Create a disengaged optional object if the specified original object is disengaged, and an optional object with the value of original.value() moved and converted to t_TYPE otherwise. Use the specified allocator to supply memory. original is left in a valid but unspecified state. Note that this constructor participates in overload resolution only when t_TYPE is constructible from an xvalue of t_ANY_TYPE, and is implicit only when an xvalue of t_ANY_TYPE is implicitly convertible to t_TYPE.
Declared in <bslstl_optional.h>
template<class t_ANY_TYPE>
optional(
std::allocator_arg_t,
AllocType allocator,
BloombergLP::bslmf::MovableRef_Deduced<optional<t_ANY_TYPE>> original);