using System;
using System.Collections.Generic;

public struct Range<T>
{
    public T From { get; set; }
    public T To { get; set; }

    public bool HasValue(T value)
    {
        return value != null
        	&& (From == null || Comparer<T>.Default.Compare(From, value) <= 0)
        	&& (To == null || Comparer<T>.Default.Compare(To, value) >= 0);
    }
}

public class Test
{
	public static void Main()
	{
		var a = new Range <int> { From = 10, To = 16 };
		Console.WriteLine("var a = new Range <int> { From = 10, To = 16 };");
		Console.WriteLine(a.HasValue(0));
		Console.WriteLine(a.HasValue(15));
		Console.WriteLine(a.HasValue(17));
		Console.WriteLine();
		
		var b = new Range <int?> { From = 10, To = 16 };
		Console.WriteLine("var b = new Range <int?> { From = 10, To = 16 };");
		Console.WriteLine(b.HasValue(null));
		Console.WriteLine(b.HasValue(0));
		Console.WriteLine(b.HasValue(15));
		Console.WriteLine(b.HasValue(17));
		Console.WriteLine();
		
		var c = new Range <int?> { From = null, To = 16 };
		Console.WriteLine("var c = new Range <int?> { From = null, To = 16 };");
		Console.WriteLine(c.HasValue(null));
		Console.WriteLine(c.HasValue(0));
		Console.WriteLine(c.HasValue(15));
		Console.WriteLine(c.HasValue(17));
		Console.WriteLine();
		
		var d = new Range <int?> { From = 10, To = null };
		Console.WriteLine("var d = new Range <int?> { From = 10, To = null };");
		Console.WriteLine(d.HasValue(null));
		Console.WriteLine(d.HasValue(0));
		Console.WriteLine(d.HasValue(15));
		Console.WriteLine(d.HasValue(17));
		Console.WriteLine();
		
		var e = new Range <int?> { From = null, To = null };
		Console.WriteLine("var e = new Range <int?> { From = null, To = null };");
		Console.WriteLine(e.HasValue(null));
		Console.WriteLine(e.HasValue(0));
		Console.WriteLine(e.HasValue(15));
		Console.WriteLine(e.HasValue(17));
		Console.WriteLine();
	}
}