[PATCH 4/5] d2d1: Add the ID2D1Bitmap interface.

[Nikolay Sivov]

On 5/14/2014 12:05, Henri Verbeet wrote:
> On 14 May 2014 08:26, Nikolay Sivov <bunglehead at gmail.com> wrote:
>> I don't think it makes sense to match msdn here regarding [optional]
>> attribute, and that's why:
>>
>> - 'optional' without 'defaultvalue' has no effect on headers, as far as I
>> can see;
>> - you can't mix 'optional' with required arguments like that, midl will
>> refuse to process such idl,
>>    optional arguments should be at the end of arguments list only;
> I didn't try processing this with midl myself, but are you quite sure
> about that?
Yes, I tested that some time ago, and double-checked just now. Method 
like this:

---
   HRESULT method([in, optional] float arg, [in] float arg2);
---

produces midl error 2090:

.\test_tlb.idl(44) : error MIDL2090 : optional parameters must come 
after required parameters : [ Procedure 'method' ( Interface 'Iiface' ) ]


>   The d2d1.h in the PSDK has these annotated with
> "_In_opt_", and presumably it's generated with midl.
These are manually added I believe, it's a part of so called annotation 
language or SAL (http://msdn.microsoft.com/en-us/library/ms182032.aspx). 
It's kind of markers for static analysers, this page says it's available 
starting VS 2005.