Enum TieBreak 

#[non_exhaustive]
pub enum TieBreak {
    Strict,
    Seeded,
}

How Pbt ranks a reporter against population members that reported exactly the same value at the same interval.

The default, Strict, is the historical behavior and changing it needs a D91 version decision.

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.

Strict

Only strictly better members count against the reporter, so a trial tied with the field is never an underperformer. A population that reports one shared value — a sparse reward still at zero — never exploits.

Seeded

The reporter takes a uniformly drawn position inside its tie group, so a fully tied population exploits its bottom quantile in expectation. The draw comes from a stream derived from the reporting trial’s seed and the step, separate from the parent and perturbation draws, so it is reproducible single-worker and leaves those draws unchanged.

Trait Implementations

impl Clone for TieBreak

fn clone(&self) -> TieBreak

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TieBreak

impl Debug for TieBreak

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

Formats the value using the given formatter.

impl Default for TieBreak

fn default() -> TieBreak

Returns the “default value” for a type.

impl Eq for TieBreak

impl PartialEq for TieBreak

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TieBreak