On 2/03/2016 11:51, Andrzej Krzemienski wrote:
At some earlier stages of development, boost::optional did not have the assignment from boost::none_t (and probably also from T); and reset was the only way to efficiently change the optional from the state of having the value to the state of not having the value.
After the addition of more fancy syntax (conversion to bool, assignment from none_t), reset() (and is_initialized()) became redundant, and hence the deprecation.
It still bothers me a bit that none and nullptr are separate. Do we really need two different ways to spell "nothing"? I suppose there is a use case for optional<some-pointer-type> which could have distinct states for "no pointer" vs. "null pointer" vs. "valid pointer", but how often do you really need to distinguish the first two states? (Although I guess if you didn't want to distinguish them, you'd just use some-pointer-type directly instead of wrapping it in an optional. So I understand the presumed rationale, it just seems weird.)