enum PermissionPriv {
    ReservedFrz {
        conflicted: bool,
    },
    ReservedIM,
    Active,
    Frozen,
    Disabled,
}
Expand description

The activation states of a pointer.

Variants§

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ReservedFrz

represents: a local mutable reference that has not yet been written to; allows: child reads, foreign reads; affected by: child writes (becomes Active), rejects: foreign writes (Disabled).

ReservedFrz is mostly for types that are Freeze (no interior mutability). If the type has interior mutability, see ReservedIM instead. (Note: since the discovery of tests/fail/tree_borrows/reservedim_spurious_write.rs, we also use ReservedFreeze for mutable references that were retagged with a protector independently of interior mutability)

special case: behaves differently when protected, which is where conflicted is relevant

  • conflicted is set on foreign reads,
  • conflicted must not be set on child writes (there is UB otherwise).

This is so that the behavior of Reserved adheres to the rules of noalias:

  • foreign-read then child-write is UB due to conflicted,
  • child-write then foreign-read is UB since child-write will activate and then foreign-read disables a protected Active, which is UB.

Fields

§conflicted: bool
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ReservedIM

Alternative version of ReservedFrz made for types with interior mutability. allows: child reads, foreign reads, foreign writes (extra); affected by: child writes (becomes Active); rejects: nothing.

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Active

represents: a unique pointer; allows: child reads, child writes; rejects: foreign reads (Frozen), foreign writes (Disabled).

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Frozen

represents: a shared pointer; allows: all read accesses; rejects child writes (UB), foreign writes (Disabled).

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Disabled

represents: a dead pointer; allows: all foreign accesses; rejects: all child accesses (UB).

Implementations§

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impl PermissionPriv

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fn is_initial(&self) -> bool

Check if self can be the initial state of a pointer.

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fn compatible_with_protector(&self) -> bool

Reject ReservedIM that cannot exist in the presence of a protector.

Trait Implementations§

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impl Clone for PermissionPriv

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fn clone(&self) -> PermissionPriv

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for PermissionPriv

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

Formats the value using the given formatter. Read more
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impl Display for PermissionPriv

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

Formats the value using the given formatter. Read more
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impl Hash for PermissionPriv

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

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for PermissionPriv

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

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

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

PermissionPriv is ordered by the reflexive transitive closure of Reserved(conflicted=false) < Reserved(conflicted=true) < Active < Frozen < Disabled. Reserved that have incompatible ty_is_freeze are incomparable to each other. This ordering matches the reachability by transitions, as asserted by the exhaustive test permissionpriv_partialord_is_reachability.

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

Tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

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

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impl Eq for PermissionPriv

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impl StructuralPartialEq for PermissionPriv

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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:

  • ReservedFrz: 1 byte
  • ReservedIM: 0 bytes
  • Active: 0 bytes
  • Frozen: 0 bytes
  • Disabled: 0 bytes