Enum FieldPresence 

pub enum FieldPresence {
    Present(Value),
    Missing,
}

FieldPresence

Result of attempting to read a field from a row during predicate evaluation. This distinguishes between a missing field and a present field whose value may be None.

Variants

Present(Value)

Field exists and has a value (including Value::None).

Missing

Field is not present on the row.

Trait Implementations

impl Clone for FieldPresence

fn clone(&self) -> FieldPresence

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldPresence

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

Formats the value using the given formatter.

impl PartialEq for FieldPresence

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for FieldPresence

impl StructuralPartialEq for FieldPresence