42 struct maybe : maybe_base  struct
50     >::type reference;
54     >::type non_cv_value;
56     explicit maybe(T value_)  in maybe()  argument
61     maybe()  in maybe()  argument
65     ~maybe()  in ~maybe()
71     reference construct(reference value_) const  in construct()
77     reference construct2(U const& value_) const  in construct2()
85     reference construct(U const& value_) const  in construct()
90     void destroy()  in destroy()
95     typedef reference(maybe<T>::*safe_bool)() const;
97     operator safe_bool() const  in operator safe_bool()
102     reference get() const  in get()
108     boost::optional<T> value;
109     mutable bool constructed;
114     >::type m_storage;