Enum Edition

pub enum Edition {
    Edition2015,
    Edition2018,
    Edition2021,
    Edition2024,
}

The edition of the compiler (RFC 2052)

The following sections will guide you how to add and stabilize an edition.

Adding a new edition

• Add the next edition to the enum.
• Update every match expression that now fails to compile.
• Update the FromStr impl.
• Update CLI_VALUES to include the new edition.
• Set LATEST_UNSTABLE to Some with the new edition.
• Add an unstable feature to the features! macro invocation below for the new edition.
• Gate on that new feature in toml.
• Update the shell completion files.
• Update any failing tests (hopefully there are very few).
• Update unstable.md to add a new section for this new edition (see this example).

Stabilization instructions

• Set LATEST_UNSTABLE to None.
• Set LATEST_STABLE to the new version.
• Update is_stable to true.
• Set first_version to the version it will be released.
• Set the editionNNNN feature to stable in the features! macro invocation below.
• Update any tests that are affected.
• Update the man page for the --edition flag.
• Update unstable.md to move the edition section to the bottom.
• Update the documentation:
  • Update any features impacted by the edition.
  • Update manifest.md#the-edition-field.
  • Update the --edition flag (options-new.md).
  • Rebuild man pages.

Variants

Edition2015

The 2015 edition

Edition2018

The 2018 edition

Edition2021

The 2021 edition

Edition2024

The 2024 edition

Implementations

impl Edition

pub const LATEST_UNSTABLE: Option<Edition> = None

The latest edition that is unstable.

This is None if there is no next unstable edition.

pub const LATEST_STABLE: Edition = Edition::Edition2024

The latest stable edition.

pub const ALL: &'static [Edition]

pub const CLI_VALUES: [&'static str; 4]

Possible values allowed for the --edition CLI flag.

This requires a static value due to the way clap works, otherwise I would have built this dynamically.

pub(crate) fn first_version(&self) -> Option<Version>

Returns the first version that a particular edition was released on stable.

pub fn is_stable(&self) -> bool

Returns true if this edition is stable in this release.

pub fn previous(&self) -> Option<Edition>

Returns the previous edition from this edition.

Returns None for 2015.

pub fn saturating_next(&self) -> Edition

Returns the next edition from this edition, returning the last edition if this is already the last one.

pub(crate) fn cmd_edition_arg(&self, cmd: &mut ProcessBuilder)

Updates the given ProcessBuilder to include the appropriate flags for setting the edition.

pub(crate) fn supports_compat_lint(&self) -> bool

Whether or not this edition supports the rust_*_compatibility lint.

Ideally this would not be necessary, but editions may not have any lints, and thus rustc doesn’t recognize it. Perhaps rustc could create an empty group instead?

pub(crate) fn supports_idiom_lint(&self) -> bool

Whether or not this edition supports the rust_*_idioms lint.

Ideally this would not be necessary…

pub(crate) fn default_resolve_behavior(&self) -> ResolveBehavior

Trait Implementations

impl Clone for Edition

fn clone(&self) -> Edition

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Edition

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

Formats the value using the given formatter.

impl Default for Edition

fn default() -> Edition

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Edition

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Edition

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

Formats the value using the given formatter.

impl FromStr for Edition

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Error>

Parses a string s to return a value of this type.

impl Hash for Edition

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Edition

fn cmp(&self, other: &Edition) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Edition

fn eq(&self, other: &Edition) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Edition

fn partial_cmp(&self, other: &Edition) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Edition

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Edition

impl Eq for Edition

impl StructuralPartialEq for Edition

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 1 byte

Size for each variant:

• Edition2015: 0 bytes
• Edition2018: 0 bytes
• Edition2021: 0 bytes
• Edition2024: 0 bytes