into?
The type of the elements being iterated over.
Creates an iterator from a value. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
TODO: once 1.33.0 is the minimum supported compiler version, remove Any::type_id_compat and use StdAny::type_id instead. https://github.com/rust-lang/rust/issues/27745
The archived version of the pointer metadata for this type.
Converts some archived metadata to the pointer metadata for itself.
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Deserializes using the given deserializer
Compare self to key and return true if they are equal.

Returns the argument unchanged.

Attaches the provided Context to this type, returning a WithContext wrapper. Read more
Attaches the current Context to this type, returning a WithContext wrapper. Read more
Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more
Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

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

The alignment of pointer.
The type for initializers.
Initializes a with the given initializer. Read more
Dereferences the given pointer. Read more
Mutably dereferences the given pointer. Read more
Drops the object pointed to by the given pointer. Read more
The type for metadata in pointers and references to Self.
Should always be Self
The inverse inclusion map: attempts to construct self from the equivalent element of its superset. Read more
Checks if self is actually part of its subset T (and can be converted to it).
Use with care! Same as self.to_subset but without any property checks. Always succeeds.
The inclusion map: converts self to the equivalent element of its superset.
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
upcast ref
upcast mut ref
upcast boxed dyn
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more