[MacPorts] #70351: legacy-support implementation of sincos does not work correctly: implicit declaration of function 'sincos'

[MacPorts]

#70351: legacy-support implementation of sincos does not work correctly: implicit
declaration of function 'sincos'
-----------------------------+--------------------
  Reporter:  barracuda156    |      Owner:  (none)
      Type:  defect          |     Status:  new
  Priority:  Normal          |  Milestone:
 Component:  ports           |    Version:  2.9.3
Resolution:                  |   Keywords:
      Port:  legacy-support  |
-----------------------------+--------------------

Comment (by fhgwright):

 Actually, ''no'' Apple header provides a prototype for `sincos`, since
 it's an "extension".  This is true even in the latest (15.x) SDK.  From
 `math.h`:
 {{{
 /*  Because these functions are not specified by any relevant standard,
 they
     are prefixed with __, which places them in the implementor's
 namespace, so
     they should not conflict with any developer or third-party code.  If
 they
     are added to a relevant standard in the future, un-prefixed names may
 be
     added to the library and they may be moved out of this section of the
     header.

     Because these functions are non-standard, they may not be available on
 non-
     Apple platforms.
 */
 }}}
 All `legacy-support` does is add the missing `__sincos` (and `__sincosf`)
 for the earlier OS versions that didn't have them.  Making `__sincos`
 available as `sincos` is left as an exercise for the reader.

 As far as `legacy-support` is concerned, this is Working As Intended (TM).

-- 
Ticket URL: <https://trac.macports.org/ticket/70351#comment:7>
MacPorts <https://www.macports.org/>
Ports system for macOS