从另一个类的成员函数编辑私有类成员

Question

My two classes are:

class sequence
{
public:
...

private:
int number_of_samples;
float* samples;
};

class FIR
{
public:
...

sequence* apply_filter(const sequence& f);

private:
int number_of_coefficients;
float* coefficients;
};

When I run the following member function:

sequence* FIR::apply_filter(const sequence& f)
{
ofstream output_sequence_file("output.txt");
output_sequence_file<<number_of_coefficients<<endl;
sequence* Vout = new sequence;
for(int i=0;i<number_of_coefficients;i++)
{
    if (0==i) Vout->samples[i]=coefficients[i]*f.samples[i];
    else Vout->samples[i]=coefficients[i] * f.samples[i] + Vout->samples[i-1];

output_sequence_file<<Vout->samples[i]<<endl;
}
}

I get an error saying: 'samples' is a private member of sequence.

Any help? Thank you

Answer 1

Move samples into the public section of class sequence or declare FIR::apply_filter() a friend of class sequence . Private members of a class cannot be accessed by other classes or functions unless they have been granted the privilege.