Trait ockam::compat::fmt::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 ockam::compat::fmt::DisplayCopy item path

§Internationalization

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Display for OckamError

impl Display for ockam::migration_20240111100002_delete_trust_context::Expr

impl Display for VaultError

impl Display for SecretAttributes

impl Display for SecretType

impl Display for IpAddr

impl Display for SocketAddr

impl Display for BernoulliError

impl Display for WeightedError

impl Display for ockam::compat::tokio::io::ErrorKind

impl Display for ockam::compat::tokio::sync::broadcast::error::RecvError

impl Display for ockam::compat::tokio::sync::broadcast::error::TryRecvError

impl Display for TryAcquireError

impl Display for ockam::compat::tokio::sync::mpsc::error::TryRecvError

impl Display for ockam::compat::tokio::sync::oneshot::error::TryRecvError

impl Display for AsciiChar

impl Display for Infallible

impl Display for VarError

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

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

impl Display for base16ct::error::Error

impl Display for ParseAlphabetError

impl Display for DecodeError

impl Display for DecodeSliceError

impl Display for EncodeSliceError

impl Display for base64ct::errors::Error

impl Display for RoundingError

impl Display for chrono::weekday::Weekday

impl Display for const_oid::error::Error

impl Display for crossbeam_channel::err::RecvTimeoutError

impl Display for crossbeam_channel::err::TryRecvError

impl Display for der::error::ErrorKind

impl Display for Class

impl Display for der::tag::Tag

impl Display for TagMode

impl Display for flume::RecvError

impl Display for flume::RecvTimeoutError

impl Display for flume::TryRecvError

impl Display for FromHexError

impl Display for GetTimezoneError

impl Display for leb128::read::Error

impl Display for log::Level

impl Display for log::LevelFilter

impl Display for MietteError

impl Display for Type

impl Display for BooleanExpr

impl Display for EvalError

impl Display for ockam_abac::error::ParseError

impl Display for ockam_abac::expr::Expr

impl Display for PolicyExpression

impl Display for ResourceType

impl Display for Action

impl Display for Method

impl Display for Status

impl Display for RouteError

impl Display for IdentityError

impl Display for NodeError

impl Display for NodeReason

impl Display for RouterReason

impl Display for WorkerReason

impl Display for NodeMessage

impl Display for TransportError

impl Display for TcpConnectionMode

impl Display for Array

impl Display for opentelemetry::common::Value

impl Display for opentelemetry::global::error_handler::Error

impl Display for LogError

impl Display for MetricsError

impl Display for TraceError

impl Display for Aggregation

impl Display for opentelemetry_sdk::runtime::TrySendError

impl Display for pem_rfc7468::error::Error

Trait ockam::compat::fmt::Display