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 · sourcefn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
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, }),
);Implementors§
impl Display for kvarn::encryption::Error
impl Display for IpAddr
impl Display for SocketAddr
impl Display for VarError
impl Display for std::sync::mpsc::RecvTimeoutError
impl Display for std::sync::mpsc::TryRecvError
impl Display for log::Level
impl Display for log::LevelFilter
impl Display for Variant
impl Display for BernoulliError
impl Display for WeightedError
impl Display for AsciiChar
impl Display for Infallible
impl Display for ToCompactStringError
impl Display for ErrorKind
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 Id
impl Display for OffsetDateTime
impl Display for UnorderedKeyError
impl Display for alloc::collections::TryReserveError
impl Display for FromVecWithNulError
impl Display for IntoStringError
impl Display for NulError
impl Display for FromUtf8Error
impl Display for FromUtf16Error
impl Display for String
impl Display for Backtrace
impl Display for JoinPathsError
impl Display for std::ffi::os_str::Display<'_>
impl Display for PanicHookInfo<'_>
impl Display for std::path::Display<'_>
impl Display for StripPrefixError
impl Display for ExitStatus
impl Display for ExitStatusError
impl Display for std::sync::mpsc::RecvError
impl Display for AccessError
impl Display for SystemTimeError
impl Display for FixedBitSet
impl Display for CompressError
impl Display for flate2::mem::DecompressError
impl Display for getrandom::error::Error
impl Display for log::ParseLevelError
impl Display for SetLoggerError
impl Display for FromStrError
impl Display for uuid::error::Error
impl Display for Braced
impl Display for Hyphenated
impl Display for Simple
impl Display for Urn
impl Display for Uuid
impl Display for rand::rngs::adapter::read::ReadError
impl Display for rand_core::error::Error
impl Display for Mime
impl Display for CompactString
impl Display for HeaderName
impl Display for Method
impl Display for StatusCode
Formats the status code, including the canonical reason.
§Example
assert_eq!(format!("{}", StatusCode::OK), "200 OK");impl Display for Uri
impl Display for AllocError
impl Display for LayoutError
impl Display for kvarn::prelude::utils::prelude::compact_str::core::array::TryFromSliceError
impl Display for kvarn::prelude::utils::prelude::compact_str::core::ascii::EscapeDefault
impl Display for BorrowError
impl Display for BorrowMutError
impl Display for CharTryFromError
impl Display for DecodeUtf16Error
impl Display for kvarn::prelude::utils::prelude::compact_str::core::char::EscapeDebug
impl Display for kvarn::prelude::utils::prelude::compact_str::core::char::EscapeDefault
impl Display for kvarn::prelude::utils::prelude::compact_str::core::char::EscapeUnicode
impl Display for ParseCharError
impl Display for ToLowercase
impl Display for ToUppercase
impl Display for TryFromCharError
impl Display for FromBytesUntilNulError
impl Display for FromBytesWithNulError
impl Display for ParseFloatError
impl Display for kvarn::prelude::utils::prelude::compact_str::core::num::ParseIntError
impl Display for kvarn::prelude::utils::prelude::compact_str::core::num::TryFromIntError
impl Display for Location<'_>
impl Display for PanicInfo<'_>
impl Display for PanicMessage<'_>
impl Display for TryFromFloatSecsError
impl Display for Drain<'_>
impl Display for ReserveError
impl Display for Utf16Error
impl Display for Arguments<'_>
impl Display for kvarn::prelude::utils::prelude::fmt::Error
impl Display for InvalidHeaderName
impl Display for InvalidHeaderValue
impl Display for MaxSizeReached
impl Display for ToStrError
impl Display for kvarn::prelude::utils::prelude::io::Error
impl Display for WriterPanicked
impl Display for kvarn::prelude::utils::prelude::net::AddrParseError
impl Display for Ipv4Addr
impl Display for Ipv6Addr
Writes an Ipv6Addr, conforming to the canonical style described by RFC 5952.
impl Display for SocketAddrV4
impl Display for SocketAddrV6
impl Display for ParseBoolError
impl Display for Utf8Error
impl Display for Authority
impl Display for InvalidUri
impl Display for InvalidUriParts
impl Display for PathAndQuery
impl Display for Scheme
impl Display for Aborted
impl Display for AcquireError
impl Display for AddrParseError
impl Display for AnyDelimiterCodecError
impl Display for ApplicationClose
impl Display for Canceled
impl Display for CapacityError
impl Display for CloseCode
impl Display for ClosedStream
impl Display for Code
impl Display for CollectionAllocErr
impl Display for ComponentRange
impl Display for ConfigError
impl Display for ConnectError
impl Display for ConnectionClose
impl Display for ConnectionError
impl Display for ConnectionError
impl Display for ConnectionId
impl Display for ContentSizeError
impl Display for Control
impl Display for ConversionRange
impl Display for Data
impl Display for Date
impl Display for DecodeError
impl Display for DecodeSliceError
impl Display for DecompressError
Available on crate feature
with-alloc only.impl Display for DifferentVariant
impl Display for Dir
impl Display for Duration
The format returned by this implementation is not stable and must not be relied upon.
By default this produces an exact, full-precision printout of the duration.
For a concise, rounded printout instead, you can use the .N format specifier:
let duration = Duration::new(123456, 789011223);
println!("{duration:.3}");For the purposes of this implementation, a day is exactly 24 hours and a minute is exactly 60 seconds.