On 21.11.2011, at 18:24, Andrzej Krzemienski wrote:
Interesting. It looks like optional can be seen as a special container with the maximum size of 1, and then functions like clear() or empty() come as natural. On the other hand it can be seen as a pointer-like entity with value semantics, and then functions like reset() and literal nullptr come as natural.
Ok, I have no strong preference between reset() or clear() for making the optional empty. However, a explicit empty() member would be useful anyway.
class MyClass { optional< int > m_x;
public: bool has_x() const { return !m_x.empty(); } };
I think, providing the reset() member with construction semantic is not a good idea because it would make imposible in-place default construction. There should be another method that would handle construction. In another post I suggested assign() but I'm happy if someone comes up with a better name.
I managed to come up with the following interface for initializing and un-initializing. My goal was also to not introduce in-place factories.
Initialize sounds slightly wrong. I like the notion of optional as something like a single-element container, which would lead to the names emplace() for in-place construction, clear() for resetting to the none-state, and empty() as the test function. (Maybe with a positive filled() too.) Sebastian