[Boost-bugs] [Boost C++ Libraries] #10467: Boost.Geometry fails to compile on OS X if sys/termios.h is included

Subject: [Boost-bugs] [Boost C++ Libraries] #10467: Boost.Geometry fails to compile on OS X if sys/termios.h is included
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-05 14:57:32

#10467: Boost.Geometry fails to compile on OS X if sys/termios.h is included
------------------------------+---------------------------
 Reporter:  nneonneo          |      Owner:  barendgehrels
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  geometry
  Version:  Boost 1.56.0      |   Severity:  Regression
 Keywords:                    |
------------------------------+---------------------------
 On OS X, sys/termios.h defines the symbol B0 as 0.

 With Boost 1.56.0, including sys/termios.h before
 boost/geometry/algorithms/assign.hpp causes a compilation failure which
 looks like this:

 {{{
 In file included from test.cpp:2:
 /opt/local/include/boost/geometry/algorithms/assign.hpp:320:50: error:
 expected a qualified name after 'typename'
 template <BOOST_VARIANT_ENUM_PARAMS(typename A),
 BOOST_VARIANT_ENUM_PARAMS(typename B)>
                                                  ^
 /opt/local/include/boost/variant/variant_fwd.hpp:164:5: note: expanded
 from macro 'BOOST_VARIANT_ENUM_PARAMS'
     BOOST_PP_ENUM_PARAMS(BOOST_VARIANT_LIMIT_TYPES, param)
     ^
 /opt/local/include/boost/preprocessor/repetition/enum_params.hpp:24:71:
 note: expanded from macro 'BOOST_PP_ENUM_PARAMS'
 #    define BOOST_PP_ENUM_PARAMS(count, param) BOOST_PP_REPEAT(count,
 BOOST_PP_ENUM_PARAMS_M, param)
                                                                       ^
 /opt/local/include/boost/preprocessor/repetition/repeat.hpp:38:60: note:
 expanded from macro 'BOOST_PP_REPEAT_1'
 # define BOOST_PP_REPEAT_1(c, m, d) BOOST_PP_REPEAT_1_I(c, m, d)
                                                            ^
 note: (skipping 21 expansions in backtrace; use -fmacro-backtrace-limit=0
 to see all)
 /opt/local/include/boost/preprocessor/repetition/enum_params.hpp:30:67:
 note: expanded from macro 'BOOST_PP_ENUM_PARAMS_M'
 # define BOOST_PP_ENUM_PARAMS_M(z, n, param) BOOST_PP_COMMA_IF(n) param ##
 n
                                                                   ^
 <scratch space>:13:1: note: expanded from here
 B0
 ^
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/sys/termios.h:291:12:
 note: expanded from
       macro 'B0'
 #define B0      0
                 ^
 }}}

 The problem is that BOOST_VARIANT_ENUM_PARAMS(typename B) expands to a
 series of type params including "typename B0", which is then further
 expanded to "typename 0" by the B0 macro, and that causes a compilation
 failure.

 This is a regression: the observed behaviour did not appear under Boost
 1.55.0.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10467>
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