Trait snarkvm_debug::prelude::boolean::Debug

1.0.0 · source ·

pub trait Debug {
    // Required method
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}

Expand description

? formatting.

Debug should format the output in a programmer-facing, debugging context.

Generally speaking, you should just derive a Debug implementation.

When used with the alternate format specifier #?, the output is pretty-printed.

For more information on formatters, see the module-level documentation.

This trait can be used with #[derive] if all fields implement Debug. When derived for structs, it will use the name of the struct, then {, then a comma-separated list of each field’s name and Debug value, then }. For enums, it will use the name of the variant and, if applicable, (, then the Debug values of the fields, then ).

Stability

Derived Debug formats are not stable, and so may change with future Rust versions. Additionally, Debug implementations of types provided by the standard library (std, core, alloc, etc.) are not stable, and may also change with future Rust versions.

Examples

Deriving an implementation:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {origin:?}"), "The origin is: Point { x: 0, y: 0 }");

Manually implementing:

use std::fmt;

struct Point {
    x: i32,
    y: i32,
}

impl fmt::Debug for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Point")
         .field("x", &self.x)
         .field("y", &self.y)
         .finish()
    }
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {origin:?}"), "The origin is: Point { x: 0, y: 0 }");

There are a number of helper methods on the Formatter struct to help you with manual implementations, such as debug_struct.

Types that do not wish to use the standard suite of debug representations provided by the Formatter trait (debug_struct, debug_tuple, debug_list, debug_set, debug_map) can do something totally custom by manually writing an arbitrary representation to the Formatter.

impl fmt::Debug for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Point [{} {}]", self.x, self.y)
    }
}

Debug implementations using either derive or the debug builder API on Formatter support pretty-printing using the alternate flag: {:#?}.

Pretty-printing with #?:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {origin:#?}"),
"The origin is: Point {
    x: 0,
    y: 0,
}");

Required Methods§

source

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::Debug for Position {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("")
         .field(&self.longitude)
         .field(&self.latitude)
         .finish()
    }
}

let position = Position { longitude: 1.987, latitude: 2.983 };
assert_eq!(format!("{position:?}"), "(1.987, 2.983)");

assert_eq!(format!("{position:#?}"), "(
    1.987,
    2.983,
)");

Trait snarkvm_debug::prelude::boolean::Debug

Stability

Examples

Required Methods§

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

Examples

Implementors§

impl Debug for snarkvm_debug::cli::Command

impl Debug for UpdaterError

impl Debug for snarkvm_debug::prelude::address::bech32::Error

impl Debug for Variant

impl Debug for snarkvm_debug::prelude::address::fmt::Alignment

impl Debug for SearchStep

impl Debug for LiteralType

impl Debug for FinalizeMode

impl Debug for snarkvm_debug::prelude::string::Ordering

impl Debug for TryReserveErrorKind

impl Debug for AsciiChar

impl Debug for Infallible

impl Debug for c_void

impl Debug for core::net::ip_addr::IpAddr

impl Debug for Ipv6MulticastScope

impl Debug for core::net::socket_addr::SocketAddr

impl Debug for FpCategory

impl Debug for IntErrorKind

impl Debug for core::sync::atomic::Ordering

impl Debug for BacktraceStatus

impl Debug for VarError

impl Debug for std::io::SeekFrom

impl Debug for std::io::error::ErrorKind

impl Debug for Shutdown

impl Debug for AncillaryError

impl Debug for BacktraceStyle

impl Debug for RecvTimeoutError

impl Debug for std::sync::mpsc::TryRecvError

impl Debug for _Unwind_Reason_Code

impl Debug for AnsiColor

impl Debug for anstyle::color::Color

impl Debug for bincode::error::ErrorKind

impl Debug for colored::color::Color

impl Debug for colored::style::Styles

impl Debug for HttpVersion

impl Debug for InfoType

impl Debug for IpResolve

impl Debug for NetRc

impl Debug for ProxyType

impl Debug for curl::easy::handler::ReadError

impl Debug for SeekResult

impl Debug for curl::easy::handler::SslVersion

impl Debug for TimeCondition

impl Debug for WriteError

impl Debug for dotenvy::errors::Error

impl Debug for FlushCompress

impl Debug for FlushDecompress

impl Debug for flate2::mem::Status

impl Debug for FromHexError

impl Debug for IpAddrRange

impl Debug for IpNet

impl Debug for IpSubnets

impl Debug for itertools::with_position::Position

impl Debug for log::Level

impl Debug for log::LevelFilter

impl Debug for native_tls::Protocol

impl Debug for Sign

impl Debug for num_format::error_kind::ErrorKind

impl Debug for Grouping

impl Debug for Locale

impl Debug for FloatErrorKind

impl Debug for ShutdownResult

impl Debug for parking_lot::once::OnceState

impl Debug for BernoulliError

impl Debug for WeightedError

impl Debug for IndexVec

impl Debug for IndexVecIntoIter

impl Debug for Always

impl Debug for EndPoint

impl Debug for ArchiveKind

impl Debug for self_update::Compression

impl Debug for self_update::Status

impl Debug for self_update::errors::Error