Trait gclient::ext::sp_runtime::traits::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 };

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

Required Methods§

1.0.0 · source

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::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 gclient::ext::sp_runtime::traits::DebugCopy item path

§Stability

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Debug for CodeError

impl Debug for CodecError

impl Debug for DataSectionError

impl Debug for ExportError

impl Debug for ImportError

impl Debug for gear_core::code::errors::MemoryError

impl Debug for SectionError

impl Debug for SectionName

impl Debug for StackEndError

impl Debug for TableSectionError

impl Debug for CostToken

impl Debug for ChargeError

impl Debug for ChargeResult

impl Debug for CounterType

impl Debug for LockId

impl Debug for gear_core::memory::AllocError

impl Debug for gear_core::memory::MemoryError

impl Debug for MemorySetupError

impl Debug for gear_core::message::common::MessageDetails

impl Debug for gear_core::message::DispatchKind

impl Debug for MessageWaitedType

impl Debug for gear_core::program::ProgramState

impl Debug for GasReservationState

impl Debug for gear_core_errors::ExecutionError

impl Debug for ExtError

impl Debug for gear_core_errors::MemoryError

impl Debug for MessageError

impl Debug for ReservationError

impl Debug for gear_core_errors::simple::ErrorReplyReason

impl Debug for gear_core_errors::simple::ReplyCode

impl Debug for gear_core_errors::simple::SignalCode

impl Debug for gear_core_errors::simple::SimpleExecutionError

impl Debug for gear_core_errors::simple::SimpleProgramCreationError

impl Debug for gear_core_errors::simple::SuccessReplyReason

impl Debug for gsdk::backtrace::BacktraceStatus

impl Debug for gsdk::Program

impl Debug for gsdk::result::Error

impl Debug for TxError

impl Debug for gclient::DispatchStatus

impl Debug for gclient::Error

impl Debug for gclient::Event

impl Debug for gclient::GearEvent

impl Debug for gclient::errors::BagsList

impl Debug for gclient::errors::Balances

impl Debug for gclient::errors::ConvictionVoting

impl Debug for gclient::errors::Gear

impl Debug for gclient::errors::GearDebug

impl Debug for gclient::errors::GearStakingRewards

impl Debug for gclient::errors::Grandpa

impl Debug for gclient::errors::Identity

impl Debug for gclient::errors::ImOnline

impl Debug for gclient::errors::ModuleError

impl Debug for gclient::errors::Preimage

impl Debug for gclient::errors::RanckedCollective

impl Debug for gclient::errors::Referenda

impl Debug for gclient::errors::Scheduler

impl Debug for gclient::errors::Session

impl Debug for gclient::errors::Staking

impl Debug for gclient::errors::Sudo

impl Debug for gclient::errors::System

impl Debug for gclient::errors::Treasury

impl Debug for gclient::errors::Utility

impl Debug for gclient::errors::Vesting

impl Debug for gclient::errors::Whitelist

impl Debug for gclient::metadata::bags_list::Event

impl Debug for gclient::metadata::balances::Event

impl Debug for gclient::metadata::bounties::Event

impl Debug for gclient::metadata::child_bounties::Event

impl Debug for gclient::metadata::conviction_voting::Event

impl Debug for gclient::metadata::election_provider_multi_phase::Event

impl Debug for gclient::metadata::DispatchError

impl Debug for gclient::metadata::fellowship_collective::Event

Trait gclient::ext::sp_runtime::traits::Debug