Add default WinMD references to the desktop templates.

[jlaanstra]

For Universal Windows templates the xaml build targets and C++ build targets add the platform WinMDs to the reference list. However this doesn't happen for desktop templates , because the TargetPlatformIdentifier is not set to UAP.

We have two options:

• Set TargetPlatform to UAP
• Explicitly add the references.

Since these are desktop templates, option 2 seems preferable.

A possibly even better solution would be the WinRT targets to add the references. However we would have to fight the default C++ build targets to have them stop automatically adding the references and that would be quite a bit of work and possibly break xaml.

Fixes #780

[kennykerr]

Will this also fix #774 (comment)? cc @DHowett

[DHowett]

We've been told by the VC project system folks in no uncertain terms that wildcards are explicitly disallowed in vcxprojs (outside of a Target that generates them!) and they'll go out of their way to break them. This solution may conflict with that.

[jlaanstra]

I am personally not a fan of this solution either. Problem is that there is no good way to add them one by one explicitly as the folder location differs per version and the C++ targets don't add any WinMDs for non-UAP projects.

If C++/WinRT targets add a set of default WinMDs, they will conflict what the C++ targets add for UAP.
If C++/WinRT targets don't add a set of default WinMDs, desktop projects have no references.

[kennykerr]

The project system isn't exactly abounding in support for C++ developers. Much of this is making the best of some bad choices.

[jlaanstra]

Let's hold off on merging this for now. I'm gonna add a target that adds the platform winmds and then have desktop templates opt-in. That's probably a better solution.

[jlaanstra]

isn't exactly abounding in support for C++ developers. Much of this is making the best of some bad choices.

I'll try to find a good (or at least much better) choice here.

[jlaanstra]

We've been told by the VC project system folks in no uncertain terms that wildcards are explicitly disallowed in vcxprojs (outside of a Target that generates them!) and they'll go out of their way to break them. This solution may conflict with that.

Thanks for calling this out @DHowett

[jlaanstra]

Updated with a target that mimics what the xaml targets do, including keeping the support for the existing overrides. I don't think we have to document this as we already have CppWinRTOverrideSDKReferences.

[kennykerr]

Thanks!