From https://sourceforge.net/tracker/?func=detail&aid=2604261&group_id=158151&atid=806684

As of v.1.4, UnitTest::Check() takes a value by copy, however, due to copy constructors, calling this function can have side effects. I feel it is preferable to pass the value by reference, e.g.

template <typename Value>
Check (Value const& value) {
return !!value;
}

This appears to be an inconsistency with the changes from r178 on sourceforge.