BloombergLP::bdlb::NullableAllocatedValue::emplace

Assign to this object the value of the (template parameter) TYPE created in place using the specified args and return a reference providing modifiable access to the underlying TYPE object. If this optional object already contains an object (`true == hasValue()`), that object is destroyed before the new object is created. Note that if the constructor of TYPE throws an exception this object is left in a disengaged state.