[Boost-users] [Test] BOOST_CHECK_EXCEPTION error message still vague

Subject: [Boost-users] [Test] BOOST_CHECK_EXCEPTION error message still vague
From: Merrill Cornish (merrill.cornish_at_[hidden])
Date: 2016-02-05 13:06:18

In BOOST_1_59_0, I complained that the error message from 
BOOST_CHECK_EXCEPTION was indecipherable.  In BOOST_1_60_0, things 
improved a lot.  But it still leave you hanging.

I use the function fail_msg() as the predicate argument to 
BOOST_CHECK_EXCEPTION.  If it finds a specified substring in the 
exception message, it returns true.  Otherwise, it returns false. Below 
is an error message from BOOST_CHECK_EXCEPTION when the predicate 
returned false:

  exception "std::runtime_error" raised as expected: validation on the 
raised exception through predicate "fail_msg"

The first clause says my code raised the expected exception class. That 
part of the message is clear and unambiguous.

The second clause, however, is a non-sequitur.  It seems to only 
acknowledge that there was a predicate named "fail_msg" without saying 
whether it returned true or false.  Overall, the whole message doesn't 
say whether BOOST_CHECK_EXCEPTION passed or failed. Since a message was 
output, the user can assume things did not go well, but it seems like 
the message could be more explicit.

Merrill Cornish