[cfe-dev] Proposed change to __builtin_overload

[Chris Lattner]

On Feb 9, 2009, at 8:33 AM, Douglas Gregor wrote:
>>
>
> It would take a bit of work to support such a pragma in Clang,  
> because we currently have quite a few places where we make a lot of  
> assumptions about language-specific data structures based on the  
> current language we're parsing (e.g., we assume that all class types  
> are handled by CXXRecordDecl in C++ mode). However, it seems  
> reasonable that we would work toward making Clang #pragma c++'able.
>
> In the shorter term, I think some kind of __overload__ attribute  
> would be relatively easy to implement. Most of the pain would be in  
> making sure that the C++ implicit-conversion rules handle all of the  
> funky C99 types :)

I spoke with Doug more about this offline, and I agree.  We should add  
an __attribute__((overloadable)) or something like that.  Doug  
volunteered to tackle this when he gets to a good intermediate point  
on his template work.  I filed PR 3542 to track this.

Thanks Doug!  When this is done, I'll do the horrible header hacking  
stuff to hook it up for tgmath.h to use.

-Chris