🚀 go-pugleaf

In article <3EDB6B20.2000804@lgl.kos.net>,
 Edward Chew <ekc-noreply@lgl.kos.net> wrote:

>MW Ron wrote:
>> In article <3ED6734A.6080600@lgl.kos.net>,
>>  Edward Chew <ekc-noreply@lgl.kos.net> wrote:
>> 
>> 
>>>After upgrading to CW 8, I notice the compiler no longer allows implicit 
>>>casting from function pointers (e.g. "int (*)()") to void*.  Is this a 
>>>bug or some weird C/C++ standards compliance thing?  For now, it seems 
>>>happy if I write static_cast<void*>(fn).
>> 
>> 
>> This is not legal implicitly or explicitly but we allow the explicit 
>> cast because this is common for legacy code.  
>
>Interesting.  I wonder why it would be illegal, and what the legal 
>alternative would be?  I ran into this problem when weak-linking to 
>certain CFM libraries and testing to see if they are available.  In 
>Apple literature, they recommend testing the init routine like this:
>
>     if(LibraryInitFunction == kUnresolvedCFragSymbolAddress)
>         reportLibraryUnavailable();
>
>This will immediately cause a type mismatch error at compile time in 
>Codewarrior 8.  Figuring a pointer is a pointer, I rewrote this as:
>
>     if(static_cast<void*>(LibraryInitFunction) ==
>        static_cast<void*>(kUnresolvedCFragSymbolAddress)
>        )
>          reportLibraryUnavailable();
>
>This seems to work fine, but now I am told it is illegal as well.  What 
>would be the proper test in that case?

You might still get away with this in C, and relaxed pointer rules did 
you try it?  

Ron

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Ron Liechty - MWRon@metrowerks.com - http://www.metrowerks.com