From abdf9078ef13154374f75fa0bb9c28a15c9286bd Mon Sep 17 00:00:00 2001
From: Daan Sprenkels <dsprenkels@gmail.com>
Date: Sun, 3 Apr 2016 22:29:40 +0200
Subject: [PATCH] make RustBox type Send, but still not Sync

The RustBox type is not thread safe, in the sense that multiple
threads may never alter the mutable state of a shared RustBox
at the same time, so it should not be marked Sync.
However, a RustBox type *can* safely be sent between threads so
it *should* be marked Send.

This commit makes it possible to wrap a RustBox struct inside
a Mutex type, so that it can still be used when the programmer
decides to do the syncronization theirself.
---
 src/rustbox.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/rustbox.rs b/src/rustbox.rs
index 464d207..9cad75a 100644
--- a/src/rustbox.rs
+++ b/src/rustbox.rs
@@ -5,6 +5,7 @@ extern crate termbox_sys as termbox;
 
 pub use self::style::{Style, RB_BOLD, RB_UNDERLINE, RB_REVERSE, RB_NORMAL};
 
+use std::cell::UnsafeCell;
 use std::error::Error;
 use std::fmt;
 use std::io;
@@ -221,7 +222,7 @@ pub struct RustBox {
     // top-down order. Otherwise it will not properly protect the above fields.
     _running: running::RunningGuard,
     // Termbox is not thread safe. See #39.
-    _phantom: PhantomData<*mut ()>,
+    _phantom: PhantomData<UnsafeCell<()>>,
 }
 
 #[derive(Clone, Copy,Debug)]