BOOST_ERROR tool behave the same way as BOOST_CHECK_MESSAGE( false, message ). This tool is used for an unconditional error message logging.
The only tool's parameter is an error message to log.
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
BOOST_AUTO_TEST_CASE( test ) { BOOST_ERROR( "Nothing to test" ); }
Running 1 test case...
test.cpp(6): error in "test": Nothing to test
*** 1 failure detected
in test suite "Master Test Suite"