https://github.com/martinmoene/optional-bare/blob/0bb1d183bcee1e854c4ea196b533252c51f98b81/include/nonstd/optional.hpp#L179
May be I don't understand something, but how this line is supposed to work if method value() always checks assert(has_value())
?
As i understand it we will always get exception when trying to copy empty optional.