小编Moc*_*ida的帖子

所以我只是在 Rust 中修改 C 库，我发现以下代码：

extern crate libc;
use libc::{c_char, c_int, size_t};


extern "C" {

    fn printf(fmt: *const c_char, ...) -> c_int;
    
    fn strlen(arr: *const c_char) -> size_t;
}

fn main() {
    unsafe {
        printf("This uses C's standard lib printf".as_ptr() as *const i8);
        print!("\n");
        let s = "Useless thing again";
        print!("Length of {}: ", s);
        let x = strlen(s.as_ptr() as *const i8);
        print!("{}", &x);
    }
}

将产生这个：

This uses C's standard lib printf

Length of Useless thing again: 31  

strlen() …