- Strings and symbols passed to foreign code are not copied, they are passed directly, any mutations done by external code will be visible on the Scheme

- Strings and symbols passed to foreign code are not copied, they are passed directly, any mutations done by external code will be visible on the Scheme side. - Complex numbers, C structs and unions can now be passed directly as arguments and returned as results when interfacing to C code. Those were major bottlenecks for any FFI-heavy Chicken Scheme app, and would often result in brittle and unsafe abstractions to work around. Glad to see this changed.