CMAKE_MATCH_<n>ΒΆ
New in version 3.9.
Capture group <n> matched by the last regular expression, for groups
0 through 9. Group 0 is the entire match. Groups 1 through 9 are the
subexpressions captured by () syntax.
When a regular expression match is used, CMake fills in CMAKE_MATCH_<n>
variables with the match contents. The CMAKE_MATCH_COUNT
variable holds the number of match expressions when these are filled.