The init_unit_test_func function typedef identifies the signature of the user supplied initialization function. The initialization function can be used to add custom test cases and test suites to the test tree.

namespace boost { namespace unit_test {

#ifdef BOOST_TEST_ALTERNATIVE_INIT_API
typedef bool        (*init_unit_test_func)();
#else
typedef test_suite* (*init_unit_test_func)( int, char* [] );
#endif

} }