Windows 10 SDK is now available for Preview Build 17040.

The Preview SDK can be downloaded from developer section on Windows Insider.

Things to note:

  • This build works in conjunction with previously released SDKs and Visual Studio 2017. You can install this SDK and still also continue to submit your apps that target Windows 10 Creators build or earlier to the store.
  • The Windows SDK will now formally only be supported by Visual Studio 2017 and greater. You can download the Visual Studio 2017 here.

Known Issues

  • “All tests run with Windows App Certification Kit will fail.  During installation, please uncheck Windows App Certification Kit”

What’s New:

  • C++/WinRT Now Available:
    The C++/WinRT headers and cppwinrt compiler (cppwinrt.exe) are now included in the Windows SDK. The compiler comes in handy if you need to consume a third-party WinRT component or if you need to author your own WinRT components with C++/WinRT. The easiest way to get working with it after installing the Windows Insider Preview SDK is to start the Visual Studio Developer Command Prompt and run the compiler in that environment. Authoring support is currently experimental and subject to change. Stay tuned as we will publish more detailed instructions on how to use the compiler in the coming week.The ModernCPP blog has a deeper dive into the CppWinRT compiler. Please give us feedback by creating an issue at: https://github.com/microsoft/cppwinrt.

Breaking Changes

New MIDL key words. 

As a part of the “modernizing IDL” effort, several new keywords are added to the midlrt tool. These new keywords will cause build breaks if they are encountered in IDL files.

The new keywords are:

  • event
  • set
  • get
  • partial
  • unsealed
  • overridable
  • protected
  • importwinmd

If any of these keywords is used as an identifier, it will generate a build failure indicating a syntax error.

The error will be similar to:

1 >d:\os\src\onecore\com\combase\unittest\astatestservers\testserver6\idl\remreleasetest.idl(12) : error MIDL2025 : [msg]syntax error [context]: expecting a declarator or * near “)”

To fix this, modify the identifier in error to an “@” prefix in front of the identifier. That will cause MIDL to treat the offending element as an identifier instead of a keyword.

About new API updates read more here.