[CMake] regex ^ does not anchor against the original string

[Brandon Van Every]

^ doesn't anchor against the original input string.  It anchors
against the string as it is processed!  If replacements cause the
string to have a new beginning, it anchors against the new beginning.
I want to say that's a bug.  Do other regex gurus agree, or have I
just not gone up the learning curve sufficiently?

SET(problem " else else else else else")
MESSAGE("original string:")
MESSAGE("${problem}")
MESSAGE("expecting replacement to have 4 else's.  Instead we get:")
STRING(REGEX REPLACE
  "^.else"
  ""
  out "${problem}")
MESSAGE("${out}")

C:\devel\moz>cmake -P sideeffect.cmake
original string:
 else else else else else
expecting replacement to have 4 else's.  Instead we get:


C:\devel\moz>


Cheers,
Brandon Van Every