1 files changed, 963 insertions, 0 deletions
diff --git a/vendor/rustix/src/path/arg.rs b/vendor/rustix/src/path/arg.rs
new file mode 100644
index 000000000..7f66f71f2
--- /dev/null
+++ b/vendor/rustix/src/path/arg.rs
@@ -0,0 +1,963 @@
+//! Convenient and efficient string argument passing.
+//!
+//! This module defines the `Arg` trait and implements it for several common
+//! string types. This allows users to pass any of these string types directly
+//! to rustix APIs with string arguments, and it allows rustix to implement
+//! NUL-termination without the need for copying where possible.
+
+use crate::ffi::{CStr, CString};
+use crate::io;
+#[cfg(feature = "itoa")]
+use crate::path::DecInt;
+use crate::path::SMALL_PATH_BUFFER_SIZE;
+use alloc::borrow::Cow;
+#[cfg(feature = "itoa")]
+use alloc::borrow::ToOwned;
+use alloc::string::String;
+use alloc::vec::Vec;
+use core::str;
+#[cfg(feature = "std")]
+use std::ffi::{OsStr, OsString};
+#[cfg(feature = "std")]
+#[cfg(target_os = "hermit")]
+use std::os::hermit::ext::ffi::{OsStrExt, OsStringExt};
+#[cfg(feature = "std")]
+#[cfg(unix)]
+use std::os::unix::ffi::{OsStrExt, OsStringExt};
+#[cfg(feature = "std")]
+#[cfg(target_os = "vxworks")]
+use std::os::vxworks::ext::ffi::{OsStrExt, OsStringExt};
+#[cfg(feature = "std")]
+#[cfg(target_os = "wasi")]
+use std::os::wasi::ffi::{OsStrExt, OsStringExt};
+#[cfg(feature = "std")]
+use std::path::{Component, Components, Iter, Path, PathBuf};
+
+/// A trait for passing path arguments.
+///
+/// This is similar to [`AsRef`]`<`[`Path`]`>`, but is implemented for more
+/// kinds of strings and can convert into more kinds of strings.
+///
+/// # Example
+///
+/// ```rust
+/// # #[cfg(any(feature = "fs", feature = "net"))]
+/// use rustix::ffi::CStr;
+/// use rustix::io;
+/// # #[cfg(any(feature = "fs", feature = "net"))]
+/// use rustix::path::Arg;
+///
+/// # #[cfg(any(feature = "fs", feature = "net"))]
+/// pub fn touch<P: Arg>(path: P) -> io::Result<()> {
+///     let path = path.into_c_str()?;
+///     _touch(&path)
+/// }
+///
+/// # #[cfg(any(feature = "fs", feature = "net"))]
+/// fn _touch(path: &CStr) -> io::Result<()> {
+///     // implementation goes here
+///     Ok(())
+/// }
+/// ```
+///
+/// Users can then call `touch("foo")`, `touch(cstr!("foo"))`,
+/// `touch(Path::new("foo"))`, or many other things.
+///
+/// [`AsRef`]: std::convert::AsRef
+pub trait Arg {
+    /// Returns a view of this string as a string slice.
+    fn as_str(&self) -> io::Result<&str>;
+
+    /// Returns a potentially-lossy rendering of this string as a `Cow<'_,
+    /// str>`.
+    fn to_string_lossy(&self) -> Cow<'_, str>;
+
+    /// Returns a view of this string as a maybe-owned [`CStr`].
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>>;
+
+    /// Consumes `self` and returns a view of this string as a maybe-owned
+    /// [`CStr`].
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b;
+
+    /// Runs a closure with `self` passed in as a `&CStr`.
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>;
+}
+
+impl Arg for &str {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        Ok(self)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(*self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+impl Arg for &String {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        Ok(self)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(String::as_str(self)).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        self.as_str().into_c_str()
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+impl Arg for String {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        Ok(self)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_str()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(&CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for &OsStr {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        OsStr::to_string_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for &OsString {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        OsString::as_os_str(self).to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_os_str().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(OsString::as_os_str(self).as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        self.as_os_str().into_c_str()
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for OsString {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_os_str().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_os_str().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.into_vec()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(&CString::new(self.into_vec()).map_err(|_cstr_err| io::Errno::INVAL)?)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for &Path {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_os_str().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Path::to_string_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_os_str().as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_os_str().as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_os_str().as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for &PathBuf {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        PathBuf::as_path(self)
+            .as_os_str()
+            .to_str()
+            .ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_path().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(PathBuf::as_path(self).as_os_str().as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        self.as_path().into_c_str()
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_os_str().as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl Arg for PathBuf {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_os_str().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_os_str().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_os_str().as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.into_os_string().into_vec()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(
+            &CString::new(self.into_os_string().into_vec())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        )
+    }
+}
+
+impl Arg for &CStr {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.to_str().map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        CStr::to_string_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(self)
+    }
+}
+
+impl Arg for &CString {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        unimplemented!()
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        unimplemented!()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(self)
+    }
+}
+
+impl Arg for CString {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.to_str().map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        CStr::to_string_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(self))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(&self)
+    }
+}
+
+impl<'a> Arg for Cow<'a, str> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        Ok(self)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_ref()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            match self {
+                Cow::Owned(s) => CString::new(s),
+                Cow::Borrowed(s) => CString::new(s),
+            }
+            .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'a> Arg for Cow<'a, OsStr> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        (**self).to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        (**self).to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            match self {
+                Cow::Owned(os) => CString::new(os.into_vec()),
+                Cow::Borrowed(os) => CString::new(os.as_bytes()),
+            }
+            .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_bytes(), f)
+    }
+}
+
+impl<'a> Arg for Cow<'a, CStr> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.to_str().map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        let borrow: &CStr = core::borrow::Borrow::borrow(self);
+        borrow.to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Borrowed(self))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(self)
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(&self)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'a> Arg for Component<'a> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_os_str().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_os_str().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_os_str().as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_os_str().as_bytes()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_os_str().as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'a> Arg for Components<'a> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_path().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_path().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_path().as_os_str().as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_path().as_os_str().as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_path().as_os_str().as_bytes(), f)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'a> Arg for Iter<'a> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        self.as_path().to_str().ok_or(io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        self.as_path().to_string_lossy()
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_path().as_os_str().as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_path().as_os_str().as_bytes())
+                .map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self.as_path().as_os_str().as_bytes(), f)
+    }
+}
+
+impl Arg for &[u8] {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        str::from_utf8(self).map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        String::from_utf8_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(*self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self, f)
+    }
+}
+
+impl Arg for &Vec<u8> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        str::from_utf8(self).map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        String::from_utf8_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_slice()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self.as_slice()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        with_c_str(self, f)
+    }
+}
+
+impl Arg for Vec<u8> {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        str::from_utf8(self).map_err(|_utf8_err| io::Errno::INVAL)
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        String::from_utf8_lossy(self)
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Owned(
+            CString::new(self.as_slice()).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(
+            CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?,
+        ))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(&CString::new(self).map_err(|_cstr_err| io::Errno::INVAL)?)
+    }
+}
+
+#[cfg(feature = "itoa")]
+impl Arg for DecInt {
+    #[inline]
+    fn as_str(&self) -> io::Result<&str> {
+        Ok(self.as_str())
+    }
+
+    #[inline]
+    fn to_string_lossy(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self.as_str())
+    }
+
+    #[inline]
+    fn as_cow_c_str(&self) -> io::Result<Cow<'_, CStr>> {
+        Ok(Cow::Borrowed(self.as_c_str()))
+    }
+
+    #[inline]
+    fn into_c_str<'b>(self) -> io::Result<Cow<'b, CStr>>
+    where
+        Self: 'b,
+    {
+        Ok(Cow::Owned(self.as_c_str().to_owned()))
+    }
+
+    #[inline]
+    fn into_with_c_str<T, F>(self, f: F) -> io::Result<T>
+    where
+        Self: Sized,
+        F: FnOnce(&CStr) -> io::Result<T>,
+    {
+        f(self.as_c_str())
+    }
+}
+
+/// Runs a closure with `bytes` passed in as a `&CStr`.
+#[inline]
+fn with_c_str<T, F>(bytes: &[u8], f: F) -> io::Result<T>
+where
+    F: FnOnce(&CStr) -> io::Result<T>,
+{
+    // Most paths are less than `SMALL_PATH_BUFFER_SIZE` long. The rest can go
+    // through the dynamic allocation path. If you're opening many files in a
+    // directory with a long path, consider opening the directory and using
+    // `openat` to open the files under it, which will avoid this, and is often
+    // faster in the OS as well.
+
+    // Test with >= so that we have room for the trailing NUL.
+    if bytes.len() >= SMALL_PATH_BUFFER_SIZE {
+        return with_c_str_slow_path(bytes, f);
+    }
+    let mut buffer: [u8; SMALL_PATH_BUFFER_SIZE] = [0_u8; SMALL_PATH_BUFFER_SIZE];
+    // Copy the bytes in; the buffer already has zeros for the trailing NUL.
+    buffer[..bytes.len()].copy_from_slice(bytes);
+    f(CStr::from_bytes_with_nul(&buffer[..=bytes.len()]).map_err(|_cstr_err| io::Errno::INVAL)?)
+}
+
+/// The slow path which handles any length. In theory OS's only support up
+/// to `PATH_MAX`, but we let the OS enforce that.
+#[cold]
+fn with_c_str_slow_path<T, F>(bytes: &[u8], f: F) -> io::Result<T>
+where
+    F: FnOnce(&CStr) -> io::Result<T>,
+{
+    f(&CString::new(bytes).map_err(|_cstr_err| io::Errno::INVAL)?)
+}