Re: Why has base class protection been deprecated?
On Tuesday, 24 April 2012 at 12:22:14 UTC, David Bryant wrote: This bothers me for two reasons: firstly it's not a base class, and secondly, it's a standard OO pattern of mine. What's up with this? Generally (and slightly inaccurately) speaking, D follows the Java model for inheritance rather than the C++ one, where base class protection attributes simply do not exist. Besides that, I'm not quite sure what privately inheriting an interface would buy you – there would be no implementation to inherit anyway (except for final interface methods, but I doubt a valid use case for this would be easy to find)? David
Re: Why has base class protection been deprecated?
On 04/24/2012 11:47 PM, David Bryant wrote: On 04/24/2012 11:07 PM, Don Clugston wrote: On 24/04/12 15:29, David Bryant wrote: Because it doesn't make sense. All classes are derived from Object. That _has_ to be public, otherwise things like == wouldn't work. Does the same apply for interfaces? I'm specifically implementing an interface with non-public visibility. This shouldn't affect the visibility of the implicit Object base-class. Right. Only classes are affected. Ok...so I still don't understand why the original example shouldn't compile. I'm not trying to change the visibility of the base class but rather the visibility of the interface. To be clear: my subject line is misleading. I used that text because it's what came out of the compiler's mouth. I do understand your reasoning why you can't change the visibility of a base class, just not for an interface.
Re: Why has base class protection been deprecated?
On 04/24/2012 11:07 PM, Don Clugston wrote: On 24/04/12 15:29, David Bryant wrote: Because it doesn't make sense. All classes are derived from Object. That _has_ to be public, otherwise things like == wouldn't work. Does the same apply for interfaces? I'm specifically implementing an interface with non-public visibility. This shouldn't affect the visibility of the implicit Object base-class. Right. Only classes are affected. Ok...so I still don't understand why the original example shouldn't compile. I'm not trying to change the visibility of the base class but rather the visibility of the interface.
Re: Why has base class protection been deprecated?
On 24/04/12 15:29, David Bryant wrote: Because it doesn't make sense. All classes are derived from Object. That _has_ to be public, otherwise things like == wouldn't work. Does the same apply for interfaces? I'm specifically implementing an interface with non-public visibility. This shouldn't affect the visibility of the implicit Object base-class. Right. Only classes are affected.
Re: Why has base class protection been deprecated?
Because it doesn't make sense. All classes are derived from Object. That _has_ to be public, otherwise things like == wouldn't work. Does the same apply for interfaces? I'm specifically implementing an interface with non-public visibility. This shouldn't affect the visibility of the implicit Object base-class.
Re: Why has base class protection been deprecated?
On 24/04/12 14:22, David Bryant wrote:
With the dmd 2.059 I have started getting the error 'use of base class
protection is deprecated' when I try to implement an interface with
private visibility, ie:
interface Interface { }
class Class : private Interface { }
$ dmd test.d
test.d(4): use of base class protection is deprecated
This bothers me for two reasons: firstly it's not a base class, and
secondly, it's a standard OO pattern of mine.
What's up with this?
Thanks,
Dave
Because it doesn't make sense. All classes are derived from Object. That
_has_ to be public, otherwise things like == wouldn't work.
Previously, the compiler used to allow base class protection, but it
ignored it.
