[MacPorts] #71685: qt57-qtbase Fails to Configure on Mtn Lion -- "fatal error: 'string_view' file not found"

[MacPorts]

#71685: qt57-qtbase Fails to Configure on Mtn Lion -- "fatal error: 'string_view'
file not found"
--------------------------+------------------------
 Reporter:  RobK88        |      Owner:  (none)
     Type:  defect        |     Status:  new
 Priority:  Normal        |  Milestone:
Component:  ports         |    Version:  2.10.5
 Keywords:  mountainlion  |       Port:  qt5-qtbase
--------------------------+------------------------
 I am unable to upgrade `qt57-qtbase` to @5.7.1_15.  It fails at the
 configure stage.  I see a couple of errors.  See below and the attached
 main.log.


 {{{
 :info:configure /opt/local/include/unicode/uset.h:36:10: fatal error:
 'string_view' file not found
 :info:configure #include <string_view>
 :info:configure          ^
 :info:configure 2 errors generated.
 :info:configure make: *** [icu.o] Error 1
 :info:configure ICU disabled.
 :info:configure The ICU library support cannot be enabled.
 :info:configure  Turn on verbose messaging (-v) to ./configure to see the
 final report.
 :info:configure  If you believe this message is in error you may use the
 continue
 :info:configure  switch (-continue) to ./configure to continue.
 }}}

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Ticket URL: <https://trac.macports.org/ticket/71685>
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