CheckIPOSupport(ed)
https://cmake.org/cmake/help/git-master/policy/CMP0069.html (master as well as 3.9, etc) currently mixes CheckIPOSupport
and CheckIPOSupported
, as well as check_ipo_support
and check_ipo_supported
, especially in the examples. In both cases, the former is wrong and will not work. It should always have the ed
at the end.