Enum Refusal 

pub enum Refusal {
    Integer,
    NotFloat,
    NoF64,
    Unsupported(&'static str),
    Declined,
    TooSmall,
    Failed(String),
}

Why a fused node ran on the CPU although a device was asked for.

Every one of these is a statement about the kernel or its data, decided before any work happens, except Failed, which is the device itself refusing at run time. A fallback is always correct and only ever slower.

Variants

Integer

The kernel’s working type is i64. WGSL has no 64-bit integer arithmetic on most adapters, so integer chains stay on the CPU.

NotFloat

The chain’s result is not f64 — a comparison at the root, a tally. Narrowing a device result is not worth the risk this phase.

NoF64

The adapter has no f64 in shaders and the caller did not ask for f32. See the module note on precision.

Unsupported(&'static str)

The generator does not cover one of the chain’s operations at this precision.

Declined

The kernel itself would decline these inputs, device or no device.

TooSmall

Too little data to pay for a dispatch.

Failed(String)

The device refused: an allocation, a shader, a queue submission.

Implementations

impl Refusal

pub fn reason(&self) -> String

Trait Implementations

impl Clone for Refusal

fn clone(&self) -> Refusal

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Refusal

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

Formats the value using the given formatter.

impl Eq for Refusal

impl PartialEq for Refusal

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Refusal