cosmic::cctk::sctk::reexports::client::backend::smallvec::alloc::fmt

Trait Debug

1.36.0 · Source

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

Available on crate feature wayland and Linux only.

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,
)");

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impl Debug for cosmic::applet::row::State

Available on crate feature applet only.

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impl Debug for cosmic::applet::Context

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impl Debug for DesktopAction

Available on crate feature desktop only.

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impl Debug for DesktopEntryCache

Available on crate feature desktop only.

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impl Debug for DesktopEntryData

Available on crate feature desktop only.

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impl Debug for DesktopResolveOptions

Available on crate feature desktop only.

impl Debug for cosmic::widget::wayland::tooltip::widget::State

Available on crate feature winit only.

impl Debug for __m512h

1.72.0 · Source§

impl Debug for __m512i

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impl Debug for core::core_arch::x86::bf16

1.3.0 · Source§

impl Debug for CStr

1.15.0 · Source§

impl Debug for proc_macro::TokenStream

impl Debug for proc_macro2::Punct

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impl Debug for proc_macro2::Span

Prints a span in a form convenient for debugging.

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impl Debug for proc_macro2::TokenStream

Prints token in a form convenient for debugging.

Debug the serialization of this URL.

Debug implementation does not leak internal state

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");

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 Rasterizer

let rasterizer = ab_glyph_rasterizer::Rasterizer::new(3, 4);
assert_eq!(
    &format!("{:?}", rasterizer),
    "Rasterizer { width: 3, height: 4 }"
);

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");

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",
);

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]",
);

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impl<'p> Debug for DbusActivationInterfaceProxyBlocking<'p>

Available on crate feature single-instance only.

Available on crate feature single-instance only.

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impl<Action: Debug, Args: Debug> Debug for cosmic::dbus_activation::Message<Action, Args>

impl<T> Debug for &T
where T: Debug + ?Sized,

1.0.0 · Source§

impl<T> Debug for &mut T
where T: Debug + ?Sized,

1.0.0 · Source§

impl<T> Debug for [T]
where T: Debug,

1.0.0 · Source§

impl<T> Debug for (T₁, T₂, …, Tₙ)
where T: Debug,

Trait DebugCopy item path

§Stability

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Debug for WindowingSystem

impl Debug for cosmic::app::Action

impl Debug for PanelType

impl Debug for cosmic::applet::Size

impl Debug for cosmic::cosmic_config::Error

impl Debug for CosmicPalette

impl Debug for Density

impl Debug for cosmic::cosmic_theme::Layer

impl Debug for Equation

impl Debug for Parameter

impl Debug for VecCastErrorKind

impl Debug for cosmic::cosmic_theme::palette::rgb::FromHexError

impl Debug for cosmic::dialog::file_chooser::Error

impl Debug for cosmic::iced::advanced::subscription::Event

impl Debug for cosmic::iced::clipboard::dnd::SourceEvent

impl Debug for SurfaceError

impl Debug for cosmic::iced::daemon::program::graphics::core::alignment::Horizontal

impl Debug for cosmic::iced::daemon::program::graphics::core::alignment::Vertical

impl Debug for Easing

impl Debug for cosmic::iced::daemon::program::graphics::core::clipboard::DndSource

impl Debug for cosmic::iced::daemon::program::graphics::core::clipboard::Kind

impl Debug for cosmic::iced::daemon::program::graphics::core::event::wayland::Event

impl Debug for LayerEvent

impl Debug for OutputEvent

impl Debug for OverlapNotifyEvent

impl Debug for PopupEvent

impl Debug for SeatEvent

impl Debug for SessionLockEvent

impl Debug for SubsurfaceEvent

impl Debug for cosmic::iced::daemon::program::graphics::core::event::wayland::WindowEvent

impl Debug for A11yId

impl Debug for cosmic::iced::daemon::program::graphics::core::id::Internal

impl Debug for cosmic::iced::daemon::program::graphics::core::input_method::Event

impl Debug for cosmic::iced::daemon::program::graphics::core::input_method::Purpose

impl Debug for cosmic::iced::daemon::program::graphics::core::keyboard::key::Code

impl Debug for cosmic::iced::daemon::program::graphics::core::keyboard::key::Named

impl Debug for cosmic::iced::daemon::program::graphics::core::keyboard::key::NativeCode

impl Debug for cosmic::iced::daemon::program::graphics::core::keyboard::key::Physical

impl Debug for cosmic::iced::daemon::program::graphics::core::layout::flex::Axis

impl Debug for cosmic::iced::daemon::program::graphics::core::mouse::click::Kind

impl Debug for cosmic::iced::daemon::program::graphics::core::svg::Data

impl Debug for cosmic::iced::daemon::program::graphics::core::text::editor::Direction

impl Debug for cosmic::iced::daemon::program::graphics::core::text::Affinity

impl Debug for cosmic::iced::daemon::program::graphics::core::text::Difference

impl Debug for cosmic::iced::daemon::program::graphics::core::text::EllipsizeHeightLimit

impl Debug for cosmic::iced::daemon::program::graphics::core::text::Hit

impl Debug for cosmic::iced::daemon::program::graphics::core::theme::Mode

impl Debug for cosmic::iced::daemon::program::graphics::core::widget::tree::State

impl Debug for cosmic::iced::daemon::program::graphics::core::window::icon::Error

impl Debug for cosmic::iced::daemon::program::graphics::core::window::screenshot::CropError

impl Debug for Antialiasing

impl Debug for cosmic::iced::daemon::program::graphics::Error

impl Debug for cosmic::iced::daemon::program::graphics::Image

impl Debug for Mesh

impl Debug for cosmic::iced::daemon::program::graphics::Text

impl Debug for cosmic::iced::daemon::program::graphics::error::Reason

impl Debug for cosmic::iced::daemon::program::graphics::futures::futures::channel::mpsc::TryRecvError

impl Debug for cosmic::iced::daemon::program::graphics::futures::futures::io::ErrorKind

impl Debug for cosmic::iced::daemon::program::graphics::futures::futures::io::SeekFrom

impl Debug for PollNext

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Action

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Affinity

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Align

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Command

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Ellipsize

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::EllipsizeHeightLimit

impl Debug for FamilyOwned

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Hinting

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::LineEnding

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Motion

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Selection

impl Debug for cosmic::iced::daemon::program::graphics::text::cosmic_text::Shaping

Trait Debug