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.
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§
sourcefn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter.
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 AppDirError
impl Display for DigestError
impl Display for ExecError
impl Display for FileDigestError
impl Display for FileIoError
impl Display for FileOwnerError
impl Display for FromHexError
impl Display for Infallible
impl Display for ModeError
impl Display for ModeParseError
impl Display for Weekday
impl Display for cotton::prelude::io::ErrorKind
impl Display for core::net::ip_addr::IpAddr
impl Display for SocketAddr
impl Display for VarError
impl Display for RecvTimeoutError
impl Display for TryRecvError
impl Display for time::ParseError
impl Display for RoundingError
impl Display for cradle::error::Error
impl Display for exec::Error
impl Display for Level
impl Display for LevelFilter
impl Display for regex::error::Error
impl Display for RenderError
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 cotton::prelude::io::Error
impl Display for WriterPanicked
impl Display for Digest
impl Display for ExitStatus
impl Display for Group
impl Display for Mode
impl Display for Owner
impl Display for FileTime
impl Display for FixedOffset
impl Display for MaybeStr
impl Display for MaybeString
impl Display for MkArgs
impl Display for NaiveDate
The Display output of the naive date d is the same as
d.format("%Y-%m-%d").
The string printed can be readily parsed via the parse method on str.
Example
use chrono::NaiveDate;
assert_eq!(format!("{}", NaiveDate::from_ymd_opt(2015, 9, 5).unwrap()), "2015-09-05");
assert_eq!(format!("{}", NaiveDate::from_ymd_opt( 0, 1, 1).unwrap()), "0000-01-01");
assert_eq!(format!("{}", NaiveDate::from_ymd_opt(9999, 12, 31).unwrap()), "9999-12-31");ISO 8601 requires an explicit sign for years before 1 BCE or after 9999 CE.
assert_eq!(format!("{}", NaiveDate::from_ymd_opt( -1, 1, 1).unwrap()), "-0001-01-01");
assert_eq!(format!("{}", NaiveDate::from_ymd_opt(10000, 12, 31).unwrap()), "+10000-12-31");impl Display for NaiveDateTime
The Display output of the naive date and time dt is the same as
dt.format("%Y-%m-%d %H:%M:%S%.f").
It should be noted that, for leap seconds not on the minute boundary, it may print a representation not distinguishable from non-leap seconds. This doesn’t matter in practice, since such leap seconds never happened. (By the time of the first leap second on 1972-06-30, every time zone offset around the world has standardized to the 5-minute alignment.)
Example
use chrono::NaiveDate;
let dt = NaiveDate::from_ymd_opt(2016, 11, 15).unwrap().and_hms_opt(7, 39, 24).unwrap();
assert_eq!(format!("{}", dt), "2016-11-15 07:39:24");Leap seconds may also be used.
let dt = NaiveDate::from_ymd_opt(2015, 6, 30).unwrap().and_hms_milli_opt(23, 59, 59, 1_500).unwrap();
assert_eq!(format!("{}", dt), "2015-06-30 23:59:60.500");impl Display for NaiveTime
The Display output of the naive time t is the same as
t.format("%H:%M:%S%.f").
The string printed can be readily parsed via the parse method on str.
It should be noted that, for leap seconds not on the minute boundary, it may print a representation not distinguishable from non-leap seconds. This doesn’t matter in practice, since such leap seconds never happened. (By the time of the first leap second on 1972-06-30, every time zone offset around the world has standardized to the 5-minute alignment.)
Example
use chrono::NaiveTime;
assert_eq!(format!("{}", NaiveTime::from_hms_opt(23, 56, 4).unwrap()), "23:56:04");
assert_eq!(format!("{}", NaiveTime::from_hms_milli_opt(23, 56, 4, 12).unwrap()), "23:56:04.012");
assert_eq!(format!("{}", NaiveTime::from_hms_micro_opt(23, 56, 4, 1234).unwrap()), "23:56:04.001234");
assert_eq!(format!("{}", NaiveTime::from_hms_nano_opt(23, 56, 4, 123456).unwrap()), "23:56:04.000123456");Leap seconds may also be used.
assert_eq!(format!("{}", NaiveTime::from_hms_milli_opt(6, 59, 59, 1_500).unwrap()), "06:59:60.500");impl Display for cotton::prelude::ParseFloatError
impl Display for Problem
impl Display for cotton::prelude::Regex
impl Display for StatusError
impl Display for Utc
impl Display for 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 LayoutError
impl Display for AllocError
impl Display for TryFromSliceError
impl Display for core::ascii::EscapeDefault
impl Display for BorrowError
impl Display for BorrowMutError
impl Display for CharTryFromError
impl Display for ParseCharError
impl Display for DecodeUtf16Error
impl Display for core::char::EscapeDebug
impl Display for core::char::EscapeDefault
impl Display for core::char::EscapeUnicode
impl Display for ToLowercase
impl Display for ToUppercase
impl Display for TryFromCharError
impl Display for FromBytesUntilNulError
impl Display for FromBytesWithNulError
impl Display for core::net::ip_addr::Ipv4Addr
impl Display for core::net::ip_addr::Ipv6Addr
Write an Ipv6Addr, conforming to the canonical style described by RFC 5952.
impl Display for AddrParseError
impl Display for SocketAddrV4
impl Display for SocketAddrV6
impl Display for ParseIntError
impl Display for TryFromIntError
impl Display for NonZeroI8
impl Display for NonZeroI16
impl Display for NonZeroI32
impl Display for NonZeroI64
impl Display for NonZeroI128
impl Display for NonZeroIsize
impl Display for NonZeroU8
impl Display for NonZeroU16
impl Display for NonZeroU32
impl Display for NonZeroU64
impl Display for NonZeroU128
impl Display for NonZeroUsize
impl Display for Location<'_>
impl Display for PanicInfo<'_>
impl Display for ParseBoolError
impl Display for Utf8Error
impl Display for TryFromFloatSecsError
impl Display for Backtrace
impl Display for JoinPathsError
impl Display for Display<'_>
impl Display for StripPrefixError
impl Display for ExitStatusError
impl Display for RecvError
impl Display for AccessError
impl Display for SystemTimeError
impl Display for Duration
impl Display for OutOfRangeError
impl Display for SteadyTime
impl Display for Infix
impl Display for Prefix
impl Display for Suffix
impl Display for chrono::format::ParseError
impl Display for ParseWeekdayError
impl Display for InvalidBufferSize
impl Display for InvalidOutputSize
impl Display for ParseLevelError
impl Display for SetLoggerError
impl Display for num_traits::ParseFloatError
impl Display for regex::re_bytes::Regex
impl Display for MismatchedQuotes
impl Display for PathPersistError
impl Display for Arguments<'_>
impl Display for cotton::prelude::fmt::Error
impl Display for Arg
impl Display for Ast
Print a display representation of this Ast.
This does not preserve any of the original whitespace formatting that may have originally been present in the concrete syntax from which this Ast was generated.
This implementation uses constant stack space and heap space proportional
to the size of the Ast.
impl Display for CaseFoldError
impl Display for ClearEnvError
impl Display for ClockId
impl Display for ColorChoice
impl Display for Command
impl Display for ContextKind
impl Display for ContextValue
impl Display for Errno
impl Display for Errno
impl Display for Errno
impl Display for Errno
impl Display for Error
impl Display for Error
impl Display for Error
impl Display for Error
impl Display for Error
impl Display for ErrorKind
impl Display for ErrorKind
impl Display for ErrorKind
impl Display for GetTimezoneError
impl Display for Gid
impl Display for Hir
Print a display representation of this Hir.
The result of this is a valid regular expression pattern string.
This implementation uses constant stack space and heap space proportional
to the size of the Hir.
impl Display for Id
impl Display for InetAddr
impl Display for InvalidLength
impl Display for IpAddr
impl Display for Ipv4Addr
impl Display for Ipv6Addr
impl Display for LinkAddr
impl Display for MatchesError
impl Display for ParseColorError
impl Display for Pid
impl Display for Signal
impl Display for SockAddr
impl Display for SockaddrIn
impl Display for SockaddrIn6
impl Display for SockaddrStorage
impl Display for Str
impl Display for StrSimError
impl Display for StyledStr
Color-unaware printing. Never uses coloring.