[boost] [test]redefinition of boost::unit_test::ut_detail::auto_test_unit_registrar

Subject: [boost] [test]redefinition of boost::unit_test::ut_detail::auto_test_unit_registrar
From: Takatoshi Kondo (redboltz_at_[hidden])
Date: 2017-02-13 14:39:50

Hello,

I'm using Boost.Test.

When I define BOOST_AUTO_TEST_SUITE, I got a compile error
'redefinition of
boost::unit_test::ut_detail::auto_test_unit_registrar' if the all
following conditions are satisfied:

1. The test suite names are the same.
2. BOOST_AUTO_TEST_SUITE are defined in different files.
3. The files are included by one file.
4. BOOST_AUTO_TEST_SUITE are defined at the same line number.

For example,

main.cpp

#define BOOST_TEST_MODULE test
#include <boost/test/unit_test.hpp>

#include "one.ipp"
#include "two.ipp"

one.ipp

BOOST_AUTO_TEST_SUITE(a)
    BOOST_AUTO_TEST_CASE(tc1) {
    }
BOOST_AUTO_TEST_SUITE_END()

two.ipp

BOOST_AUTO_TEST_SUITE(a)
    BOOST_AUTO_TEST_CASE(tc2) {
    }
BOOST_AUTO_TEST_SUITE_END()

Here is a live demo:
http://melpon.org/wandbox/permlink/R459VQ6apnQfapyw

If I insert a line the top of two.ipp, no errors are occurred.

http://melpon.org/wandbox/permlink/jPRTstNDVb7agjXl

According to the following document
http://www.boost.org/doc/libs/1_63_0/libs/test/doc/html/boost_test/tests_organization/test_suite.html#ref_BOOST_AUTO_TEST_SUITE

"The same test suite can be restarted multiple times inside the same
test file or in a different test files."

The compile error is caused by the following line:
https://github.com/boostorg/test/blob/develop/include/boost/test/unit_test_suite.hpp#L326

If I replace
BOOST_JOIN( BOOST_JOIN( test_name, _registrar ), __LINE__ ) \
with
BOOST_JOIN( BOOST_JOIN( test_name, _registrar ), __COUNTER__ ) \
, then the error is disappeared.

However, __COUNTER__ is not portable.

I know that I can compile one.ipp and two.ipp separately, but I also
want to have the option that include them from one file.

Is there any good way to solve the error?

Thanks,
Takatoshi Kondo