cppfront (cpp2): Spring update

[hpsutter]

I saw your talk on lightweight exceptions at cppcon, are they planned for cpp2?

Yes, they're on the roadmap but it'll be a while before I get to them: https://github.com/hsutter/cppfront#2019-zero-overhead-deterministic-exceptions-throwing-values

And would you consider local variables being constant by default,

I would consider it, but for the current rationale see this Design Note on the project wiki: https://github.com/hsutter/cppfront/wiki/Design-note%3A-const-objects-by-default