106   bool nothing_;  variable
112 Maybe<T>::Maybe() : nothing_(true) {}  in Maybe()
116   if (!nothing_) {  in ~Maybe()
122 Maybe<T>::Maybe(const Maybe& rhs) : nothing_(rhs.nothing_) {  in Maybe()
123   if (!rhs.nothing_) {  in Maybe()
130 Maybe<T>::Maybe(const Maybe<U>& rhs) : nothing_(rhs.nothing_) {  in Maybe()
131   if (!rhs.nothing_) {  in Maybe()
137 Maybe<T>::Maybe(Maybe&& rhs) noexcept : nothing_(rhs.nothing_) {  in Maybe()
138   if (!rhs.nothing_) {  in Maybe()
139     rhs.nothing_ = true;  in Maybe()
149 Maybe<T>::Maybe(Maybe<U>&& rhs) : nothing_(rhs.nothing_) {  in Maybe()
150   if (!rhs.nothing_) {  in Maybe()
151     rhs.nothing_ = true;  in Maybe()
174   if (nothing_ && rhs.nothing_) {  in copy()
177   } else if (!nothing_ && !rhs.nothing_) {  in copy()
180   } else if (nothing_) {  in copy()
182     nothing_ = rhs.nothing_;  in copy()
188     nothing_ = rhs.nothing_;  in copy()
209   if (nothing_ && rhs.nothing_) {  in move()
212   } else if (!nothing_ && !rhs.nothing_) {  in move()
214     rhs.nothing_ = true;  in move()
218   } else if (nothing_) {  in move()
220     nothing_ = false;  in move()
221     rhs.nothing_ = true;  in move()
228     nothing_ = true;  in move()
235 Maybe<T>::Maybe(const T& value) : nothing_(false) {  in Maybe()
240 Maybe<T>::Maybe(T&& value) : nothing_(false) {  in Maybe()
246   return !nothing_;
251   CHECK(!nothing_) << "Maybe<T>::value() called on Nothing";  in value()
257   CHECK(!nothing_) << "Maybe<T>::value() called on Nothing";  in value()
263   if (nothing_) {  in value_or_default()