For the latest documentation on Visual Studio 2017, see Visual Studio 2017 Documentation.
For the latest documentation on Visual Studio 2017, see C28215 on docs.microsoft.com. warning C28215: The typefix cannot be applied to a parameter that already has a typefix
__typefix annotation to a parameter that already has that annotation is an error. The
__typefix annotations are used only in a few special cases and this warning is not expected to be seen in normal use.