Struct FrictionGate 

pub struct FrictionGate<D: Gateable> { /* private fields */ }

Compile-time-checked friction wrapper. Construct via FrictionGate::new, which accepts only Increases-typed commands; the function signature prevents callers from accidentally friction-wrapping a risk-reducing action.

Risk-asymmetry invariant (compile-time)

The point of the type parameter is to make this line unable to compile:

use zero_commands::risk::FrictionGate;

// A local `Reduces` phantom. Not `Gateable` — there is no
// way for an external crate to make it `Gateable`, because
// `Gateable` is sealed to this crate (see `sealed` module).
#[derive(Clone, Copy)]
struct Reduces;

// This must be a compile error, not a runtime one. If it
// compiles, the type-level guarantee is gone and a
// risk-reducing command could be wrapped in friction.
let _: FrictionGate<Reduces> = FrictionGate::new();

The control is also positive: a FrictionGate<Increases> is constructible and reports its direction honestly.

use zero_commands::risk::{FrictionGate, Increases, RiskDirection};
let g = FrictionGate::<Increases>::new();
assert_eq!(g.direction(), RiskDirection::Increases);

Implementations

impl FrictionGate<Increases>

pub const fn new() -> Self

pub const fn direction(&self) -> RiskDirection

The direction this gate operates on. Useful for logging when a friction pause is shown to the operator.

Trait Implementations

impl<D: Clone + Gateable> Clone for FrictionGate<D>

fn clone(&self) -> FrictionGate<D>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<D: Debug + Gateable> Debug for FrictionGate<D>

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

Formats the value using the given formatter.

impl Default for FrictionGate<Increases>

fn default() -> Self

Returns the “default value” for a type.

impl<D: Copy + Gateable> Copy for FrictionGate<D>