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 tendermint::crypto::signature::Error

impl Display for ErrorDetail

impl Display for Hash

impl Display for Algorithm

impl Display for Type

impl Display for AsciiChar

impl Display for Infallible

impl Display for IpAddr

impl Display for SocketAddr

impl Display for VarError

impl Display for ErrorKind

impl Display for RecvTimeoutError

impl Display for TryRecvError

impl Display for ed25519_consensus::error::Error

impl Display for FromHexError

impl Display for Value

impl Display for subtle_encoding::error::Error

impl Display for bool

impl Display for char

impl Display for f32

impl Display for f64

impl Display for i8

impl Display for i16

impl Display for i32

impl Display for i64

impl Display for i128

impl Display for isize

impl Display for !

impl Display for str

impl Display for u8

impl Display for u16

impl Display for u32

impl Display for u64

impl Display for u128

impl Display for usize

impl Display for tendermint::account::Id

impl Display for Height

impl Display for tendermint::block::Id

impl Display for Round

impl Display for tendermint::chain::id::Id

impl Display for Channels

impl Display for VerificationKey

impl Display for BlockIdFlagSubdetail

impl Display for CryptoSubdetail

impl Display for DateOutOfRangeSubdetail

impl Display for DurationOutOfRangeSubdetail

impl Display for EmptySignatureSubdetail

impl Display for tendermint::error::Errorwhere DefaultTracer: Debug,

impl Display for IntegerOverflowSubdetail

impl Display for InvalidAbciRequestTypeSubdetail

impl Display for InvalidAbciResponseTypeSubdetail

impl Display for InvalidAccountIdLengthSubdetail

impl Display for InvalidAppHashLengthSubdetail

impl Display for InvalidBlockSubdetail

impl Display for InvalidEvidenceSubdetail

impl Display for InvalidFirstHeaderSubdetail

impl Display for InvalidHashSizeSubdetail

impl Display for InvalidKeySubdetail

impl Display for InvalidMessageTypeSubdetail

impl Display for InvalidPartSetHeaderSubdetail

impl Display for InvalidSignatureIdLengthSubdetail

impl Display for InvalidSignatureSubdetail

impl Display for InvalidSignedHeaderSubdetail

impl Display for InvalidTimestampSubdetail

impl Display for InvalidValidatorAddressSubdetail

impl Display for InvalidValidatorParamsSubdetail

impl Display for InvalidVersionParamsSubdetail

impl Display for LengthSubdetail

impl Display for MissingConsensusParamsSubdetail

impl Display for MissingDataSubdetail

impl Display for MissingEvidenceSubdetail

impl Display for MissingGenesisTimeSubdetail

Trait Display

impl Display for tendermint::error::Error
where DefaultTracer: Debug,