#include <charconv>
#include <iomanip>
#include <iostream>
#include <limits>
#include <string>

using namespace std;

long double GetLongDouble() {
    string str;
    long double result;
    bool is_converted = false;

    do
    {
        getline(cin, str);
        auto [ptr, ec] = std::from_chars(str.data(), str.data() + str.size(), result);

        if (ec == std::errc())
        {
            return result;
        }
        else if (ec == std::errc::invalid_argument)
        {
            std::cout << "This is not a number.\n";
        }
        else if (ec == std::errc::result_out_of_range)
        {
            std::cout << "This number is larger than an long double.\n";
        }

        std::cin.clear();                                                        // reset the fail flags
        std::cin.ignore(std::numeric_limits< std::streamsize >::max(), '\n');    // ignore the bad input until line end
        cout << "Please enter value again\n";
    } while (true);

    /*
    do
    {
        try
        {
            getline(cin, long_double);

            //https://en.cppreference.com/w/cpp/string/basic_string/stof
            result = stold(long_double);
            std::cin.clear();                                                        // reset the fail flags
            std::cin.ignore(std::numeric_limits< std::streamsize >::max(), '\n');    // ignore the bad input until line
                                                                                     // end
            return result;

        } catch (invalid_argument const &ex)
        {
            cout << "Invalid argument.\n";
        } catch (out_of_range const &ex)
        {
            cout << "Argument value is out of range\n";
        }
        cout << "Please enter value again\n";
        std::cin.clear();                                                          // reset the fail flags
        std::cin.ignore(std::numeric_limits< std::streamsize >::max(), '\n');      // ignore the bad input until line end
    } while (true);
    */
}