contexts

using System;

namespace CSharpAdventures
{

	class MainClass
	{
		public static void Main (string[] args)
		{
			int max = Int32.MaxValue;
			//[1]
			Console.WriteLine (CheckedSum(UncheckedSum(max,1),1)); //Doesn't Break.
			//Console.WriteLine (UncheckedSum(CheckedSum(max,1),1)); //Will Break!

			//[2]
			checked {
				Console.WriteLine(Unchecked (() => max + 1));
			}
		}

		static int CheckedSum(int a, int b)
		{
			//We can nest the safe/unsafe contexts.
			checked {
				unchecked {
					//We could the keyword as an expression as well.
					int temp = unchecked(a + b);
					checked {
						return a + b;
					}
				}
			}
		}

		static int UncheckedSum(int a, int b)
		{
			unchecked {
				checked {
					int temp = checked(int.MaxValue + 0);
					unchecked {
						return a + b;
					}
				}
			}
		}


		static int Unchecked (Func<int> code) {
				return code.Invoke ();
		}
	}
}