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//! Unix-specific extension to the primitives in the `std::ffi` module

use core::mem;
use ffi::{OsStr, OsString};
use sys::os_str::Buf;
use sys_common::{FromInner, IntoInner, AsInner};

/// Unix-specific extensions to `OsString`.
pub trait OsStringExt {
    /// Creates an [`OsString`] from a byte vector.
    ///
    fn from_vec(vec: Vec<u8>) -> Self;

    /// Yields the underlying byte vector of this [`OsString`].
    ///
    fn into_vec(self) -> Vec<u8>;
}

impl OsStringExt for OsString {
    fn from_vec(vec: Vec<u8>) -> OsString {
        FromInner::from_inner(Buf { inner: vec })
    }
    fn into_vec(self) -> Vec<u8> {
        self.into_inner().inner
    }
}

/// Unix-specific extensions to `OsStr`.
pub trait OsStrExt {
    /// Creates an [`OsStr`] from a byte slice.
    ///
    fn from_bytes(slice: &[u8]) -> &Self;

    /// Gets the underlying byte view of the [`OsStr`] slice.
    ///
    fn as_bytes(&self) -> &[u8];
}

impl OsStrExt for OsStr {
    fn from_bytes(slice: &[u8]) -> &OsStr {
        unsafe { mem::transmute(slice) }
    }
    fn as_bytes(&self) -> &[u8] {
        &self.as_inner().inner
    }
}