| 14 | { |
| 15 | template <class T> |
| 16 | class optional |
| 17 | { |
| 18 | int key_; |
| 19 | union { T value_; }; |
| 20 | |
| 21 | public: |
| 22 | |
| 23 | typedef T value_type; |
| 24 | |
| 25 | BOOST_LEAF_CONSTEXPR optional() noexcept: |
| 26 | key_(0) |
| 27 | { |
| 28 | } |
| 29 | |
| 30 | BOOST_LEAF_CONSTEXPR optional( optional const & x ): |
| 31 | key_(x.key_) |
| 32 | { |
| 33 | if( x.key_ ) |
| 34 | (void) new (&value_) T( x.value_ ); |
| 35 | } |
| 36 | |
| 37 | BOOST_LEAF_CONSTEXPR optional( optional && x ) noexcept: |
| 38 | key_(x.key_) |
| 39 | { |
| 40 | if( x.key_ ) |
| 41 | { |
| 42 | (void) new (&value_) T( std::move(x.value_) ); |
| 43 | x.reset(); |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | BOOST_LEAF_CONSTEXPR optional( int key, T const & v ): |
| 48 | key_(key), |
| 49 | value_(v) |
| 50 | { |
| 51 | BOOST_LEAF_ASSERT(!empty()); |
| 52 | } |
| 53 | |
| 54 | BOOST_LEAF_CONSTEXPR optional( int key, T && v ) noexcept: |
| 55 | key_(key), |