rand: deprecate `rng`.

This should be called far less than it is because it does expensive OS
interactions and seeding of the internal RNG, `task_rng` amortises this
cost. The main problem is the name is so short and suggestive.

The direct equivalent is `StdRng::new`, which does precisely the same
thing.

The deprecation will make migrating away from the function easier.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/libextra/tempfile.rs b/src/libextra/tempfile.rs
index 4e4d80ae292..905541604e0 100644
--- a/src/libextra/tempfile.rs
+++ b/src/libextra/tempfile.rs
@@ -12,8 +12,7 @@
 
 
 use std::os;
-use rand::Rng;
-use rand;
+use rand::{task_rng, Rng};
 use std::io;
 use std::io::fs;
 
@@ -35,7 +34,7 @@ impl TempDir {
             return TempDir::new_in(&abs_tmpdir, suffix);
         }
 
-        let mut r = rand::rng();
+        let mut r = task_rng();
         for _ in range(0u, 1000) {
             let p = tmpdir.join(r.gen_ascii_str(16) + suffix);
             match fs::mkdir(&p, io::UserRWX) {