Trait alloc::fmt::Display

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

空格式的格式 trait,{}

为一个类型实现这个 trait 将自动为该类型实现 ToString trait,允许使用 .to_string() 方法。 更喜欢为一个类型实现 Display trait,而不是 ToString

DisplayDebug 类似,但 Display 是面向用户的输出,因此无法导出。

有关格式化程序的更多信息,请参见 模块级文档

Examples

在类型上实现 Display

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)");
Run

Required Methods§

source

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

使用给定的格式化程序格式化该值。

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, }));
Run

Implementors§

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impl Display for AsciiChar

1.34.0 · source§

impl Display for Infallible

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impl Display for IpAddr

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impl Display for SocketAddr

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impl Display for bool

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impl Display for char

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impl Display for f32

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impl Display for f64

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impl Display for i8

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impl Display for i16

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impl Display for i32

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impl Display for i64

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impl Display for i128

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impl Display for isize

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impl Display for !

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impl Display for str

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impl Display for u8

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impl Display for u16

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impl Display for u32

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impl Display for u64

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impl Display for u128

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impl Display for usize

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impl Display for TryFromSliceError

1.39.0 · source§

impl Display for core::ascii::EscapeDefault

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impl Display for BorrowError

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impl Display for BorrowMutError

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impl Display for CharTryFromError

1.20.0 · source§

impl Display for ParseCharError

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impl Display for DecodeUtf16Error

1.20.0 · source§

impl Display for core::char::EscapeDebug

1.16.0 · source§

impl Display for core::char::EscapeDefault

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impl Display for core::char::EscapeUnicode

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impl Display for ToLowercase

1.16.0 · source§

impl Display for ToUppercase

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impl Display for TryFromCharError

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impl Display for FromBytesUntilNulError

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impl Display for FromBytesWithNulError

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impl Display for Ipv4Addr

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impl Display for Ipv6Addr

编写一个符合 RFC 5952 描述的规范样式的 Ivv6Addr。

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impl Display for AddrParseError

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impl Display for SocketAddrV4

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impl Display for SocketAddrV6

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impl Display for ParseFloatError

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impl Display for ParseIntError

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impl Display for TryFromIntError

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impl Display for NonZeroI8

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impl Display for NonZeroI16

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impl Display for NonZeroI32

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impl Display for NonZeroI64

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impl Display for NonZeroI128

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impl Display for NonZeroIsize

1.28.0 · source§

impl Display for NonZeroU8

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impl Display for NonZeroU16

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impl Display for NonZeroU32

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impl Display for NonZeroU64

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impl Display for NonZeroU128

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impl Display for NonZeroUsize

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impl Display for Location<'_>

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impl Display for PanicInfo<'_>

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impl Display for TryFromFloatSecsError

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impl Display for AllocError

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impl Display for LayoutError

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impl Display for TryReserveError

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impl Display for FromVecWithNulError

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impl Display for IntoStringError

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impl Display for NulError

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impl Display for ParseBoolError

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impl Display for Utf8Error

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impl Display for FromUtf8Error

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impl Display for FromUtf16Error

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impl Display for String

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impl Display for Arguments<'_>

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impl Display for Error

1.60.0 · source§

impl<'a> Display for EscapeAscii<'a>

1.34.0 · source§

impl<'a> Display for alloc::str::EscapeDebug<'a>

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impl<'a> Display for alloc::str::EscapeDefault<'a>

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impl<'a> Display for alloc::str::EscapeUnicode<'a>

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impl<'a, K: Debug + Ord, V: Debug, A: Allocator + Clone> Display for OccupiedError<'a, K, V, A>

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impl<B> Display for Cow<'_, B>where B: Display + ToOwned<Owned: Display> + ?Sized,

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impl<P> Display for Pin<P>where P: Display,

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impl<T> Display for &Twhere T: Display + ?Sized,

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impl<T> Display for &mut Twhere T: Display + ?Sized,

1.20.0 · source§

impl<T> Display for Ref<'_, T>where T: Display + ?Sized,

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impl<T> Display for RefMut<'_, T>where T: Display + ?Sized,

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impl<T> Display for Saturating<T>where T: Display,

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impl<T> Display for Wrapping<T>where T: Display,

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impl<T: Display + ?Sized, A: Allocator> Display for Box<T, A>

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impl<T: ?Sized + Display> Display for ThinBox<T>

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impl<T: ?Sized + Display> Display for Rc<T>

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impl<T: ?Sized + Display> Display for Arc<T>

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impl<const N: usize> Display for GetManyMutError<N>