id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3444	BOOST_CHECK_MESSAGE - 2 problems	Maxim Yanchenko <Maxim.Yanchenko@…>	Gennadiy Rozental	"1) The 2nd argument is always evaluated.
I believe it's natural for a user to expect that BOOST_CHECK_MESSAGE follows short circuit logic, i.e. if the check was satisfied, no more user code is called.

Example:
{{{
BOOST_CHECK_MESSAGE( x == y, report_non_equal(x,y) )
}}}

report_non_equal(x,y) should be evaluated only if the check failed, as a natural precondition for the report_non_equal is that its arguments are not equal (e.g. a user can divide something by the difference of x and y without checking that it's not zero).

2) The message is printed even in case of success with --log_level=success.
People usually place there a message like ""failed"" in the message.
For example, see the Boost regression test suite (just picked a couple of examples):
{{{
./libs/test/test/test_tools_test.cpp:210:    BOOST_CHECK_MESSAGE( test_pred1(), ""Checking predicate failed"" )
./libs/iostreams/test/large_file_test.cpp:382:    BOOST_CHECK_MESSAGE(amt == 1, ""failed reading character"");
./libs/serialization/test/test_non_intrusive.cpp:152:    BOOST_CHECK_MESSAGE(pa1 == &a, ""Copy of pointer not correctly restored"");
}}}
And the Boost.Test docs is not an exception:
{{{
BOOST_WARN_MESSAGE( res > 1, ""sin(45){"" << res << ""} is <= 1. Hmm.. Strange. "" );
}}}
As you can see, the message users provide usually describes the failure (""X failed""), not the test itself (""testing X"").
So when they use --log_level=success they are very confused when they see that something successfully failed (as a message from UTF ""check 'X failed' passed"" means that the failure X was expected).

In my case, I used the message to report the position where two strings mismatched using simple ""std::mismatch-begin"" (naturally expecting it to be called only in a case of failure), so with --log_level=success it printed that all strings mismatched in their end with funny and ambiguous messages like
""info: check 'Strings ""asd"" and ""asd"" mismatch at position 3' passed""
(does it mean that they were expected to mismatch at pos 3?), while they worked perfectly when the check failed:
""error in ""test"": Strings ""asd"" and ""asx"" mismatch at position 2""

I believe if you run Boost regression test suite with --log_level=success you will see a lot of similar absurd messages.



From the first glance, the fix for both problems seems obvious (haven't tried yet, though) - in case of BOOST_<level>_MESSAGE the following version of BOOST_CHECK_IMPL should be used:
{{{
#define BOOST_CHECK_IMPL( P, check_descr, TL, CT )                         \
do {                                                                       \
    BOOST_TEST_PASSPOINT();                                                \
    const bool result = P;                                                 \
    if (result)                                                            \
      BOOST_TEST_TOOL_IMPL( check_impl, result, BOOST_TEST_STRINGIZE( P ), TL, CT ), 0 );         \
    else                                                                   \
      BOOST_TEST_TOOL_IMPL( check_impl, result, check_descr, TL, CT ), 0 );\
} while( ::boost::test_tools::dummy_cond )                                 \
/**/
                       
}}}"	Bugs	closed	Boost 1.41.0	test	Boost 1.38.0	Problem	wontfix