何が問題なのですか :
/(?<={).+(?=public)/s
全文
class WeightConvertor {
private:
    double gram;
    double Kilogram;
    double Tonnes;
    void SetGram(double);
    void SetKiloGram(double);
    void SetTonnes(double);
matching end
public:
    WeightConvertor();
    WeightConvertor(double, double, double);
    ~WeightConvertor();
    void SetWeight(double, double, double);
    void GetWeight(double&, double& ,double&);
    void PrintWeight();
    double TotalWeightInGram();
public:
};
このテキストだけを一致させるにはどうすればよいですか :
private:
    double gram;
    double Kilogram;
    double Tonnes;
    void SetGram(double);
    void SetKiloGram(double);
    void SetTonnes(double);
matching end