Trait Display

1.0.0 · Source

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

Expand description

Format trait for an empty format, {}.

Implementing this trait for a type will automatically implement the ToString trait for the type, allowing the usage of the .to_string() method. Prefer implementing the Display trait for a type, rather than ToString.

Display is similar to Debug, but Display is for user-facing output, and so cannot be derived.

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

§Internationalization

Because a type can only have one Display implementation, it is often preferable to only implement Display when there is a single most “obvious” way that values can be formatted as text. This could mean formatting according to the “invariant” culture and “undefined” locale, or it could mean that the type display is designed for a specific culture/locale, such as developer logs.

If not all values have a justifiably canonical textual format or if you want to support alternative formats not covered by the standard set of possible formatting traits, the most flexible approach is display adapters: methods like str::escape_default or Path::display which create a wrapper implementing Display to output the specific display format.

§Examples

Implementing Display on a type:

use std::fmt;

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

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

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

assert_eq!(format!("The origin is: {origin}"), "The origin is: (0, 0)");

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::Display for Position {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "({}, {})", self.longitude, self.latitude)
    }
}

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

Trait DisplayCopy item path

§Internationalization

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Display for BatchInputCreationError

impl Display for batch_mode_3p::FilePurpose

impl Display for GptApiUrl

impl Display for GptModelType

impl Display for HttpMethod

impl Display for JsonRepairError

impl Display for batch_mode_3p::JsonValue

impl Display for batch_mode_3p::OpenAIError

impl Display for AsciiChar

impl Display for Infallible

impl Display for FromBytesWithNulError

impl Display for IpAddr

impl Display for SocketAddr

impl Display for GetDisjointMutError

impl Display for VarError

impl Display for std::sync::mpsc::RecvTimeoutError

impl Display for std::sync::mpsc::TryRecvError

impl Display for async_openai::error::OpenAIError

impl Display for async_openai::types::audio::AudioResponseFormat

impl Display for async_openai::types::audio::AudioResponseFormat

impl Display for async_openai::types::audio::TimestampGranularity

impl Display for async_openai::types::audio::TimestampGranularity

impl Display for ChatCompletionRequestMessageContentPartRefusalBuilderError

impl Display for async_openai::types::chat::Role

impl Display for async_openai::types::chat::Role

impl Display for async_openai::types::file::FilePurpose

impl Display for async_openai::types::image::DallE2ImageSize

impl Display for async_openai::types::image::DallE2ImageSize

impl Display for async_openai::types::image::ImageModel

impl Display for async_openai::types::image::ImageModel

impl Display for ImageResponseFormat

impl Display for async_openai::types::image::ImageSize

impl Display for async_openai::types::image::ImageSize

impl Display for ResponseFormat

impl Display for ParseAlphabetError

impl Display for DecodeError

impl Display for DecodeSliceError

impl Display for EncodeSliceError

impl Display for Shell

impl Display for crossbeam_channel::err::RecvTimeoutError

impl Display for crossbeam_channel::err::TryRecvError

impl Display for httparse::Error

impl Display for humantime::date::Error

impl Display for humantime::duration::Error

impl Display for CodePointInversionListError

impl Display for CodePointInversionListAndStringListError

impl Display for icu_collections::codepointtrie::error::Error

impl Display for ParserError

impl Display for LocaleTransformError

impl Display for NormalizerError

impl Display for PropertiesError

impl Display for DataErrorKind

impl Display for IpNet

impl Display for json5::error::Error

impl Display for log::Level

impl Display for log::LevelFilter

impl Display for rand::distr::bernoulli::BernoulliError

impl Display for rand::distr::uniform::Error

impl Display for rand::distr::weighted::Error

impl Display for rand::distributions::bernoulli::BernoulliError

impl Display for WeightedError

impl Display for StartError

impl Display for regex_syntax::ast::Ast

impl Display for regex_syntax::ast::Ast

impl Display for regex_syntax::ast::ErrorKind

impl Display for regex_syntax::ast::ErrorKind

impl Display for regex_syntax::error::Error

impl Display for regex_syntax::error::Error

impl Display for regex_syntax::hir::ErrorKind

impl Display for regex_syntax::hir::ErrorKind

impl Display for regex::error::Error

impl Display for reqwest_eventsource::error::Error

Trait Display