Enum Effect 

pub enum Effect {
    Pure,
    Faults,
    Allocates,
    AllocatesAndFaults,
}

The one answer to “does calling this need a root set, or a fault check?”

Allocates means the call may trigger a collection, so every live GcRef the caller holds must be rooted across it — that is what makes a call site a safepoint. A wrapper that only hands back an immortal singleton (true, false, unit) allocates nothing collectable and is therefore not a safepoint, however “alloc” its name reads.

Variants

Pure

Neither allocates nor faults.

Faults

May set a pending fault; cannot allocate.

Allocates

May allocate (and therefore collect); cannot fault.

AllocatesAndFaults

Both.

Implementations

impl Effect

pub const fn allocates(self) -> bool

Whether a call to this symbol is a safepoint.

pub const fn faults(self) -> bool

Whether a call to this symbol needs a fault check afterwards.

Trait Implementations

impl Clone for Effect

fn clone(&self) -> Effect

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Effect

impl Debug for Effect

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

Formats the value using the given formatter.

impl Eq for Effect

impl Hash for Effect

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 PartialEq for Effect

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Effect