• Ary Manzana (19/19) Mar 19 2007 The following code:
• Chris Nicholson-Sauls (9/36) Mar 19 2007 Its not technically a bug, per se, although I agree with you on what wou...
• Ary Manzana (11/47) Mar 20 2007 The strange thing is that in the semantic code you have:

Ary Manzana <ary esperanto.org.ar> writes:

The following code:

class X {
	
	public final void bla() {
	}
	
}

class Y : X {
	
	public override void bla() {
	}
	
}

gives:

main.d(10): function main.Y.bla function bla does not override any

I'd expect the error to be:

main.d(10): function main.Y.bla cannot override final function main.X.bla

(which I do get if I put the "final" keyword in bla on class Y)

Am I misunderstanding something or this is a bug?

Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:

Ary Manzana wrote:
 The following code:
 
 class X {
     
     public final void bla() {
     }
     
 }
 
 class Y : X {
     
     public override void bla() {
     }
     
 }
 
 gives:
 
 main.d(10): function main.Y.bla function bla does not override any
 
 I'd expect the error to be:
 
 main.d(10): function main.Y.bla cannot override final function main.X.bla
 
 (which I do get if I put the "final" keyword in bla on class Y)
 
 Am I misunderstanding something or this is a bug?

Its not technically a bug, per se, although I agree with you on what would have
been the 
more intuitive error message -- and perhaps that should be filed as a
suggestion.  The 
general logic behind seems to be this: 'override' usurps virtual methods, and
'final' 
makes a method non-virtual.  So for the internal checks of 'override' there is
no 
'/*(virtual)*/ void bla()' to match.

Slightly screwy, but understandable.  I would think it straightforward to add a 
last-resort check for matching 'final'/non-virtual methods.

-- Chris Nicholson-Sauls

Ary Manzana <ary esperanto.org.ar> writes:

Chris Nicholson-Sauls escribió:
 Ary Manzana wrote:
 The following code:

 class X {
         public final void bla() {
     }
     }

 class Y : X {
         public override void bla() {
     }
     }

 gives:

 main.d(10): function main.Y.bla function bla does not override any

 I'd expect the error to be:

 main.d(10): function main.Y.bla cannot override final function main.X.bla

 (which I do get if I put the "final" keyword in bla on class Y)

 Am I misunderstanding something or this is a bug?

 
 Its not technically a bug, per se, although I agree with you on what 
 would have been the more intuitive error message -- and perhaps that 
 should be filed as a suggestion.  The general logic behind seems to be 
 this: 'override' usurps virtual methods, and 'final' makes a method 
 non-virtual.  So for the internal checks of 'override' there is no 
 '/*(virtual)*/ void bla()' to match.
 
 Slightly screwy, but understandable.  I would think it straightforward 
 to add a last-resort check for matching 'final'/non-virtual methods.
 
 -- Chris Nicholson-Sauls

The strange thing is that in the semantic code you have:

if (isFinal()) {
   ...
   // other checks
   ...
   error("...cannot override final...");
   ...
}

So it seems that message would only show if the overriding function also 
has the final modifier. Strange behaviour...