#include <string>

// .h

class AlmaPrivate;

class Alma {

public:
    void aaa();
    void bbb(const std::string &s);
    void bbb(int i);

private:
    AlmaPrivate *d;

};

// .cpp

class AlmaPrivate {

private:
    friend class Alma;

    std::string s1;
    std::string s2;
    int i2;
};

void Alma::aaa() {}

void Alma::bbb(const std::string &s) {
    d->s1 = s;
}

void Alma::bbb(int i) {
    d->i2 = i;
}