core: Add Clone trait

Author: brson

src/libcore/clone.rs

@@ -0,0 +1,10 @@
+/**
+Clonable types are copied with the clone method
+*/
+pub trait Clone {
+    fn clone(&self) -> self;
+}
+
+impl (): Clone {
+    fn clone(&self) -> () { () }
+}

src/libcore/core.rc

@@ -156,6 +156,7 @@ pub mod to_str;
 pub mod to_bytes;
 pub mod from_str;
 pub mod util;
+pub mod clone;
 
 // Data structure modules
 

src/libcore/core.rs

@@ -48,6 +48,10 @@ pub use coreops::ops::{BitXor};
 #[cfg(test)]
 pub use coreops::ops::{Shl, Shr, Index};
 
+#[cfg(notest)]
+pub use clone::Clone;
+#[cfg(test)]
+pub use coreops::clone::Clone;
 
 // Export the log levels as global constants. Higher levels mean
 // more-verbosity. Error is the bottom level, default logging level is

src/libcore/private.rs

@@ -509,12 +509,14 @@ pub fn exclusive<T:Send >(user_data: T) -> Exclusive<T> {
     Exclusive { x: unsafe { shared_mutable_state(move data) } }
 }
 
-impl<T: Send> Exclusive<T> {
+impl<T: Send> Exclusive<T>: Clone {
     // Duplicate an exclusive ARC, as std::arc::clone.
-    fn clone() -> Exclusive<T> {
+    fn clone(&self) -> Exclusive<T> {
         Exclusive { x: unsafe { clone_shared_mutable_state(&self.x) } }
     }
+}
 
+impl<T: Send> Exclusive<T> {
     // Exactly like std::arc::mutex_arc,access(), but with the little_lock
     // instead of a proper mutex. Same reason for being unsafe.
     //

src/libstd/arc.rs

@@ -103,6 +103,12 @@ fn unwrap<T: Const Send>(rc: ARC<T>) -> T {
     unsafe { unwrap_shared_mutable_state(move x) }
 }
 
+impl<T: Const Send> ARC<T>: Clone {
+    fn clone(&self) -> ARC<T> {
+        clone(self)
+    }
+}
+
 /****************************************************************************
  * Mutex protected ARC (unsafe)
  ****************************************************************************/
@@ -128,13 +134,16 @@ pub fn mutex_arc_with_condvars<T: Send>(user_data: T,
     MutexARC { x: unsafe { shared_mutable_state(move data) } }
 }
 
-impl<T: Send> &MutexARC<T> {
+impl<T: Send> MutexARC<T>: Clone {
     /// Duplicate a mutex-protected ARC, as arc::clone.
-    fn clone() -> MutexARC<T> {
+    fn clone(&self) -> MutexARC<T> {
         // NB: Cloning the underlying mutex is not necessary. Its reference
         // count would be exactly the same as the shared state's.
         MutexARC { x: unsafe { clone_shared_mutable_state(&self.x) } }
     }
+}
+
+impl<T: Send> &MutexARC<T> {
 
     /**
      * Access the underlying mutable data with mutual exclusion from other
@@ -265,13 +274,16 @@ pub fn rw_arc_with_condvars<T: Const Send>(user_data: T,
     RWARC { x: unsafe { shared_mutable_state(move data) }, cant_nest: () }
 }
 
-impl<T: Const Send> &RWARC<T> {
+impl<T: Const Send> RWARC<T> {
     /// Duplicate a rwlock-protected ARC, as arc::clone.
-    fn clone() -> RWARC<T> {
+    fn clone(&self) -> RWARC<T> {
         RWARC { x: unsafe { clone_shared_mutable_state(&self.x) },
                 cant_nest: () }
     }
 
+}
+
+impl<T: Const Send> &RWARC<T> {
     /**
      * Access the underlying data mutably. Locks the rwlock in write mode;
      * other readers and writers will block.

src/libstd/bitv.rs

@@ -290,22 +290,6 @@ impl Bitv {
     #[inline(always)]
     fn assign(v: &Bitv) -> bool { self.do_op(Assign, v) }
 
-    /// Makes a copy of a bitvector
-    #[inline(always)]
-    fn clone() -> ~Bitv {
-        ~match self.rep {
-          Small(ref b) => {
-            Bitv{nbits: self.nbits, rep: Small(~SmallBitv{bits: b.bits})}
-          }
-          Big(ref b) => {
-            let st = to_mut(from_elem(self.nbits / uint_bits + 1, 0));
-            let len = st.len();
-            for uint::range(0, len) |i| { st[i] = b.storage[i]; };
-            Bitv{nbits: self.nbits, rep: Big(~BigBitv{storage: move st})}
-          }
-        }
-    }
-
     /// Retrieve the value at index `i`
     #[inline(always)]
     pure fn get(i: uint) -> bool {
@@ -512,6 +496,25 @@ impl Bitv {
 
 }
 
+impl Bitv: Clone {
+    /// Makes a copy of a bitvector
+    #[inline(always)]
+    fn clone(&self) -> Bitv {
+        match self.rep {
+          Small(ref b) => {
+            Bitv{nbits: self.nbits, rep: Small(~SmallBitv{bits: b.bits})}
+          }
+          Big(ref b) => {
+            let st = to_mut(from_elem(self.nbits / uint_bits + 1, 0));
+            let len = st.len();
+            for uint::range(0, len) |i| { st[i] = b.storage[i]; };
+            Bitv{nbits: self.nbits, rep: Big(~BigBitv{storage: move st})}
+          }
+        }
+    }
+
+}
+
 /**
  * Transform a byte-vector into a bitv. Each byte becomes 8 bits,
  * with the most significant bits of each byte coming first. Each

src/libstd/sync.rs

@@ -358,10 +358,14 @@ fn semaphore(count: int) -> Semaphore {
     Semaphore { sem: new_sem(count, ()) }
 }
 
-impl &Semaphore {
+impl Semaphore: Clone {
     /// Create a new handle to the semaphore.
-    fn clone() -> Semaphore { Semaphore { sem: Sem((*self.sem).clone()) } }
+    fn clone(&self) -> Semaphore {
+        Semaphore { sem: Sem((*self.sem).clone()) }
+    }
+}
 
+impl &Semaphore {
     /**
      * Acquire a resource represented by the semaphore. Blocks if necessary
      * until resource(s) become available.
@@ -404,10 +408,12 @@ pub fn mutex_with_condvars(num_condvars: uint) -> Mutex {
     Mutex { sem: new_sem_and_signal(1, num_condvars) }
 }
 
-impl &Mutex {
+impl Mutex: Clone {
     /// Create a new handle to the mutex.
-    fn clone() -> Mutex { Mutex { sem: Sem((*self.sem).clone()) } }
+    fn clone(&self) -> Mutex { Mutex { sem: Sem((*self.sem).clone()) } }
+}
 
+impl &Mutex {
     /// Run a function with ownership of the mutex.
     fn lock<U>(blk: fn() -> U) -> U { (&self.sem).access(blk) }