Enum BackendPolicy 

#[non_exhaustive]
pub enum BackendPolicy {
    ScalarExecutionOnly,
    SimdFeatureDisabled,
    NoDetectedSimdCandidate,
    HighAssuranceScalarOnly,
}

Deployment policy for runtime backend assertions.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

ScalarExecutionOnly

Require encode/decode execution to remain on a terminal scalar backend.

NeverRun and Testing health states do not satisfy this policy: their temporary scalar fallback may later transition to acceleration.

SimdFeatureDisabled

Require the crate to be built without the simd feature.

NoDetectedSimdCandidate

Require no SIMD candidate to be visible to this build and target.

HighAssuranceScalarOnly

Require scalar execution, the simd feature disabled, no detected SIMD candidate, the unsafe boundary enforced, and a CT result gate classified as a native hardware speculation barrier.

This policy intentionally rejects targets that report only an unattested hardware barrier, ordering fence, or compiler fence for the CT result gate. On AArch64, the crate emits isb sy plus the CSDB hint but reports that posture as unattested; deployments that rely on CSDB must carry platform evidence outside this built-in policy check.

Implementations

impl BackendPolicy

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

Returns the stable lowercase identifier for this policy.

assert_eq!(
    base64_ng::runtime::BackendPolicy::HighAssuranceScalarOnly.as_str(),
    "high-assurance-scalar-only",
);

Trait Implementations

impl Clone for BackendPolicy

fn clone(&self) -> BackendPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BackendPolicy

impl Debug for BackendPolicy

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

Formats the value using the given formatter.

impl Display for BackendPolicy

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

Formats the value using the given formatter.

impl Eq for BackendPolicy

impl PartialEq for BackendPolicy

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for BackendPolicy