d314e8a818d4c162b1c7201533e6b600dcab2d91 refactor: Replace all uses of boost::optional with our own Optional type (Wladimir J. van der Laan)
Pull request description:
Replace all uses of boost::optional with our own Optional type. Luckily, there aren't so many.
After this:
- `boost::optional` is no longer used directly (only through `Optional` which is an alias for it)
- `boost/optional.hpp` is only included in one place
ACKs for top commit:
MarcoFalke:
ACK d314e8a818d4c162b1c7201533e6b600dcab2d91
practicalswift:
ACK d314e8a818d4c162b1c7201533e6b600dcab2d91 -- diff looks correct + satisfying to see incremental progress towards the goal of a Boost free future :)
jtimon:
ACK d314e8a818d4c162b1c7201533e6b600dcab2d91
fanquake:
ACK d314e8a818d4c162b1c7201533e6b600dcab2d91
Tree-SHA512: b43e0017af81b07b5851377cd09624f114510ac5b9018d037664b58ad0fc8e893e30946b61f8f5e21e39125925bf9998a81f2226b468aab2df653ee57ed3213d
08e2947312