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>`

4 files changed, 96 insertions, 0 deletions

diff --git a/src/libstd/sys/redox/os_str.rs b/src/libstd/sys/redox/os_str.rs
index c54286353a9..5c40d42fa0a 100644
--- a/src/libstd/sys/redox/os_str.rs
+++ b/src/libstd/sys/redox/os_str.rs
@@ -15,6 +15,8 @@ use borrow::Cow;
 use fmt;
 use str;
 use mem;
+use rc::Rc;
+use sync::Arc;
 use sys_common::{AsInner, IntoInner};
 use std_unicode::lossy::Utf8Lossy;
 
@@ -123,6 +125,16 @@ impl Buf {
         let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
         Buf { inner: inner.into_vec() }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        self.as_slice().into_arc()
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        self.as_slice().into_rc()
+    }
 }
 
 impl Slice {
@@ -156,4 +168,16 @@ impl Slice {
         let boxed: Box<[u8]> = Default::default();
         unsafe { mem::transmute(boxed) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        let arc: Arc<[u8]> = Arc::from(&self.inner);
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        let rc: Rc<[u8]> = Rc::from(&self.inner);
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
+    }
 }
diff --git a/src/libstd/sys/unix/os_str.rs b/src/libstd/sys/unix/os_str.rs
index 777db17e3e1..a27e76a0e3b 100644
--- a/src/libstd/sys/unix/os_str.rs
+++ b/src/libstd/sys/unix/os_str.rs
@@ -15,6 +15,8 @@ use borrow::Cow;
 use fmt;
 use str;
 use mem;
+use rc::Rc;
+use sync::Arc;
 use sys_common::{AsInner, IntoInner};
 use std_unicode::lossy::Utf8Lossy;
 
@@ -123,6 +125,16 @@ impl Buf {
         let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
         Buf { inner: inner.into_vec() }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        self.as_slice().into_arc()
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        self.as_slice().into_rc()
+    }
 }
 
 impl Slice {
@@ -156,4 +168,16 @@ impl Slice {
         let boxed: Box<[u8]> = Default::default();
         unsafe { mem::transmute(boxed) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        let arc: Arc<[u8]> = Arc::from(&self.inner);
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        let rc: Rc<[u8]> = Rc::from(&self.inner);
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
+    }
 }
diff --git a/src/libstd/sys/wasm/os_str.rs b/src/libstd/sys/wasm/os_str.rs
index c5908a7a8dc..0e64b5bc6b8 100644
--- a/src/libstd/sys/wasm/os_str.rs
+++ b/src/libstd/sys/wasm/os_str.rs
@@ -15,6 +15,8 @@ use borrow::Cow;
 use fmt;
 use str;
 use mem;
+use rc::Rc;
+use sync::Arc;
 use sys_common::{AsInner, IntoInner};
 use std_unicode::lossy::Utf8Lossy;
 
@@ -123,6 +125,16 @@ impl Buf {
         let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
         Buf { inner: inner.into_vec() }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        self.as_slice().into_arc()
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        self.as_slice().into_rc()
+    }
 }
 
 impl Slice {
@@ -156,4 +168,16 @@ impl Slice {
         let boxed: Box<[u8]> = Default::default();
         unsafe { mem::transmute(boxed) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        let arc: Arc<[u8]> = Arc::from(&self.inner);
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        let rc: Rc<[u8]> = Rc::from(&self.inner);
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
+    }
 }
diff --git a/src/libstd/sys/windows/os_str.rs b/src/libstd/sys/windows/os_str.rs
index 3eb4582718b..b8d2f7bc53c 100644
--- a/src/libstd/sys/windows/os_str.rs
+++ b/src/libstd/sys/windows/os_str.rs
@@ -15,6 +15,8 @@ use borrow::Cow;
 use fmt;
 use sys_common::wtf8::{Wtf8, Wtf8Buf};
 use mem;
+use rc::Rc;
+use sync::Arc;
 use sys_common::{AsInner, IntoInner};
 
 #[derive(Clone, Hash)]
@@ -115,6 +117,16 @@ impl Buf {
         let inner: Box<Wtf8> = unsafe { mem::transmute(boxed) };
         Buf { inner: Wtf8Buf::from_box(inner) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        self.as_slice().into_arc()
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        self.as_slice().into_rc()
+    }
 }
 
 impl Slice {
@@ -144,4 +156,16 @@ impl Slice {
     pub fn empty_box() -> Box<Slice> {
         unsafe { mem::transmute(Wtf8::empty_box()) }
     }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        let arc = self.inner.into_arc();
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        let rc = self.inner.into_rc();
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
+    }
 }