Information Technology Reference
In-Depth Information
if
(rightAsD ==
null
)
return false
;
if
(
base
.Equals(rightAsD) ==
false
)
return false
;
return this
.Equals(rightAsD);
}
#region
IEquatable<D> Members
public bool
Equals(
D
other)
{
// elided.
return true
;
// or false, based on test
}
#endregion
}
//Test:
B
baseObject =
new
B
();
D
derivedObject =
new
D
();
// Comparison 1.
if
(baseObject.Equals(derivedObject))
Console
.WriteLine(
"Equals"
);
else
Console
.WriteLine(
"Not Equal"
);
// Comparison 2.
if
(derivedObject.Equals(baseObject))
Console
.WriteLine(
"Equals"
);
else
Console
.WriteLine(
"Not Equal"
);
Under any possible circumstances, you would expect to see either Equals
or Not Equal printed twice. Because of some errors, this is not the case
with the previous code. The second comparison will never return true.
The base object, of type B, can never be converted into a D. However, the
first comparison might evaluate to true. The derived object, of type D, can
be implicitly converted to a type B. If the B members of the right-side argu-
