//! Genetic operators and combinators.
//!
//! - [`selection`] — operators that select individuals from the population
//! - [`crossover`] — operators that recombine genomes
//! - [`mutation`] — operators that introduce random changes
//! - [`combinator`] — composable wrappers that structure operator flow
//! - [`identity`] — no-op pass-through operator
//! - [`with_rate`] — probabilistic operator wrapper
/// Identity (no-op) operator.