Struct subtle::Choice[−][src]

pub struct Choice(_);

The Choice struct represents a choice for use in conditional assignment.

It is a wrapper around a u8, which should have the value either 1 (true) or 0 (false).

The conversion from u8 to Choice passes the value through an optimization barrier, as a best-effort attempt to prevent the compiler from inferring that the Choice value is a boolean. This strategy is based on Tim Maclean’s work on rust-timing-shield, which attempts to provide a more comprehensive approach for preventing software side-channels in Rust code.

The Choice struct implements operators for AND, OR, XOR, and NOT, to allow combining Choice values. These operations do not short-circuit.

Implementations

`impl Choice`[src]

`pub fn unwrap_u8(&self) -> u8`[src]

Unwrap the Choice wrapper to reveal the underlying u8.

Note

This function only exists as an escape hatch for the rare case where it’s not possible to use one of the subtle-provided trait impls.

To convert a Choice to a bool, use the From implementation instead.

Trait Implementations

`impl BitAnd<Choice> for Choice`[src]

`type Output = Choice`

The resulting type after applying the & operator.

`fn bitand(self, rhs: Choice) -> Choice`[src]

`impl BitAndAssign<Choice> for Choice`[src]

`fn bitand_assign(&mut self, rhs: Choice)`[src]

`impl BitOr<Choice> for Choice`[src]

`type Output = Choice`

The resulting type after applying the | operator.

`fn bitor(self, rhs: Choice) -> Choice`[src]

`impl BitOrAssign<Choice> for Choice`[src]

`fn bitor_assign(&mut self, rhs: Choice)`[src]

`impl BitXor<Choice> for Choice`[src]

`type Output = Choice`

The resulting type after applying the ^ operator.

`fn bitxor(self, rhs: Choice) -> Choice`[src]

`impl BitXorAssign<Choice> for Choice`[src]

`fn bitxor_assign(&mut self, rhs: Choice)`[src]

`impl Clone for Choice`[src]

`fn clone(&self) -> Choice`[src]

`pub fn clone_from(&mut self, source: &Self)`1.0.0[src]

`impl ConditionallySelectable for Choice`[src]

`fn conditional_select(a: &Self, b: &Self, choice: Choice) -> Self`[src]

`fn conditional_assign(&mut self, other: &Self, choice: Choice)`[src]

`fn conditional_swap(a: &mut Self, b: &mut Self, choice: Choice)`[src]

`impl ConstantTimeEq for Choice`[src]

`fn ct_eq(&self, rhs: &Choice) -> Choice`[src]

`impl Copy for Choice`[src]

`impl Debug for Choice`[src]

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

`impl From<u8> for Choice`[src]

`fn from(input: u8) -> Choice`[src]

`impl Not for Choice`[src]

`type Output = Choice`

The resulting type after applying the ! operator.

`fn not(self) -> Choice`[src]

Auto Trait Implementations

`impl RefUnwindSafe for Choice`

`impl Send for Choice`

`impl Sync for Choice`

`impl Unpin for Choice`

`impl UnwindSafe for Choice`

Blanket Implementations

`impl<T> Any for T where T: 'static + ?Sized,` [src]

`pub fn type_id(&self) -> TypeId`[src]

`impl<T> Borrow<T> for T where T: ?Sized,` [src]

`pub fn borrow(&self) -> &T`[src]

`impl<T> BorrowMut<T> for T where T: ?Sized,` [src]

`pub fn borrow_mut(&mut self) -> &mut T`[src]

`impl<T> From<T> for T`[src]

`pub fn from(t: T) -> T`[src]

`impl<T, U> Into<U> for T where U: From<T>,` [src]

`pub fn into(self) -> U`[src]

`impl<T> ToOwned for T where T: Clone,` [src]

`type Owned = T`

The resulting type after obtaining ownership.

`pub fn to_owned(&self) -> T`[src]

`pub fn clone_into(&self, target: &mut T)`[src]

`impl<T, U> TryFrom<U> for T where U: Into<T>,` [src]

`type Error = Infallible`

The type returned in the event of a conversion error.

`pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

`impl<T, U> TryInto<U> for T where U: TryFrom<T>,` [src]

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

The type returned in the event of a conversion error.

`pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]