Student with whitespace fmt

student.cpp

#include <iostream>
#include <vector>
#include <iterator>

class student_fmt;

struct student
{
    student() = default;
    student(std::string const& name, std::string const& a,
            std::string const& b,    std::string const& c)
        : m_name(name)
        , m_a(a)
        , m_b(b)
        , m_c(c)
    { }

    friend std::istream& operator>>(std::istream& is, student& s)
    {
        if (std::has_facet<student_fmt>(is.getloc()))
        {
            is >> s.m_name >> s.m_a >> s.m_b >> s.m_c;
        }
        return is;
    }

    void display() const
    {
        std::cout << m_name << m_a << " " << m_b << " " << m_c << '\n';
    }
private:
    std::string m_name, m_a, m_b, m_c;
};

class student_fmt : public std::ctype<char>
{
    static mask table[table_size];
public:
    student_fmt(size_t refs = 0) : std::ctype<char>(table, false, refs)
    {
        table[static_cast<int>(',')] |= space;
    }
};

student_fmt::mask student_fmt::table[table_size];

int main()
{
    std::cin.imbue(std::locale(std::cin.getloc(), new student_fmt));
    std::vector<student> v(std::istream_iterator<student>(std::cin), {});

    for (auto& c : v)
        c.display();
}