Struct tracing::stdlib::fmt::FormatterFn

pub struct FormatterFn<F>(pub F)
where
    F: Fn(&mut Formatter<'_>) -> Result<(), Error>;

🔬This is a nightly-only experimental API. (debug_closure_helpers #117729)

Implements fmt::Debug and fmt::Display using a function.

Examples

#![feature(debug_closure_helpers)]
use std::fmt;

let value = 'a';
assert_eq!(format!("{}", value), "a");
assert_eq!(format!("{:?}", value), "'a'");

let wrapped = fmt::FormatterFn(|f| write!(f, "{:?}", &value));
assert_eq!(format!("{}", wrapped), "'a'");
assert_eq!(format!("{:?}", wrapped), "'a'");

Tuple Fields

0: F

🔬This is a nightly-only experimental API. (debug_closure_helpers #117729)

Trait Implementations

impl<F> Debug for FormatterFn<F>

where F: Fn(&mut Formatter<'_>) -> Result<(), Error>,

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

Formats the value using the given formatter.

impl<F> Display for FormatterFn<F>

where F: Fn(&mut Formatter<'_>) -> Result<(), Error>,

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

Formats the value using the given formatter.