layer_shika::wayland_client::backend::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,
)");

Trait DebugCopy item path

§Stability

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Debug for layer_shika::sctk::calloop::Error

impl Debug for layer_shika::sctk::calloop::Mode

impl Debug for PostAction

impl Debug for TimeoutAction

impl Debug for CursorIcon

impl Debug for FrameAction

impl Debug for FrameClick

impl Debug for layer_shika::sctk::csd_frame::ResizeEdge

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_device_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_device_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_offer_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_source_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::data_control::v1::client::ext_data_control_source_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::foreign_toplevel_list::v1::client::ext_foreign_toplevel_handle_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::foreign_toplevel_list::v1::client::ext_foreign_toplevel_list_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::idle_notify::v1::client::ext_idle_notification_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::idle_notify::v1::client::ext_idle_notifier_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_capture_source::v1::client::ext_foreign_toplevel_image_capture_source_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_capture_source::v1::client::ext_image_capture_source_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_capture_source::v1::client::ext_output_image_capture_source_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_cursor_session_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_cursor_session_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_frame_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_frame_v1::Event

impl Debug for FailureReason

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_manager_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_session_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::image_copy_capture::v1::client::ext_image_copy_capture_session_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::session_lock::v1::client::ext_session_lock_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::session_lock::v1::client::ext_session_lock_surface_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::session_lock::v1::client::ext_session_lock_surface_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::session_lock::v1::client::ext_session_lock_v1::Error

impl Debug for layer_shika::sctk::protocols::ext::session_lock::v1::client::ext_session_lock_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::transient_seat::v1::client::ext_transient_seat_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::transient_seat::v1::client::ext_transient_seat_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::workspace::v1::client::ext_workspace_group_handle_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::workspace::v1::client::ext_workspace_handle_v1::Event

impl Debug for layer_shika::sctk::protocols::ext::workspace::v1::client::ext_workspace_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::alpha_modifier::v1::client::wp_alpha_modifier_surface_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::alpha_modifier::v1::client::wp_alpha_modifier_surface_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::alpha_modifier::v1::client::wp_alpha_modifier_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::alpha_modifier::v1::client::wp_alpha_modifier_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_management_output_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_management_surface_feedback_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_management_surface_feedback_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_management_surface_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_management_surface_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_manager_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_manager_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_manager_v1::Feature

impl Debug for Primaries

impl Debug for RenderIntent

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_color_manager_v1::TransferFunction

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_creator_icc_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_creator_icc_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_creator_params_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_creator_params_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_info_v1::Event

impl Debug for Cause

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_management::v1::client::wp_image_description_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_representation::v1::client::wp_color_representation_manager_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_representation::v1::client::wp_color_representation_manager_v1::Event

impl Debug for AlphaMode

impl Debug for ChromaLocation

impl Debug for Coefficients

impl Debug for layer_shika::sctk::protocols::wp::color_representation::v1::client::wp_color_representation_surface_v1::Error

impl Debug for layer_shika::sctk::protocols::wp::color_representation::v1::client::wp_color_representation_surface_v1::Event

impl Debug for layer_shika::sctk::protocols::wp::color_representation::v1::client::wp_color_representation_surface_v1::Range

impl Debug for layer_shika::sctk::protocols::wp::commit_timing::v1::client::wp_commit_timer_v1::Error

Trait Debug