/// Extracts a [`CStr`] slice containing the entire string.
///
/// [`CStr`]: struct.CStr.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// #![feature(as_c_str)]
+ ///
+ /// use std::ffi::{CString, CStr};
+ ///
+ /// let c_string = CString::new(b"foo".to_vec()).unwrap();
+ /// let c_str = c_string.as_c_str();
+ /// assert_eq!(c_str, CStr::from_bytes_with_nul(b"foo\0").unwrap());
+ /// ```
#[inline]
#[unstable(feature = "as_c_str", issue = "40380")]
pub fn as_c_str(&self) -> &CStr {