Hello,
Could you please fill a bug report.
Thanks
Marek
Except that Y is constrained to be of type Z and so is guaranteed to
be a reference type.
On Mon, Nov 15, 2010 at 12:30 AM, Bojan Rajkovic
<severedcr...@gmail.com <mailto:severedcr...@gmail.com>> wrote:
On Nov 14, 2010, at 10:16 PM, Tom Philpot wrote:
The following code compiled with a warning on Mono 2.7 (as of
147679) but has an error in 2.8.
namespace Application
{
public class Z {}
public class A<X, Y>
where Y : Z
where X : Y
{
protected void SomeOperation(Y y)
{
X x = y as X;
}
}
public class Foo { public static void Main() {} }
}
/opt/mono-2.8/bin/gmcs CS0413Regression.cs
CS0413Regression.cs(12,33): error CS0413: The `as' operator
cannot be used with a non-reference type parameter `X'. Consider
adding `class' or a reference type constraint
Compilation failed: 1 error(s), 0 warnings
/opt/mono-r147679/bin/gmcs CS0413Regression.cs
CS0413Regression.cs(12,27): warning CS0219: The variable `x' is
assigned but its value is never used
Compilation succeeded - 1 warning(s)
The error message here is the correct thing to do—as casts are
only valid with reference types, because they can result in null,
which is invalid for a value type. If this raised only a warning
in gmcs earlier, it was a bug.
—Bojan
_______________________________________________
Mono-devel-list mailing list
Mono-devel-list@lists.ximian.com
<mailto:Mono-devel-list@lists.ximian.com>
http://lists.ximian.com/mailman/listinfo/mono-devel-list
_______________________________________________
Mono-devel-list mailing list
Mono-devel-list@lists.ximian.com
<mailto:Mono-devel-list@lists.ximian.com>
http://lists.ximian.com/mailman/listinfo/mono-devel-list
_______________________________________________
Mono-devel-list mailing list
Mono-devel-list@lists.ximian.com
http://lists.ximian.com/mailman/listinfo/mono-devel-list
_______________________________________________
Mono-devel-list mailing list
Mono-devel-list@lists.ximian.com
http://lists.ximian.com/mailman/listinfo/mono-devel-list
