this repo wanna demo the pointer conversion usage in c-rust FFI calling.
below is the folder tree:
.
├── build.rs
├── Cargo.lock
├── Cargo.toml
├── c_src
│ ├── gen.c
│ └── gen.h
└── src
└── main.rs
2 directories, 6 files
in c_src we separate the header and impl.
we declare the necessary func as extern C in main.rs
// main.rs:5
extern "C" {
fn for_each_interesting_number(callback: extern "C" fn(i32, *mut c_void), data: *mut c_void);
}
and for build.rs this is a build an entry, the content is really straightforward.
// build.rs
fn main() {
cc::Build::new()
.file("c_src/gen.c")
.compile("my_library");
}
the detailed pretest shall be found in main.rs content.