* Plain Structs
* Rich enums (aka: Algebraic types) that leads to
* All replacements to nulls (Option, Result, Default(trait), Empty(idiom))
* Immutability and functional style as preferred when sensible
* Consistency in APIs by proxy of traits (all conversions going with Into/From traits, All iterables can .collect into all containers, etc)
and many things like this that make very productive to build good APIs when you get the handle of it.
According to dtolnay, there are only 4 lines of unsafe rust in the Rust component. It's a bit small though at the current moment in time, with 4 thousand lines. Most of the code is still C++. Note that it's "with Rust" in the headline, not "in Rust".
??? Android crash little things left and right, and have leaks just for existing.