Enum ValueMissing 

#[non_exhaustive]
pub enum ValueMissing {
    UnsetScalar {
        data_type: DataType,
    },
    UnsetCollection {
        data_type: DataType,
    },
    EmptyCollection {
        data_type: DataType,
    },
    EmptyCollectionConversion {
        to: DataType,
    },
    Conversion {
        from: DataType,
        to: DataType,
    },
    CollectionItem {
        source_index: usize,
        from: DataType,
        to: DataType,
    },
}

Describes the typed state that produced a missing-value error.

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

A scalar was unset with a declared data type.

Fields

data_type: DataType

Type retained by the unset scalar storage.

UnsetCollection

A collection was unset with a declared element type.

Fields

data_type: DataType

Element type retained by the unset collection storage.

EmptyCollection

A concrete collection contains no item for a first-item read.

Fields

data_type: DataType

Element type of the concrete empty collection.

EmptyCollectionConversion

A conversion requested one item from an empty collection.

The source collection has no item and therefore no source value type can be recovered from the shared conversion error. to records the requested target type instead of overloading EmptyCollection.

Fields

to: DataType

Requested target data type.

Conversion

A conversion policy treated a concrete scalar as missing.

Fields

from: DataType

Declared source data type.

to: DataType

Requested target data type.

CollectionItem

A collection item conversion produced no value.

Fields

source_index: usize

Original zero-based source position.

from: DataType

Declared source data type.

to: DataType

Requested target data type.

Implementations

impl ValueMissing

pub const fn source_type(self) -> Option<DataType>

Returns the source or declared data type associated with the error.

Returns None for Self::EmptyCollectionConversion because no source item exists for that conversion.

pub const fn target_type(self) -> Option<DataType>

Returns the requested target type for conversion failures.

pub const fn source_index(self) -> Option<usize>

Returns the source index for a missing collection item.

pub const fn is_unset(self) -> bool

Reports whether storage itself is unset.

pub const fn is_empty_collection(self) -> bool

Reports whether a concrete collection is empty.

pub const fn is_conversion(self) -> bool

Reports whether the missing value came from a conversion.

Trait Implementations

impl Clone for ValueMissing

fn clone(&self) -> ValueMissing

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ValueMissing

impl Debug for ValueMissing

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

Formats the value using the given formatter.

impl Display for ValueMissing

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

Formats the value using the given formatter.

impl Eq for ValueMissing

impl Hash for ValueMissing

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 ValueMissing

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ValueMissing