2009/10/20 Beman Dawes <bdawes@acm.org>:
Regardless, I'd like to hear Boosters views on the two interfaces above. Which do you prefer? Why?
Since it's neither polymorphic nor ownership-transferring, I really dislike the pointer version. Now, I have no idea how error_code is specified, but I thought it would have been something like this, which wouldn't require null references: struct error_code { static const int throw_instead = ~0; error_code(int c = 0) : code_(c) {} int code() const { return code_; } error_code &operator=(int c) { if (code_ == throw_instead) throw system_exception(c); code_ = c; return *this; } private: int code_; }; error_code throws_object(error_code::throw_instead); error_code &throws() { return throws_object; } That said, I'd much prefer the pointer version to anything that requires that implementation code check whether the address of a reference is null, despite my distaste at having to pass &error all over the place. ~ Scott