Enum MissingFieldsStrategy 

#[non_exhaustive]
pub enum MissingFieldsStrategy {
    Reject,
    Ecma,
}

How to infer missing fields when the fields that are present do not fully constitute a Date.

In order for the fields to fully constitute a Date, they must identify a year, a month, and a day. The fields era, era_year, and extended_year identify the year:

Era?	Era Year?	Extended Year?	Outcome
-	-	-	Error
Some	-	-	Error
-	Some	-	Error
-	-	Some	OK
Some	Some	-	OK
Some	-	Some	Error (era requires era year)
-	Some	Some	Error (era year requires era)
Some	Some	Some	OK (but error if inconsistent)

The fields month_code and ordinal_month identify the month:

Month Code?	Ordinal Month?	Outcome
-	-	Error
Some	-	OK
-	Some	OK
Some	Some	OK (but error if inconsistent)

The field day identifies the day.

If the fields identify a year, a month, and a day, then there are no missing fields, so the strategy chosen here has no effect (fields that are out-of-bounds or inconsistent are handled by other errors).

🚧 This code is considered unstable; it may change at any time, in breaking or non-breaking ways, including in SemVer minor releases. Do not use this type unless you are prepared for things to occasionally break.

Graduation tracking issue: issue #7161.

✨ Enabled with the unstable Cargo feature.

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.

Reject

If the fields that are present do not fully constitute a Date, return DateFromFieldsError::NotEnoughFields.

Ecma

If the fields that are present do not fully constitute a Date, follow the ECMAScript specification when possible.

⚠️ This option causes a year or day to be implicitly added to the Date!

This strategy makes the following changes:

1. If the fields identify a year and a month, but not a day, then set day to 1.
2. If month_code and day are set but nothing else, then set the year to a reference year: some year in the calendar that contains the specified month and day, according to the ECMAScript specification.

Note that the reference year is not added if an ordinal month is present, since the identity of an ordinal month changes from year to year.

Trait Implementations

impl Clone for MissingFieldsStrategy

fn clone(&self) -> MissingFieldsStrategy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MissingFieldsStrategy

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

Formats the value using the given formatter.

impl Default for MissingFieldsStrategy

fn default() -> MissingFieldsStrategy

Returns the “default value” for a type.

impl PartialEq for MissingFieldsStrategy

fn eq(&self, other: &MissingFieldsStrategy) -> 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 Copy for MissingFieldsStrategy

impl StructuralPartialEq for MissingFieldsStrategy