rama::utils::collections::smallvec::alloc::fmt

Trait Debug

1.36.0 · Source

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

Expand description

? 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 (std, core, alloc, 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.

Types that do not wish to use the standard suite of debug representations provided by the Formatter trait (debug_struct, debug_tuple, debug_list, debug_set, debug_map) can do something totally custom by manually writing an arbitrary representation to the Formatter.

impl fmt::Debug for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Point [{} {}]", self.x, self.y)
    }
}

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 };

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

Required Methods§

1.0.0 · Source

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

Formats the value using the given formatter.

§Errors

This function should return Err if, and only if, the provided Formatter returns Err. String formatting is considered an infallible operation; this function only returns a Result because writing to the underlying stream might fail and it must provide a way to propagate the fact that an error has occurred back up the stack.

§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,
)");

Dyn Compatibility§

This trait is dyn compatible.

Available on target_has_atomic_load_store=8 only.

Shows the underlying bytes as a normal string, with invalid UTF-8 presented as hex escape sequences.

1.0.0 · Source§

impl Debug for CString

Delegates to the CStr implementation of fmt::Debug, showing invalid UTF-8 as hex escapes.

impl Debug for CertOrderInput

Available on crate features dns and http-backend and http and std and tcp and tls only.

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impl Debug for CertOrderOutput

Available on crate features dns and http-backend and http and std and tcp and tls only.

Converts a DateTime into a human readable datetime string.

(This Debug representation currently emits the same string as the Display representation, but this is not a guarantee.)

Options currently supported:

std::fmt::Formatter::precision can be set to control the precision of the fractional second component.

§Example

use jiff::civil::date;

let dt = date(2024, 6, 15).at(7, 0, 0, 123_000_000);
assert_eq!(format!("{dt:.6?}"), "2024-06-15T07:00:00.123000");
// Precision values greater than 9 are clamped to 9.
assert_eq!(format!("{dt:.300?}"), "2024-06-15T07:00:00.123000000");
// A precision of 0 implies the entire fractional
// component is always truncated.
assert_eq!(format!("{dt:.0?}"), "2024-06-15T07:00:00");

Available on crate features dns and http-backend and http and std and tcp only.

impl Debug for Evaporation

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impl Debug for Event

When the alternate flag is enabled this will print platform specific details, for example the fields of the kevent structure on platforms that use kqueue(2). Note however that the output of this implementation is not consider a part of the stable API.

impl Debug for Http

Available on crate features cli and haproxy and http and net and std only.

The value is intentionally omitted from the output to avoid leaking secrets.

Available on Apple only.

Source §

impl Debug for OsLogLayer

Available on Apple only.

Source §

impl Debug for OsLogType

Available on Apple only.

Available on crate features dns and http-backend and http and std and tcp only.

Avoids writing the value or position to avoid creating a side channel, though Reader can’t avoid leaking the position via timing.

Available on neither Horizon nor Redox OS nor WASI.

Available on crate feature all and (Android or Linux) only.

impl Debug for proc_macro::Span

Prints a span in a form convenient for debugging.

Available on Apple only.

use nu_ansi_term::Color::{Red, Blue};
assert_eq!("Style { fg(Red), on(Blue), bold, italic }",
           format!("{:?}", Red.on(Blue).bold().italic()));

Debug implementation does not leak internal state

§

impl Debug for ThreadRng

Debug implementation does not leak internal state

impl Debug for TicketSwitcher

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impl Debug for Time

Converts a Time into a human readable time string.

(This Debug representation currently emits the same string as the Display representation, but this is not a guarantee.)

Options currently supported:

std::fmt::Formatter::precision can be set to control the precision of the fractional second component.

§Example

use jiff::civil::time;

let t = time(7, 0, 0, 123_000_000);
assert_eq!(format!("{t:.6?}"), "07:00:00.123000");
// Precision values greater than 9 are clamped to 9.
assert_eq!(format!("{t:.300?}"), "07:00:00.123000000");
// A precision of 0 implies the entire fractional
// component is always truncated.
assert_eq!(format!("{t:.0?}"), "07:00:00");

§

impl Debug for Timestamp

§

impl Debug for Timestamp

Converts a Timestamp datetime into a human readable datetime string.

(This Debug representation currently emits the same string as the Display representation, but this is not a guarantee.)

Options currently supported:

std::fmt::Formatter::precision can be set to control the precision of the fractional second component.

§Example

use jiff::Timestamp;

let ts = Timestamp::new(1_123_456_789, 123_000_000)?;
assert_eq!(
    format!("{ts:.6?}"),
    "2005-08-07T23:19:49.123000Z",
);
// Precision values greater than 9 are clamped to 9.
assert_eq!(
    format!("{ts:.300?}"),
    "2005-08-07T23:19:49.123000000Z",
);
// A precision of 0 implies the entire fractional
// component is always truncated.
assert_eq!(
    format!("{ts:.0?}"),
    "2005-08-07T23:19:49Z",
);

Prints token in a form convenient for debugging.

1.15.0 · Source§

impl Debug for proc_macro::TokenStream

Prints tokens in a form convenient for debugging.

Source §

impl Debug for proc_macro2::TokenTree

Prints token tree in a form convenient for debugging.

1.29.0 · Source§

impl Debug for proc_macro::TokenTree

Prints token tree in a form convenient for debugging.

Available on crate features cli and haproxy and http and net and std only.

§

impl Debug for TransportProtocol

Source §

impl Debug for TransportStage

Available on crate features dns and http-backend and http and std and tcp only.

Debug the serialization of this URL.

Available on neither Horizon nor OpenBSD nor Redox OS nor WASI.

Options currently supported:

std::fmt::Formatter::precision can be set to control the precision of the fractional second component.

§Example

use jiff::civil::date;

let zdt = date(2024, 6, 15).at(7, 0, 0, 123_000_000).in_tz("US/Eastern")?;
assert_eq!(
    format!("{zdt:.6?}"),
    "2024-06-15T07:00:00.123000-04:00[US/Eastern]",
);
// Precision values greater than 9 are clamped to 9.
assert_eq!(
    format!("{zdt:.300?}"),
    "2024-06-15T07:00:00.123000000-04:00[US/Eastern]",
);
// A precision of 0 implies the entire fractional
// component is always truncated.
assert_eq!(
    format!("{zdt:.0?}"),
    "2024-06-15T07:00:00-04:00[US/Eastern]",
);

impl<'a, R> Debug for ScopeFromRoot<'a, R>
where R: LookupSpan<'a>,

Available on crate features alloc or std only.

impl<'name, 'bufs, 'control> Debug for MsgHdr<'name, 'bufs, 'control>

Available on neither Horizon nor Redox OS nor WASI.

§

impl<'name, 'bufs, 'control> Debug for MsgHdrMut<'name, 'bufs, 'control>

Available on neither Horizon nor Redox OS nor WASI.

impl<H: Debug> Debug for FsServiceBuilder<H>

Available on crate features cli and haproxy and http and net and std only.

impl<R> Debug for RngReadAdapter<'_, R>
where R: TryRngCore + ?Sized,

Available on crate feature std only.

§

impl<R> Debug for RngReader<R>
where R: TryRng,

Available on crate feature std only.

Available on crate features dns and http-backend and http and std and tcp only.

Source §

impl<S: Debug> Debug for ProxyConnector<S>

Available on crate features dns and http-backend and http and std and tcp only.

This trait is implemented for tuples up to twelve items long.

impl<T> Debug for rama::telemetry::opentelemetry::metrics::Counter<T>
where T: Debug,

Source §

impl<T> Debug for CovariantUnsafeCell<T>
where T: ?Sized,

§

impl<T> Debug for CreationError<T>
where T: Debug,

Available on crate feature alloc only.

Source §

impl<const PROXY: bool> Debug for ProxyStage<PROXY>

Available on crate features dns and http-backend and http and std and tcp only.

Source §

impl<const PROXY: bool> Debug for TlsStage<PROXY>

Available on crate features dns and http-backend and http and std and tcp only.

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impl<const SEPARATOR: char> Debug for Composer<SEPARATOR>

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impl<const SIZE: usize> Debug for WriteBuffer<SIZE>

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impl<const TLS_PROXY: bool> Debug for ProxyTunnelStage<TLS_PROXY>

Available on crate features dns and http-backend and http and std and tcp only.

Debug

Trait Debug Copy item path

§Stability

§Examples

Required Methods§

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

§Errors

§Examples

Dyn Compatibility§

Implementors§

impl Debug for !

impl Debug for &dyn TargetIsa

impl Debug for &dyn TargetIsa

impl Debug for ()

impl Debug for A

impl Debug for AAAA

impl Debug for AArch64

impl Debug for ACCESS_DESCRIPTION_st

impl Debug for AHasher

impl Debug for ANAME

impl Debug for ASN1DateTime

impl Debug for ASN1Error

impl Debug for ASN1ErrorKind

impl Debug for ASN1Time

impl Debug for ASN1TimeZone

impl Debug for ASN1_ADB_TABLE_st

impl Debug for ASN1_ADB_st

impl Debug for ASN1_AUX_st

impl Debug for ASN1_ITEM_st

impl Debug for ASN1_ITEM_st

impl Debug for ASN1_TEMPLATE_st

impl Debug for ASN1_TEMPLATE_st

impl Debug for ASN1_TLC_st

impl Debug for ASN1_VALUE_st

impl Debug for ASN1_VALUE_st

impl Debug for ATerm

impl Debug for AUTHORITY_KEYID_st

impl Debug for AUTHORITY_KEYID_st

impl Debug for Aarch64Architecture

impl Debug for Abbreviation

impl Debug for Abbreviations

impl Debug for AbbreviationsCache

impl Debug for AbbreviationsCacheStrategy

impl Debug for rama::crypto::dep::x509_parser::prelude::asn1_rs::nom::lib::std::mem::type_info::Abi

impl Debug for Abi

impl Debug for AbiParam

impl Debug for AbortController

impl Debug for AbortHandle

impl Debug for rama::futures::prelude::future::AbortHandle

impl Debug for AbortRegistration

impl Debug for rama::layer::abort::Aborted

impl Debug for rama::futures::prelude::future::Aborted

impl Debug for AbstractHeapType

impl Debug for AbstractHeapType

impl Debug for AbstractResourceIndex

impl Debug for Accept

impl Debug for AcceptCh

impl Debug for AcceptEncoding

impl Debug for AcceptRanges

impl Debug for Accepted

impl Debug for AcceptedAlert

impl Debug for AcceptedWebSocketData

impl Debug for AcceptedWebSocketProtocol

impl Debug for Access

impl Debug for AccessControlAllowCredentials

impl Debug for AccessControlAllowHeaders

impl Debug for AccessControlAllowMethods

impl Debug for AccessControlAllowOrigin

impl Debug for AccessControlAllowPrivateNetwork

impl Debug for AccessControlExposeHeaders

impl Debug for AccessControlMaxAge

impl Debug for AccessControlRequestHeaders

impl Debug for AccessControlRequestMethod

impl Debug for AccessControlRequestPrivateNetwork

impl Debug for AccessControlSet

impl Debug for AccessError

impl Debug for Account

impl Debug for AccountStatus

impl Debug for AcmeClient

impl Debug for AcmeProvider

Trait Debug