Trait floresta_common::prelude::fmt::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 floresta_common::prelude::fmt::Debug

Required Methods§

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

Implementors§

impl Debug for base58ck::error::Error

impl Debug for bech32::DecodeError

impl Debug for bech32::EncodeError

impl Debug for EncodeIoError

impl Debug for CharError

impl Debug for CheckedHrpstringError

impl Debug for ChecksumError

impl Debug for PaddingError

impl Debug for SegwitHrpstringError

impl Debug for UncheckedHrpstringError

impl Debug for FromCharError

impl Debug for bech32::primitives::gf32::TryFromError

impl Debug for bech32::primitives::hrp::Error

impl Debug for WitnessLengthError

impl Debug for bech32::segwit::EncodeError

impl Debug for AddressData

impl Debug for AddressType

impl Debug for KnownHrp

impl Debug for NetworkChecked

impl Debug for NetworkUnchecked

impl Debug for FromScriptError

impl Debug for P2shError

impl Debug for bitcoin::address::error::ParseError

impl Debug for ChildNumber

impl Debug for bitcoin::bip32::Error

impl Debug for bitcoin::bip152::Error

impl Debug for bitcoin::bip158::Error

impl Debug for Bip34Error

impl Debug for ValidationError

impl Debug for bitcoin::blockdata::locktime::absolute::LockTime

impl Debug for bitcoin::blockdata::locktime::relative::LockTime

impl Debug for Class

impl Debug for ClassifyContext

impl Debug for bitcoin::blockdata::script::Error

impl Debug for bitcoin::blockdata::script::witness_program::Error

impl Debug for FromStrError

impl Debug for TryFromInstructionError

impl Debug for WitnessVersion

impl Debug for ParseOutPointError

impl Debug for bitcoin::consensus::encode::Error

impl Debug for FromHexError

impl Debug for TxVerifyError

impl Debug for bitcoin::crypto::ecdsa::Error

impl Debug for bitcoin::crypto::key::FromSliceError

impl Debug for FromWifError

impl Debug for ParseCompressedPublicKeyError

impl Debug for ParsePublicKeyError

impl Debug for AnnexError

impl Debug for EcdsaSighashType

impl Debug for P2wpkhError

impl Debug for PrevoutsIndexError

impl Debug for TapSighashType

impl Debug for bitcoin::crypto::sighash::TaprootError

impl Debug for SigFromSliceError

impl Debug for PrefixedHexError

impl Debug for UnprefixedHexError

impl Debug for MerkleBlockError

impl Debug for Network

impl Debug for NetworkKind

impl Debug for AddrV2

impl Debug for NetworkMessage

impl Debug for Inventory

impl Debug for BloomFlags

impl Debug for RejectReason

impl Debug for ExtractTxError

impl Debug for GetKeyError

impl Debug for bitcoin::psbt::IndexOutOfBoundsError

impl Debug for KeyRequest

impl Debug for OutputType

impl Debug for SignError

impl Debug for SigningAlgorithm

impl Debug for SigningKeys

impl Debug for bitcoin::psbt::error::Error

impl Debug for MessageSignatureError

impl Debug for HiddenNodesError

impl Debug for IncompleteBuilderError