Enum Os 

pub enum Os {
    Linux,
    MacOs,
    IOs,
    Windows,
    FreeBsd,
    NetBsd,
    OpenBsd,
    Illumos,
    Wasi,
    None,
}

An operating system, in the sense of the thing that defines the syscall interface, the object format, the start files and the availability of a declaration.

Android is not here. It is a Linux kernel with a different libc, so it is Os::Linux with Env::Android, which is also how GCC and LLVM spell it. The rule is that the OS field answers “whose kernel” and the environment field answers “whose libc”, and Android is the case that shows they are separate questions.

Variants

Linux

Linux. Every libc in the environment field is reachable from here.

MacOs

macOS.

IOs

iOS. A different OS from macOS and not a variant of it: a different platform value in LC_BUILD_VERSION, a different set of availability macros, and a different SDK.

Windows

Windows, either environment.

FreeBsd

FreeBSD 14 and later.

NetBsd

NetBSD 10.1 and later.

OpenBsd

OpenBSD. Dynamically linked libc only, because OpenBSD does not ship a static one and breaks its libc ABI on purpose at every release.

Illumos

illumos. In scope because it is open, which is the whole of the argument.

Wasi

WASI. The preview number lives in the OS version, because wasip1 and wasip3 are different ABIs rather than different releases of one.

None

No operating system. Freestanding, which is the kernel target and the embedded target and the only row in the matrix that has to reach tier 1 without a libc.

Implementations

impl Os

pub const fn as_str(self) -> &'static str

The canonical name, without the version.

pub const fn object_format(self) -> Option<ObjectFormat>

The object format this OS uses. There is exactly one per OS, which is why this is a function of the OS and not a field anybody sets.

The freestanding case is the exception and it is handled in crate::TargetTuple, because a freestanding target’s format follows its architecture: a wasm freestanding target emits wasm and an aarch64 one emits ELF.

pub const fn is_darwin(self) -> bool

Whether this is one of the Darwin systems, which share a kernel, a linker, a set of ABI divergences from AAPCS64 and a licence that stops us shipping their headers.

pub const fn has_selectable_libc(self) -> bool

Whether a program on this OS is linked against a libc that the tuple names.

False for Darwin and Windows-MSVC in the sense that matters here: the system C library is not a choice the user makes, so the environment field is carrying something else.

pub const fn default_env(self) -> Env

The environment used when the tuple does not name one.

Windows defaults to gnu rather than msvc, and that is a decision rather than an oversight. spec/cross-compile/04-target-matrix.md puts x86_64-windows-gnu at tier 1 and x86_64-windows-msvc at tier 2 because mingw-w64 is the one we are allowed to ship, and a default that requires the user to fetch a Microsoft SDK is a default that fails on a fresh machine.

pub const fn takes_version(self) -> bool

Whether an OS version in the tuple means something here.

Darwin has a deployment target that decides which declarations exist, and WASI has a preview number that decides the ABI. Everywhere else the version that matters belongs to the libc and lives in the environment version instead.

Trait Implementations

impl Clone for Os

fn clone(&self) -> Os

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Os

impl Debug for Os

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

Formats the value using the given formatter.

impl Display for Os

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

Formats the value using the given formatter.

impl Eq for Os

impl Hash for Os

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 Os

fn cmp(&self, other: &Os) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Os

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Os

fn partial_cmp(&self, other: &Os) -> 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 StructuralPartialEq for Os