Enum Linkage 

pub enum Linkage {
    External,
    Internal,
    Weak,
    LinkOnce,
    Common,
}

How a symbol is seen outside the object it is defined in.

The set is the one C needs and no more. C++ vague linkage and the ODR variants are not here because nothing produces them.

Variants

External

Defined here and visible to every other object. The default, and what a plain definition at file scope gets.

Internal

Defined here and invisible outside it, which is what static at file scope means.

Weak

Defined here, visible, and allowed to be replaced by a strong definition elsewhere. __attribute__((weak)). A reference to one that nothing defines is a null address rather than a link error.

LinkOnce

Defined here, visible, and allowed to be identical to a definition in another object, with one of them kept and the rest discarded. What extern inline under the GNU semantics and a compiler-generated helper get.

Common

A tentative definition, which the linker merges with any other tentative definition of the same name and any real definition. int x; at file scope under -fcommon.

Implementations

impl Linkage

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

The spelling in the textual form.

pub fn from_name(name: &str) -> Option<Self>

The linkage that spelling names.

pub fn all() -> impl Iterator<Item = Self>

Every linkage, in declaration order.

pub const fn is_local(self) -> bool

Whether the symbol is invisible outside this object, so that a pass may rewrite every use of it because it can see every use of it.

pub const fn may_be_replaced(self) -> bool

Whether the definition here may lose to one in another object at link time.

The optimizer must not fold a use against the definition it can see when this is true, because the definition that wins may be a different one.

Trait Implementations

impl Clone for Linkage

fn clone(&self) -> Linkage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Linkage

impl Debug for Linkage

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

Formats the value using the given formatter.

impl Default for Linkage

fn default() -> Linkage

Returns the “default value” for a type.

impl Eq for Linkage

impl Hash for Linkage

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 Linkage

fn cmp(&self, other: &Linkage) -> 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 Linkage

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Linkage

fn partial_cmp(&self, other: &Linkage) -> 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 Linkage