BoundaryMutation.h

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#ifndef BOUNDARY_MUTATION_H
#define BOUNDARY_MUTATION_H
 
#pragma once
 
#include "Mutation.h"
#include <random>
#include <vector>
#include <cstddef>
 
namespace galib {
 
    template <typename GeneType>
    class BoundaryMutation : public Mutation<GeneType> {
    private:
        GeneType lower_m;
        GeneType upper_m;
 
    public:
        BoundaryMutation(GeneType lower, GeneType upper)
            : lower_m(lower), upper_m(upper) {}
 
        void mutate(Individual<GeneType>& individual, double mutation_rate) override {
            if (mutation_rate <= 0.0) return;
 
            thread_local static std::random_device rd;
            thread_local static std::mt19937 gen(rd());
            std::uniform_real_distribution<double> prob(0.0, 1.0);
            std::uniform_int_distribution<int> coin(0, 1);
 
            std::vector<GeneType>& genotype = individual.getGenotype();
 
            for (std::size_t i = 0; i < genotype.size(); ++i) {
                if (prob(gen) < mutation_rate) {
                    genotype[i] = (coin(gen) == 0) ? lower_m : upper_m;
                }
            }
        }
    };
 
}
 
#endif // BOUNDARY_MUTATION_H