Trait nom::lib::std::fmt::Debug1.0.0[−][src]

[+] Show declaration

pub trait Debug {
    pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}

[−]

? formatting.

Debug should format the output in a programmer-facing, debugging context.

Generally speaking, you should just derive a Debug implementation.

When used with the alternate format specifier #?, the output is pretty-printed.

For more information on formatters, see the module-level documentation.

This trait can be used with #[derive] if all fields implement Debug. When derived for structs, it will use the name of the struct, then {, then a comma-separated list of each field’s name and Debug value, then }. For enums, it will use the name of the variant and, if applicable, (, then the Debug values of the fields, then ).

Stability

Derived Debug formats are not stable, and so may change with future Rust versions. Additionally, Debug implementations of types provided by the standard library (libstd, libcore, liballoc, etc.) are not stable, and may also change with future Rust versions.

Examples

Deriving an implementation:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {:?}", origin), "The origin is: Point { x: 0, y: 0 }");

Manually implementing:

use std::fmt;

struct Point {
    x: i32,
    y: i32,
}

impl fmt::Debug for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Point")
         .field("x", &self.x)
         .field("y", &self.y)
         .finish()
    }
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {:?}", origin), "The origin is: Point { x: 0, y: 0 }");

There are a number of helper methods on the Formatter struct to help you with manual implementations, such as debug_struct.

Debug implementations using either derive or the debug builder API on Formatter support pretty-printing using the alternate flag: {:#?}.

Pretty-printing with #?:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {:#?}", origin),
"The origin is: Point {
    x: 0,
    y: 0,
}");

Required methods

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src][−]

Formats the value using the given formatter.

Examples

use std::fmt;

struct Position {
    longitude: f32,
    latitude: f32,
}

impl fmt::Debug for Position {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("")
         .field(&self.longitude)
         .field(&self.latitude)
         .finish()
    }
}

let position = Position { longitude: 1.987, latitude: 2.983 };
assert_eq!(format!("{:?}", position), "(1.987, 2.983)");

assert_eq!(format!("{:#?}", position), "(
    1.987,
    2.983,
)");

Trait nom::lib::std::fmt::Debug⎘1.0.0[−][src]

Stability

Examples

Required methods

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>[src][−]

Examples

Implementations on Foreign Types

impl Debug for UdpSocket[src][−]

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

impl Debug for Error[src][−]

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

impl Debug for SocketAddrV6[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl<T> Debug for IntoIter<T> where T: Debug, [src][−]

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

impl Debug for BacktraceFrame[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for SystemTime[src][−]

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

impl<W> Debug for IntoInnerError<W> where W: Debug, [src][−]

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

impl Debug for Args[src][−]

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

impl<R> Debug for BufReader<R> where R: Debug, [src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for RecvError[src][−]

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

impl Debug for AncillaryError[src][−]

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

impl<T> Debug for SyncSender<T>[src][−]

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

impl Debug for UnixDatagram[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for Vars[src][−]

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

impl Debug for PathBuf[src][−]

pub fn fmt(&self, formatter: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for TcpStream[src][−]

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

impl<'a> Debug for IoSliceMut<'a>[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl<T> Debug for PoisonError<T>[src][−]

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

impl Debug for Child[src][−]

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

impl Debug for TcpListener[src][−]

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

impl Debug for ExitCode[src][−]

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

impl Debug for FromBytesWithNulError[src][−]

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

impl<'_, T> Debug for MutexGuard<'_, T> where T: Debug + ?Sized, [src][−]

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

impl Debug for FromVecWithNulError[src][−]

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

impl Debug for IpAddr[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl<T> Debug for Take<T> where T: Debug, [src][−]

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

impl Debug for OpenOptions[src][−]

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

impl Debug for WaitTimeoutResult[src][−]

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

impl<'a> Debug for Incoming<'a>[src][−]

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

impl Debug for OsStr[src][−]

pub fn fmt(&self, formatter: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for StripPrefixError[src][−]

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

impl<T> Debug for JoinHandle<T>[src][−]

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

impl Debug for Once[src][−]

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

impl Debug for ExitStatus[src][−]

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

impl<'a> Debug for Ancestors<'a>[src][−]

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

impl Debug for UnixStream[src][−]

pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>[src]

impl Debug for Initializer[src][−]

Trait nom::lib::std::fmt::Debug1.0.0[−][src]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src][−]

`impl Debug for UdpSocket`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Error`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for SocketAddrV6`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<T> Debug for IntoIter<T> where T: Debug,` [src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for BacktraceFrame`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for SystemTime`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<W> Debug for IntoInnerError<W> where W: Debug,` [src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Args`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<R> Debug for BufReader<R> where R: Debug,` [src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for RecvError`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for AncillaryError`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<T> Debug for SyncSender<T>`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for UnixDatagram`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Vars`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for PathBuf`[src][−]

`pub fn fmt(&self, formatter: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for TcpStream`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<'a> Debug for IoSliceMut<'a>`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<T> Debug for PoisonError<T>`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Child`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for TcpListener`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for ExitCode`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for FromBytesWithNulError`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<'_, T> Debug for MutexGuard<'_, T> where T: Debug + ?Sized,` [src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for FromVecWithNulError`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for IpAddr`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<T> Debug for Take<T> where T: Debug,` [src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for OpenOptions`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for WaitTimeoutResult`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<'a> Debug for Incoming<'a>`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for OsStr`[src][−]

`pub fn fmt(&self, formatter: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for StripPrefixError`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<T> Debug for JoinHandle<T>`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Once`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for ExitStatus`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl<'a> Debug for Ancestors<'a>`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for UnixStream`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Initializer`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for Backtrace`[src][−]

`pub fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), Error>`[src]

`impl Debug for ErrorKind`[src][−]

`pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>`[src]