Enum ValueMissingReason 

#[non_exhaustive]
pub enum ValueMissingReason {
    UnsetScalar,
    UnsetCollection,
    EmptyCollection,
    Conversion,
}

Identifies why a read could not produce a concrete value.

The reason is independent of the source and target types. Inspect the accompanying crate::ValueMissing accessors for those types and for a collection index when one is available.

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.

UnsetScalar

Scalar storage is unset with a declared type.

UnsetCollection

Collection storage is unset with a declared element type.

EmptyCollection

A concrete collection has no first item.

Conversion

Conversion policy classified a concrete scalar or collection item as missing.

Trait Implementations

impl Clone for ValueMissingReason

fn clone(&self) -> ValueMissingReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ValueMissingReason

impl Debug for ValueMissingReason

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

Formats the value using the given formatter.

impl Eq for ValueMissingReason

impl Hash for ValueMissingReason

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ValueMissingReason

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ValueMissingReason