Enum PathAccessError 

#[non_exhaustive]
pub enum PathAccessError {
    RootShapeMismatch {
        expected: &'static Shape,
        actual: &'static Shape,
    },
    WrongStepKind {
        step: PathStep,
        step_index: usize,
        shape: &'static Shape,
    },
    IndexOutOfBounds {
        step: PathStep,
        step_index: usize,
        shape: &'static Shape,
        index: usize,
        bound: usize,
    },
    VariantMismatch {
        step_index: usize,
        shape: &'static Shape,
        expected_variant: usize,
        actual_variant: usize,
    },
    MissingTarget {
        step: PathStep,
        step_index: usize,
        shape: &'static Shape,
    },
    OptionIsNone {
        step_index: usize,
        shape: &'static Shape,
    },
}

Error returned when navigating a value using a Path.

Each variant captures enough context for a caller to produce a meaningful diagnostic without re-walking the path.

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.

RootShapeMismatch

The root shape of the path doesn’t match the value being navigated.

Fields

expected: &'static Shape

The shape recorded in the path.

actual: &'static Shape

The shape of the value we tried to navigate.

WrongStepKind

The step kind doesn’t apply to the current shape.

For example, PathStep::Field on a scalar, or PathStep::Index on a struct.

Fields

step: PathStep

The step that didn’t apply.

step_index: usize

Index of this step in the path (0-based).

shape: &'static Shape

The shape at the point where the step was attempted.

IndexOutOfBounds

A field or list index is out of bounds.

Fields

step: PathStep

The step that contained the out-of-bounds index.

step_index: usize

Index of this step in the path (0-based).

shape: &'static Shape

The shape of the container.

index: usize

The index that was requested.

bound: usize

The number of available items (fields, elements, variants, etc.).

VariantMismatch

The path says we should be at variant X, but the live value is variant Y.

Fields

step_index: usize

Index of this step in the path (0-based).

shape: &'static Shape

The enum shape.

expected_variant: usize

The variant index the path expected.

actual_variant: usize

The variant index found at runtime.

MissingTarget

A Deref, Inner, or Proxy step has no target.

This can happen when a smart pointer has no borrow_fn, or the shape has no inner, or no proxy definition.

Fields

step: PathStep

The step that required a target.

step_index: usize

Index of this step in the path (0-based).

shape: &'static Shape

The shape that was expected to provide a target.

OptionIsNone

An OptionSome step was encountered but the value is None.

Fields

step_index: usize

Index of this step in the path (0-based).

shape: &'static Shape

The option shape.

Trait Implementations

impl Clone for PathAccessError

fn clone(&self) -> PathAccessError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PathAccessError

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

Formats the value using the given formatter.

impl Display for PathAccessError

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

Formats the value using the given formatter.

impl Error for PathAccessError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.