Some test files failed to build due to "error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol"

[BinCaoWR]

The following files failed to build:
../libs/convert/test/performance.cpp:31:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol
../libs/convert/test/spirit_converter.cpp:22:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol
../libs/convert/test/stream_converter.cpp:26:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol
../libs/convert/test/printf_converter.cpp:19:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol
../libs/convert/test/strtol_converter.cpp:166:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol

According to http://www.cplusplus.com/reference/complex/arg/, arg should be declared in complex as below:
complex (1) | template T arg (const complex& x);
arithmetic type (2) |  double arg (ArithmeticType x); // additional overloads

As a result, the arg declared in boost test files should be renamed.

[yet-another-user]

Thank you for your input. Much appreciated. Would you mind to clarify under what circumstances it fails to build... because 1) it builds on my machine (ubuntu); 2) it builds and runs in Boorst regression (https://www.boost.org/development/tests/develop/developer/convert.html). From what I understand the "arg" you reference is, in fact, in the std namspace, i.e. std::arg declared in ... which I do not see even included in the mentioned cpp files. SO, again, would you mind shedding some light on how the problem pops up? Thanks.

[BinCaoWR]

Thanks for your quick response. I build the tests on gcc-8.1.0 & C++14. If it cannot be reproduced in your environment, it would be probably due to arg is not declared in your complex.h on the C++/toolchain version you are using.
Here is the info about how complex can be included in the boost cpp files.

../libs/convert/test/performance.cpp: At global scope:
../libs/convert/test/performance.cpp:31:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol
namespace arg = boost::cnv::parameter;
^
In file included from ccomplex:16,
from complex:5,
from boost_1_70_0/boost/type_traits/is_complex.hpp:12,
from boost_1_70_0/boost/type_traits.hpp:96,
from boost_1_70_0/boost/convert/detail/is_fun.hpp:11,
from boost_1_70_0/boost/convert.hpp:28,
from ../libs/convert/test/performance.cpp:13:
complex.h:664:20: note: previous declaration 'long double arg(_Lcomplex)'
inline long double arg(_Lcomplex _Left)
^~~

[yet-another-user]

Indeed, I use g++-7.4.0 and it does not have "arg" defined in ccomplex. I'll look into fixing it. Still, I am really curious why that does not fail in regression tests. https://www.boost.org/development/tests/develop/developer/convert.html shows that all compiled on gcc- 8~c++11, gcc- 8~c++14, etc. Any idea why that might be? Tnx.

…

On Wed, May 29, 2019 at 12:28 PM BinCaoWR ***@***.***> wrote: Thanks for your quick response. I build the tests on gcc-8.1.0 & C++14. If it cannot be reproduced in your environment, it would be probably due to arg is not declared in your complex.h on the C++/toolchain version you are using. Here is the info about how complex can be included in the boost cpp files. ../libs/convert/test/performance.cpp: At global scope: ../libs/convert/test/performance.cpp:31:38: error: 'namespace arg = boost::cnv::boost::cnv::parameter;' redeclared as different kind of symbol namespace arg = boost::cnv::parameter; ^ In file included from ccomplex:16, from complex:5, from boost_1_70_0/boost/type_traits/is_complex.hpp:12, from boost_1_70_0/boost/type_traits.hpp:96, from boost_1_70_0/boost/convert/detail/is_fun.hpp:11, from boost_1_70_0/boost/convert.hpp:28, from ../libs/convert/test/performance.cpp:13: complex.h:664:20: note: previous declaration 'long double arg(_Lcomplex)' inline long double arg(_Lcomplex _Left) ^~~ — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#45?email_source=notifications&email_token=AANTAIDV2VOP2EPGEEPIHR3PXXS6DA5CNFSM4HQARZAKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODWN7DNA#issuecomment-496759220>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AANTAIBAMRMEYBHO2Q6O5GTPXXS6DANCNFSM4HQARZAA> .

[BinCaoWR]

I'm not sure why the boost regression can pass. Perhaps need to confirm if is_complex.hpp is included and how arg(the conditionals, etc) is defined in complex.

[yet-another-user]

I have no forgotten about the issue. Just recently upgraded to gcc-8.3. Will be trying to see why tat might be failing... because IMO it should not. :-)

[yet-another-user]

Can't reproduce. Closing.