overload == (and != , of course) operator, can I bypass == to determine whether the object is null
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by LLS
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Published on 2010-06-09T12:38:38Z
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2010/06/09
12:42 UTC
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c#
|operator-overloading
Hello, when I try to overload operator == and != in C#, and override Equal as recommended, I found I have no way to distinguish a normal object and null. For example, I defined a class Complex.
public static bool operator ==(Complex lhs, Complex rhs)
{
return lhs.Equals(rhs);
}
public static bool operator !=(Complex lhs, Complex rhs)
{
return !lhs.Equals(rhs);
}
public override bool Equals(object obj)
{
if (obj is Complex)
{
return (((Complex)obj).Real == this.Real &&
((Complex)obj).Imaginary == this.Imaginary);
}
else
{
return false;
}
}
But when I want to use
if (temp == null)
When temp is really null, some exception happens. And I can't use == to determine whether the lhs is null, which will cause infinite loop.
What should I do in this situation.
One way I can think of is to us some thing like Class.Equal(object, object) (if it exists) to bypass the == when I do the check.
What is the normal way to solve the problem?
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