class Digit
{
 public Digit(double d) { val = d; }
 public double val;
 // ...other members

 // User-defined conversion from Digit to double
 public static implicit operator double(Digit d)
 {
  return d.val;
 }
 // User-defined conversion from double to Digit
 public static implicit operator Digit(double d)
 {
  return new Digit(d);
 }
}

class Program
{
 static void Main(string[] args)
 {
  Digit dig = new Digit(7);
  //This call invokes the implicit "double" operator
  double num = dig;
  //This call invokes the implicit "Digit" operator
  Digit dig2 = 12;
  Console.WriteLine("num = {0} dig2 = {1}", num, dig2.val);
  Console.ReadLine();
 }
}

public static explicit operator Celsius(Fahrenheit fahr)
{
 return new Celsius((5.0f / 9.0f) * (fahr.Degrees - 32));
}

Fahrenheit fahr = new Fahrenheit(100.0f);
Console.Write($"{fahr.Degrees} Fahrenheit");
Celsius c = (Celsius)fahr;

class Celsius
{
 public Celsius(float temp)
 {
  Degrees = temp;
 }
 
 public float Degrees { get; }
 
 public static explicit operator Fahrenheit(Celsius c)
 {
  return new Fahrenheit((9.0f / 5.0f) * c.Degrees + 32);
 }
}

class Fahrenheit
{
 public Fahrenheit(float temp)
 {
  Degrees = temp;
 }
 
 public float Degrees { get; }
 
 public static explicit operator Celsius(Fahrenheit fahr)
 {
  return new Celsius((5.0f / 9.0f) * (fahr.Degrees - 32));
 }
}

class MainClass
{
 static void Main()
 {
  Fahrenheit fahr = new Fahrenheit(100.0f);
  Console.Write($"{fahr.Degrees} Fahrenheit");
  Celsius c = (Celsius)fahr;

  Console.Write($" = {c.Degrees} Celsius");
  Fahrenheit fahr2 = (Fahrenheit)c;
  Console.WriteLine($" = {fahr2.Degrees} Fahrenheit");
 }
}
// 輸出:
// 100 Fahrenheit = 37.77778 Celsius = 100 Fahrenheit

struct Digit
{
 byte value;
 public Digit(byte value)
 {
  if (value > 9)
  {
   throw new ArgumentException();
  }
  this.value = value;
 }

 // 定義從byte到Digit的顯示轉(zhuǎn)換 explicit operator:
 public static explicit operator Digit(byte b)
 {
  Digit d = new Digit(b);
  Console.WriteLine("轉(zhuǎn)換已完成");
  return d;
 }
}

class ExplicitTest
{
 static void Main()
 {
  try
  {
   byte b = 3;
   Digit d = (Digit)b; // 顯示轉(zhuǎn)換
  }
  catch (Exception e)
  {
   Console.WriteLine("{0} 捕獲到一成.", e);
  }
 }
}
/*
輸出:
轉(zhuǎn)換已完成
*/