__traits and determining all overridable functions

[Steven Schveighoffer]

"Christopher Wright" wrote
> http://dsource.org/projects/dmocks/browser/trunk/dmocks
> Take a look at MockObject.d and MethodMock.d -- they have pretty much 
> everything you need. Maybe I should extract them out....

Excellent work!  I think this is exactly what I was looking for.

>> However, in doing so I find that the function does not work correctly, 
>> and in addition, the argument to __traits for isVirtualFunction does not 
>> take a string, but the result of __traits allMembers is an array of 
>> strings.  I think it would be more useful if isVirtualFunction and the 
>> other isXX would take either a string or the direct statement.  For 
>> example:
>>
>> __traits(isVirtualFunction, "A.foo")
>> would be the same as:
>> __traits(isVirtualFunction, A.foo)
>
> class A {
>    final void foo ();
>    int foo (int i);
> }
>
> What to return?
> __traits(isVirtualFunction, A.foo) is ambiguous as well. I don't recommend 
> using it, and I don't use it.

Hm... good point.  So the getVirtualFunctions would be a better idea.

>
>> Then I could do:
>>
>> foreach(x; __traits(allMembers, A))
>>     if(__traits(isVirtualfunction, "A." ~ x))
>>         // append to string that redefines virtual function.
>
> You can't foreach an array at compile time, and __traits(allMembers) 
> returns an array. You can index an array at compile time, but again, you 
> can't use a while loop at compile time.
>
> You have to use recursion.

Aha!  this is what I was missing :)

>
> Eventually, static foreach should be able to do this. Or you can bug 
> Walter about changing allMembers to return a tuple of strings.
>
>> Second, the mixin doesn't work.  I hard-coded the function to output the 
>> string I was trying to build.  Therefore, the compiler should be able to 
>> execute the method in compile time, and pre-determine the string to 
>> return. But the mixin just defines the function name that I am calling as 
>> a member. i.e., I define my function above as:
>>
>> string redefFunctions(T)();
>>
>> and my mixin in the class is:
>>
>> mixin(redefFunctions!(A)());
>>
>> But when I build my class, there is a member redefFunctions!(A) instead 
>> of the list of virtual functions I expected to override.
>
> Not sure what the problem there is. If you omit the parentheses around the 
> template method call, you'll definitely get the result you describe (that 
> had me hung up for a bit), but your example has the parentheses.

Not sure either :)  But enough about my horribly disfigured abortion of 
code, I think I'll just base my stuff off of your Mock Objects lib :)

-Steve