loam_sdk::soroban_sdk::testutils::arbitrary::std::fmt

Trait 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,
)");

Debug

Trait Debug Copy item path

§Stability

§Examples

Required Methods§

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

§Errors

§Examples

Implementors§

impl Debug for InvokeError

impl Debug for AccountEntryExt

impl Debug for AccountEntryExtensionV1Ext

impl Debug for AccountEntryExtensionV2Ext

impl Debug for AccountFlags

impl Debug for AccountMergeResult

impl Debug for AccountMergeResultCode

impl Debug for AllowTrustResult

impl Debug for AllowTrustResultCode

impl Debug for ArchivalProofBody

impl Debug for ArchivalProofType

impl Debug for Asset

impl Debug for AssetCode

impl Debug for AssetType

impl Debug for AuthenticatedMessage

impl Debug for BeginSponsoringFutureReservesResult

impl Debug for BeginSponsoringFutureReservesResultCode

impl Debug for BinaryFuseFilterType

impl Debug for BucketEntry

impl Debug for BucketEntryType

impl Debug for BucketListType

impl Debug for BucketMetadataExt

impl Debug for BumpSequenceResult

impl Debug for BumpSequenceResultCode

impl Debug for ChangeTrustAsset

impl Debug for ChangeTrustResult

impl Debug for ChangeTrustResultCode

impl Debug for ClaimAtom

impl Debug for ClaimAtomType

impl Debug for ClaimClaimableBalanceResult

impl Debug for ClaimClaimableBalanceResultCode

impl Debug for ClaimPredicate

impl Debug for ClaimPredicateType

impl Debug for ClaimableBalanceEntryExt

impl Debug for ClaimableBalanceEntryExtensionV1Ext

impl Debug for ClaimableBalanceFlags

impl Debug for ClaimableBalanceId

impl Debug for ClaimableBalanceIdType

impl Debug for Claimant

impl Debug for ClaimantType

impl Debug for ClawbackClaimableBalanceResult

impl Debug for ClawbackClaimableBalanceResultCode

impl Debug for ClawbackResult

impl Debug for ClawbackResultCode

impl Debug for ColdArchiveBucketEntry

impl Debug for ColdArchiveBucketEntryType

impl Debug for ConfigSettingEntry

impl Debug for ConfigSettingId

impl Debug for ContractCodeEntryExt

impl Debug for ContractCostType

impl Debug for ContractDataDurability

impl Debug for ContractEventBody

impl Debug for ContractEventType

impl Debug for ContractExecutable

impl Debug for ContractExecutableType

impl Debug for ContractIdPreimage

impl Debug for ContractIdPreimageType

impl Debug for CreateAccountResult

impl Debug for CreateAccountResultCode

impl Debug for CreateClaimableBalanceResult

impl Debug for CreateClaimableBalanceResultCode

impl Debug for CryptoKeyType

impl Debug for DataEntryExt

impl Debug for EndSponsoringFutureReservesResult

impl Debug for EndSponsoringFutureReservesResultCode

impl Debug for EnvelopeType

impl Debug for loam_sdk::soroban_sdk::xdr::Error

impl Debug for ErrorCode

impl Debug for ExtendFootprintTtlResult

impl Debug for ExtendFootprintTtlResultCode

impl Debug for ExtensionPoint

Trait Debug