Structured data associated with
Value which serializes as a string using
Value which serializes using
An empty field.
An opaque key allowing O(1) access to a field in a
Describes the fields present on a span.
An iterator over a set of fields.
A set of fields and values for a span.
Trait implemented to allow a type to be used as a field key.
A field value of an erased type.
Visits typed values.