[HarfBuzz] 'CoverageFormat1::Iter' cannot access private struct declared in class 'CoverageFormat1'

[Jonathan Kew]

On 16/9/12 02:15, Behdad Esfahbod wrote:
> On 09/13/2012 07:32 AM, Samiullah Khawaja wrote:
>> Hi,
>>
>> I am trying to build hurfbuzz 0.9.3 in Visual Studio 2005. It gives me
>> following error in file: hb-ot-layout-common-private.h on line: 561
>>
>> 'CoverageFormat1::Iter' cannot access private struct declared in class
>> 'CoverageFormat1'.
>>
>> I did some investigation and found that the Iter is declared private in the
>> CoverageFormat1 struct and thus the compiler error occurs.
>
> Humm.  This sounds like a difference in how "friend" handling works in VS
> 2005.  I'm leaning towards not having to support such an old compiler.  I
> tried adding additional friend declarations to help resolve this but adding
> "friend Coverage::Iter" before Coverage itself is fully defined doesn't seem
> to work, so I'm out of ideas for a simple fix short of making the Iter's
> public.  That's probably not a big deal, but diverts from the current design
> of HarfBuzz.

If you're willing to clutter the code a bit for the sake of 
compatibility, you could do something like

#if defined(_MSC_VER) && (_MSC_VER < 1500) /* pre-2008 visual studio */
#define HB_PRIVATE_UNLESS_OLD_MSVC public
#else
#define HB_PRIVATE_UNLESS_OLD_MSVC private
#endif

and then mark the relevant Iter declarations with 
"HB_PRIVATE_UNLESS_OLD_MSVC:".

That would avoid making the Iter public for other builds, so that modern 
compilers will still be checking that nobody else tries to use it.

JK