identifiers: Add Arc, Rc conversions to ServerName, DeviceId and KeyName

crates/ruma-identifiers/src/macros.rs

@@ -236,6 +236,20 @@ macro_rules! opaque_identifier {
             }
         }
 
+        impl From<&$id> for std::rc::Rc<$id> {
+            fn from(s: &$id) -> std::rc::Rc<$id> {
+                let rc = std::rc::Rc::<str>::from(s.as_str());
+                unsafe { std::rc::Rc::from_raw(std::rc::Rc::into_raw(rc) as *const $id) }
+            }
+        }
+
+        impl From<&$id> for std::sync::Arc<$id> {
+            fn from(s: &$id) -> std::sync::Arc<$id> {
+                let arc = std::sync::Arc::<str>::from(s.as_str());
+                unsafe { std::sync::Arc::from_raw(std::sync::Arc::into_raw(arc) as *const $id) }
+            }
+        }
+
         impl<'a> From<&'a str> for &'a $id {
             fn from(s: &'a str) -> Self {
                 $id::from_borrowed(s)

crates/ruma-identifiers/src/server_name.rs

@@ -1,6 +1,5 @@
 //! Matrix-spec compliant server names.
-
-use std::{convert::TryFrom, fmt, mem, str::FromStr};
+use std::{convert::TryFrom, fmt, mem, rc::Rc, str::FromStr, sync::Arc};
 
 use ruma_identifiers_validation::server_name::validate;
 
@@ -115,6 +114,26 @@ impl TryFrom<&str> for Box<ServerName> {
     }
 }
 
+impl TryFrom<&ServerName> for Rc<ServerName> {
+    type Error = crate::Error;
+
+    fn try_from(s: &ServerName) -> Result<Self, Self::Error> {
+        validate(s.as_str())?;
+        let rc = Rc::<str>::from(s.as_str());
+        Ok(unsafe { Rc::from_raw(Rc::into_raw(rc) as *const ServerName) })
+    }
+}
+
+impl TryFrom<&ServerName> for Arc<ServerName> {
+    type Error = crate::Error;
+
+    fn try_from(s: &ServerName) -> Result<Self, Self::Error> {
+        validate(s.as_str())?;
+        let arc = Arc::<str>::from(s.as_str());
+        Ok(unsafe { Arc::from_raw(Arc::into_raw(arc) as *const ServerName) })
+    }
+}
+
 impl TryFrom<String> for Box<ServerName> {
     type Error = crate::Error;