using System;

public class Program

{

    public static void Main()

    {

        var integer = ConvertValue<int>("123");

        var doubleValue = ConvertValue<double>("123.455");

        Console.WriteLine(integer);

        Console.WriteLine(doubleValue);

    }

    public static T ConvertValue<T>(string value)

    {

        return (T)Convert.ChangeType(value, typeof(T));

    }

}