???????????????????????Int32 i=r1??????????????????????????????????????????????????￡?

???????????????10.
?????????????????????????????Rational????? Int32????????explicit(?????)????????????????????Int32???????explicit????implicit(???)?????????????????????С?
?????????Rational

 

public class Rational
{
private Int32 _inner_int = 0;
public Rational()
{
}
public Rational(Int32 num)
{
this._inner_int = num;
}
public Int32 ToInt32() { return this._inner_int; }
// Implicitly constructs and returns a Rational from an Int32
public static implicit operator Rational(Int32 num)
{
return new Rational(num);
}
// Explicitly returns an Int32 from a Rational
public static <span style="color:#ff0000;">implicit</span> operator Int32(Rational r)
{
return r.ToInt32();
}
public override string ToString()
{
//return base.ToString();
String s = String.Format("{0}"?? this._inner_int);
return s;
}
}

 

???????explicit??implicit??????????????????????????
?????????Rational r1=10???????????????????????????????￡?

// Implicitly constructs and returns a Rational from an Int32
public static implicit operator Rational(Int32 num)
{
return new Rational(num);
}
?????????implicit????explicit??Rational r1=10???????(???????в???)??