[MacPorts] #63460: cmake-3.21.2_0 fails to configure on older Xcode clang versions

[MacPorts]

#63460: cmake-3.21.2_0 fails to configure on older Xcode clang versions
---------------------+----------------------------
  Reporter:  tehcog  |      Owner:  michaelld
      Type:  defect  |     Status:  assigned
  Priority:  High    |  Milestone:
 Component:  ports   |    Version:  2.7.1
Resolution:          |   Keywords:  lion mavericks
      Port:  cmake   |
---------------------+----------------------------

Comment (by michaelld):

 Beyond trying out actual C++ code, is there a way to test whether a
 compiler supports given `-std=c++***` or `-std=gnu++***` arguments? Have
 to do some web searching to see ... but maybe someone here knows faster
 than me :)

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Ticket URL: <https://trac.macports.org/ticket/63460#comment:17>
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