From 070d034de9695f9022567c4d70bcaa6e0a08ccd1 Mon Sep 17 00:00:00 2001
From: Michael Walker <mike@barrucadu.co.uk>
Date: Fri, 19 Dec 2014 06:24:50 +0000
Subject: [PATCH] Implement IO's 'spawn' in terms of other conc primitives

---
 Control/Monad/Conc/Class.hs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Control/Monad/Conc/Class.hs b/Control/Monad/Conc/Class.hs
index a412a1c..7f5b85f 100755
--- a/Control/Monad/Conc/Class.hs
+++ b/Control/Monad/Conc/Class.hs
@@ -35,9 +35,9 @@ class Monad m => ConcFuture future m | m -> future where
 
 instance ConcFuture MVar IO where
   spawn ma = do
-    mvar <- newEmptyMVar
-    void . forkIO $ ma >>= putMVar mvar
-    return mvar
+    cvar <- new
+    fork $ ma >>= put cvar
+    return cvar
 
   get = readMVar