# Host files File path: `out/dir/api.rs` ```rust // Host code /* Rust API */ #[derive(Debug)] pub enum Commands { /// Call out an outstanding person #[allow(non_camel_case_types)] call_me_back_outstanding { callback: fn(String) -> String }, One(one::One), } pub mod one { #[derive(Debug)] pub enum One { /// Call out a person #[allow(non_camel_case_types)] call_me_back { callback: fn(u32) }, } } /* C API */ #[no_mangle] pub extern "C" fn call_me_back_outstanding( callback: fn(String) -> String, ) -> core::ffi::c_int { callback_function(call_me_back_outstanding); return 1; } pub mod one_c {} #[no_mangle] pub extern "C" fn one_call_me_back(callback: fn(u32)) -> core::ffi::c_int { callback_function(one_call_me_back); return 1; } // vim: filetype=rust ``` # Auxiliary files File path: `dist/interface.h` ```c #if !defined TRIXY_MAIN_HEADER #define TRIXY_MAIN_HEADER #include "errno.h" #include "string.h" #include "vec.h" /** * Call out an outstanding person */ extern int call_me_back_outstanding (const char *(*callback) (const char *)); /** * Call out a person */ extern int one_call_me_back (void (*callback) (uint32_t)); struct one { int (*call_me_back) (); }; const struct one one = { .call_me_back = one_call_me_back, }; #endif // if !defined TRIXY_MAIN_HEADER // vim: filetype=c ```