error: target of using declaration conflicts with declaration already in scope

[Ben Abbott]

John/others,

I’m seeing the error below on Mac OS X. I’m using Apple’s clang to build.

Apple LLVM version 7.0.2 (clang-700.1.81)
Target: x86_64-apple-darwin14.5.0
Thread model: posix

Bisecting produced the result below.

The first bad revision is:
changeset:   21782:2aef506f3fec
user:        John W. Eaton <address@hidden>
date:        Wed May 25 16:51:16 2016 -0400
summary:     use namespace for lo-mappers.h functions

I’m not proficient enough with c++ to understand what is happening, but am 
happy to attempt a fix if it is easier for someone to explain to me what needs 
to be done. if additional information is needed from my end, please let me know.

Ben

  CXX      libinterp/libinterp_liboctinterp_la-octave.lo
In file included from libinterp/dldfcn/__delaunayn__.cc:50:
In file included from libinterp/corefcn/Cell.h:31:
In file included from ./liboctave/array/Array.h:38:
In file included from ./liboctave/array/idx-vector.h:38:
In file included from ./liboctave/util/oct-inttypes.h:36:
liboctave/numeric/lo-mappers.h:61:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::arg;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:907:1:
 note: target of using declaration
arg(double __re)
^
liboctave/numeric/lo-mappers.h:58:19: note: conflicting declaration
    inline double arg (double x) { return atan2 (0.0, x); }
                  ^
liboctave/numeric/lo-mappers.h:61:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::arg;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:926:1:
 note: target of using declaration
arg(float __re)
^
liboctave/numeric/lo-mappers.h:59:18: note: conflicting declaration
    inline float arg (float x) { return atan2f (0.0f, x); }
                 ^
liboctave/numeric/lo-mappers.h:66:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::conj;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:997:1:
 note: target of using declaration
conj(double __re)
^
liboctave/numeric/lo-mappers.h:63:19: note: conflicting declaration
    inline double conj (double x) { return x; }
                  ^
liboctave/numeric/lo-mappers.h:66:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::conj;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:1016:1:
 note: target of using declaration
conj(float __re)
^
liboctave/numeric/lo-mappers.h:64:18: note: conflicting declaration
    inline float conj (float x) { return x; }
                 ^
liboctave/numeric/lo-mappers.h:71:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::imag;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:854:1:
 note: target of using declaration
imag(double __re)
^
liboctave/numeric/lo-mappers.h:68:19: note: conflicting declaration
    inline double imag (double) { return 0.0; }
                  ^
liboctave/numeric/lo-mappers.h:71:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::imag;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:873:1:
 note: target of using declaration
imag(float  __re)
^
liboctave/numeric/lo-mappers.h:69:18: note: conflicting declaration
    inline float imag (float) { return 0.0f; }
                 ^
liboctave/numeric/lo-mappers.h:76:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::real;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:811:1:
 note: target of using declaration
real(double __re)
^
liboctave/numeric/lo-mappers.h:73:19: note: conflicting declaration
    inline double real (double x) { return x; }
                  ^
liboctave/numeric/lo-mappers.h:76:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::real;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:830:1:
 note: target of using declaration
real(float  __re)
^
liboctave/numeric/lo-mappers.h:74:18: note: conflicting declaration
    inline float real (float x) { return x; }
                 ^
In file included from libinterp/octave.cc:42:
In file included from ./liboctave/util/cmd-edit.h:33:
In file included from ./liboctave/util/str-vec.h:33:
In file included from ./liboctave/array/Array.h:38:
In file included from ./liboctave/array/idx-vector.h:38:
In file included from ./liboctave/util/oct-inttypes.h:36:
liboctave/numeric/lo-mappers.h:61:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::arg;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:907:1:
 note: target of using declaration
arg(double __re)
^
liboctave/numeric/lo-mappers.h:58:19: note: conflicting declaration
    inline double arg (double x) { return atan2 (0.0, x); }
                  ^
liboctave/numeric/lo-mappers.h:61:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::arg;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:926:1:
 note: target of using declaration
arg(float __re)
^
liboctave/numeric/lo-mappers.h:59:18: note: conflicting declaration
    inline float arg (float x) { return atan2f (0.0f, x); }
                 ^
liboctave/numeric/lo-mappers.h:66:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::conj;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:997:1:
 note: target of using declaration
conj(double __re)
^
liboctave/numeric/lo-mappers.h:63:19: note: conflicting declaration
    inline double conj (double x) { return x; }
                  ^
liboctave/numeric/lo-mappers.h:66:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::conj;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:1016:1:
 note: target of using declaration
conj(float __re)
^
liboctave/numeric/lo-mappers.h:64:18: note: conflicting declaration
    inline float conj (float x) { return x; }
                 ^
liboctave/numeric/lo-mappers.h:71:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::imag;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:854:1:
 note: target of using declaration
imag(double __re)
^
liboctave/numeric/lo-mappers.h:68:19: note: conflicting declaration
    inline double imag (double) { return 0.0; }
                  ^
liboctave/numeric/lo-mappers.h:71:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::imag;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:873:1:
 note: target of using declaration
imag(float  __re)
^
liboctave/numeric/lo-mappers.h:69:18: note: conflicting declaration
    inline float imag (float) { return 0.0f; }
                 ^
liboctave/numeric/lo-mappers.h:76:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::real;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:811:1:
 note: target of using declaration
real(double __re)
^
liboctave/numeric/lo-mappers.h:73:19: note: conflicting declaration
    inline double real (double x) { return x; }
                  ^
liboctave/numeric/lo-mappers.h:76:16: error: target of using declaration 
conflicts with declaration already in scope
    using std::real;
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:830:1:
 note: target of using declaration
real(float  __re)
^
liboctave/numeric/lo-mappers.h:74:18: note: conflicting declaration
    inline float real (float x) { return x; }
                 ^
libinterp/dldfcn/__delaunayn__.cc:197:19: warning: use of old-style cast 
[-Wold-style-cast]
                  FOREACHvertex_ (facet->vertices)
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/sw/include/libqhull/libqhull.h:912:34: note: expanded from macro 
'FOREACHvertex_'
#define FOREACHvertex_(vertices) FOREACHsetelement_(vertexT, vertices,vertex)
                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/sw/include/libqhull/qset.h:137:24: note: expanded from macro 
'FOREACHsetelement_'
          variable##p= (type **)&((set)->e[0].p); \
                       ^        ~~~~~~~~~~~~~~~~
1 warning and 8 errors generated.
Makefile:17564: recipe for target 
'libinterp/dldfcn/libinterp_dldfcn___delaunayn___la-__delaunayn__.lo' failed
make[2]: *** 
[libinterp/dldfcn/libinterp_dldfcn___delaunayn___la-__delaunayn__.lo] Error 1
make[2]: *** Waiting for unfinished jobs....
8 errors generated.
Makefile:17704: recipe for target 
'libinterp/libinterp_liboctinterp_la-octave.lo' failed
make[2]: *** [libinterp/libinterp_liboctinterp_la-octave.lo] Error 1
make[2]: Leaving directory 
'/Users/bpabbott/Development/mercurial/default/sources'
Makefile:25413: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory 
'/Users/bpabbott/Development/mercurial/default/sources'
Makefile:9653: recipe for target 'all' failed
make: *** [all] Error 2