You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: interfaces.rs
    path of file: ./repos/vst-rs/src
    
    the code of the file until where you have to start completion: //! Function interfaces for VST 2.4 API.

#![doc(hidden)]

use std::cell::Cell;
use std::os::raw::{c_char, c_void};
use std::{mem, slice};

use
    
fn copy_string(dst: *mut c_void, src: &str, max: usize) -> isize {
    unsafe {
        use libc::{memcpy, memset};
        use std::cmp::min;

        let dst = dst as *mut c_void;
        memset(dst, 0, max);
        memcpy(dst, src.as_ptr() as *const c_void, min(max, src.as_bytes().len()));
    }

    1 // Success
}