Enum ReplacementStrategy 

pub enum ReplacementStrategy {
    ReplaceWorst,
    ReplaceRandom,
    ReplaceParent,
    ReplaceIfBetter,
    TournamentWorst(usize),
}

Replacement strategy for steady-state GA.

EV-42: only ReplacementStrategy::ReplaceIfBetter is elitist (it accepts an offspring only when it improves on the individual it would replace). Every other strategy performs its replacement unconditionally, matching its documented meaning — in particular ReplaceRandom is a genuine, diversity- preserving stochastic replacement and may accept a worse offspring.

Variants

ReplaceWorst

Replace the worst individual in the population, unconditionally. Because the current best is never the replacement target, the population best is preserved, but the population mean may temporarily worsen.

ReplaceRandom

Replace a uniformly-random individual, unconditionally (non-elitist). A worse offspring can enter the population, preserving exploratory diversity.

ReplaceParent

Replace the worse parent, but only if the offspring beats it (generational replacement).

ReplaceIfBetter

Replace the worst individual, but only if the offspring is strictly better than it (the fully elitist, accept-if-better option).

TournamentWorst(usize)

Use an inverse tournament to choose a (likely poor) individual to replace, then replace it unconditionally.

Trait Implementations

impl Clone for ReplacementStrategy

fn clone(&self) -> ReplacementStrategy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ReplacementStrategy

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

Formats the value using the given formatter.

impl Default for ReplacementStrategy

fn default() -> ReplacementStrategy

Returns the “default value” for a type.