Auto merge of #45990 - murarth:rc-from-strs, r=alexcrichton

Implement `Rc`/`Arc` conversions for string-like types

Provides the following conversion implementations:

* `From<`{`CString`,`&CStr`}`>` for {`Arc`,`Rc`}`<CStr>`
* `From<`{`OsString`,`&OsStr`}`>` for {`Arc`,`Rc`}`<OsStr>`
* `From<`{`PathBuf`,`&Path`}`>` for {`Arc`,`Rc`}`<Path>`

Closes #45008

1 files changed, 14 insertions, 0 deletions

diff --git a/src/libstd/sys_common/wtf8.rs b/src/libstd/sys_common/wtf8.rs
index b89a73cd28a..e212b5006f2 100644
--- a/src/libstd/sys_common/wtf8.rs
+++ b/src/libstd/sys_common/wtf8.rs
@@ -35,8 +35,10 @@ use hash::{Hash, Hasher};
 use iter::FromIterator;
 use mem;
 use ops;
+use rc::Rc;
 use slice;
 use str;
+use sync::Arc;
 use sys_common::AsInner;
 
 const UTF8_REPLACEMENT_CHARACTER: &'static str = "\u{FFFD}";
@@ -641,6 +643,18 @@ impl Wtf8 {
         let boxed: Box<[u8]> = Default::default();
         unsafe { mem::transmute(boxed) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Wtf8> {
+        let arc: Arc<[u8]> = Arc::from(&self.bytes);
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Wtf8) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Wtf8> {
+        let rc: Rc<[u8]> = Rc::from(&self.bytes);
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Wtf8) }
+    }
 }