std::va_list args;

va_start(args, format);

FMT_VSNPRINTF(buffer, SIZE, format, args);

va_end(args);

private:

std::basic_string<Char> value_;

static const Char empty[];

public:

explicit basic_test_string(const Char* value = empty) : value_(value) {}

auto value() const -> const std::basic_string<Char>& { return value_; }

int year_, month_, day_;

public:

date(int year, int month, int day) : year_(year), month_(month), day_(day) {}

auto year() const -> int { return year_; }

auto month() const -> int { return month_; }

auto day() const -> int { return day_; }