Replace ad-hoc copy_memory function with [T]::copy_from_slice

Author: SimonSapin

src/atom.rs

@@ -23,7 +23,6 @@ use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;
 use std::mem;
 use std::ops;
-use std::ptr;
 use std::slice;
 use std::str;
 use std::sync::Mutex;
@@ -314,7 +313,7 @@ impl<'a, Static: StaticAtomSet> From<Cow<'a, str>> for Atom<Static> {
             let len = string_to_add.len();
             if len <= MAX_INLINE_LEN {
                 let mut buf: [u8; 7] = [0; 7];
-                copy_memory(string_to_add.as_bytes(), &mut buf);
+                buf[..len].copy_from_slice(string_to_add.as_bytes());
                 Inline(len as u8, buf)
             } else {
                 Dynamic(STRING_CACHE.lock().unwrap().add(string_to_add, hash) as *mut ())
@@ -571,7 +570,7 @@ impl UnpackedAtom {
                 let mut data: u64 = (INLINE_TAG as u64) | ((len as u64) << 4);
                 {
                     let dest = inline_atom_slice_mut(&mut data);
-                    copy_memory(&buf[..], dest);
+                    dest.copy_from_slice(&buf)
                 }
                 data
             }
@@ -590,7 +589,7 @@ impl UnpackedAtom {
                 debug_assert!(len <= MAX_INLINE_LEN);
                 let mut buf: [u8; 7] = [0; 7];
                 let src = inline_atom_slice(&data);
-                copy_memory(src, &mut buf[..]);
+                buf.copy_from_slice(src);
                 Inline(len as u8, buf)
             },
             _ => debug_unreachable!(),
@@ -623,21 +622,6 @@ unsafe fn inline_orig_bytes<'a>(data: &'a u64) -> &'a [u8] {
     }
 }
 
-
-/// Copy of std::slice::bytes::copy_memory, which is unstable.
-#[inline]
-fn copy_memory(src: &[u8], dst: &mut [u8]) {
-    let len_src = src.len();
-    assert!(dst.len() >= len_src);
-    // `dst` is unaliasable, so we know statically it doesn't overlap
-    // with `src`.
-    unsafe {
-        ptr::copy_nonoverlapping(src.as_ptr(),
-                                 dst.as_mut_ptr(),
-                                 len_src);
-    }
-}
-
 #[cfg(test)]
 #[macro_use]
 mod tests {