use std::ffi::{self, CStr};
use std::ptr;
use libc;

/// Consumes and frees the input pointer, and assumes it points to
/// a nul-terminated C-string that contains valid UTF8.
pub unsafe fn string_from_utf8_charp(p: *mut i8) -> String {
    let bytes = CStr::from_ptr(p).to_bytes();
    let res = String::from_utf8(bytes.to_vec()).unwrap();
    libc::free(p as *mut ffi::c_void);
    res
}

pub fn strdup(s: &str) -> *mut i8 {
    unsafe {
        let p: *mut i8 = malloc(s.len() + 1);
        ptr::copy_nonoverlapping(s.as_ptr(), p as *mut u8, s.len());
        *p.add(s.len()) = 0;
        p
    }
}

pub unsafe fn malloc<T>(count: usize) -> *mut T {
    libc::malloc(count * std::mem::size_of::<T>()) as *mut T
}