Struct tracing_subscriber::fmt::FormattedFields

pub struct FormattedFields<E> {
    pub fields: String,
    // some fields omitted
}

A formatted representation of a span’s fields stored in its extensions.

Because FormattedFields is generic over the type of the formatter that produced it, multiple versions of a span’s formatted fields can be stored in the Extensions type-map. This means that when multiple formatters are in use, each can store its own formatted representation without conflicting.

Fields

fields: String

The formatted fields of a span.

Implementations

impl<E> FormattedFields<E>

pub fn new(fields: String) -> Self

Returns a new FormattedFields.

Methods from Deref<Target = String>

pub fn as_str(&self) -> &str

Extracts a string slice containing the entire String.

Examples

Basic usage:

let s = String::from("foo");

assert_eq!("foo", s.as_str());

pub fn capacity(&self) -> usize

Returns this String’s capacity, in bytes.

Examples

Basic usage:

let s = String::with_capacity(10);

assert!(s.capacity() >= 10);

pub fn as_bytes(&self) -> &[u8]

Returns a byte slice of this String’s contents.

The inverse of this method is from_utf8.

Examples

Basic usage:

let s = String::from("hello");

assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes());

pub fn len(&self) -> usize

Returns the length of this String, in bytes, not chars or graphemes. In other words, it may not be what a human considers the length of the string.

Examples

Basic usage:

let a = String::from("foo");
assert_eq!(a.len(), 3);

let fancy_f = String::from("ƒoo");
assert_eq!(fancy_f.len(), 4);
assert_eq!(fancy_f.chars().count(), 3);

pub fn is_empty(&self) -> bool

Returns true if this String has a length of zero, and false otherwise.

Examples

Basic usage:

let mut v = String::new();
assert!(v.is_empty());

v.push('a');
assert!(!v.is_empty());

Trait Implementations

impl<E> Debug for FormattedFields<E>

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

Formats the value using the given formatter.

impl<E: Default> Default for FormattedFields<E>

fn default() -> FormattedFields<E>

Returns the “default value” for a type.

impl<E> Deref for FormattedFields<E>

type Target = String

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<E> Display for FormattedFields<E>

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

Formats the value using the given formatter.