---

yaml
---
r: 82247
b: refs/heads/master
c: 649c175
h: refs/heads/master
i:
  82245: 7968cd9
  82243: 78d88e3
  82239: 2e35ff4
v: v3

Author: huonw

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 38732c4b5cf778cb1b441bfc4290b3e3524b80c2
+refs/heads/master: 649c1759e8b56f0ac31dd31e46eae81b7ffd1e2c
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 6c08cc2db4f98e9f07ae7d50338396c4123c2f0a
 refs/heads/try: 70152ff55722878cde684ee6462c14c65f2c4729

trunk/src/libstd/rand/reader.rs

@@ -47,13 +47,17 @@ impl<R: Reader> ReaderRng<R> {
 
 impl<R: Reader> Rng for ReaderRng<R> {
     fn next_u32(&mut self) -> u32 {
+        // This is designed for speed: reading a LE integer on a LE
+        // platform just involves blitting the bytes into the memory
+        // of the u32, similarly for BE on BE; avoiding byteswapping.
         if cfg!(target_endian="little") {
             self.reader.read_le_u32_()
         } else {
             self.reader.read_be_u32_()
         }
     }
     fn next_u64(&mut self) -> u64 {
+        // see above for explanation.
         if cfg!(target_endian="little") {
             self.reader.read_le_u64_()
         } else {