Make parse errors implement Send and Sync
diff --git a/src/thread.rs b/src/thread.rs
new file mode 100644
index 0000000..2c15912
--- /dev/null
+++ b/src/thread.rs
@@ -0,0 +1,66 @@
+use std::fmt::{self, Debug};
+
+#[cfg(syn_can_use_thread_id)]
+mod imp {
+ use std::thread::{self, ThreadId};
+
+ /// ThreadBound is a Sync-maker and Send-maker that allows accessing a value
+ /// of type T only from the original thread on which the ThreadBound was
+ /// constructed.
+ pub struct ThreadBound<T> {
+ value: T,
+ thread_id: ThreadId,
+ }
+
+ unsafe impl<T> Sync for ThreadBound<T> {}
+
+ // Send bound requires Copy, as otherwise Drop could run in the wrong place.
+ unsafe impl<T: Copy> Send for ThreadBound<T> {}
+
+ impl<T> ThreadBound<T> {
+ pub fn new(value: T) -> Self {
+ ThreadBound {
+ value: value,
+ thread_id: thread::current().id(),
+ }
+ }
+
+ pub fn get(&self) -> Option<&T> {
+ if thread::current().id() == self.thread_id {
+ Some(&self.value)
+ } else {
+ None
+ }
+ }
+ }
+}
+
+#[cfg(not(syn_can_use_thread_id))]
+mod imp {
+ pub struct ThreadBound<T> {
+ value: T,
+ }
+
+ impl<T> ThreadBound<T> {
+ pub fn new(value: T) -> Self {
+ ThreadBound {
+ value: value,
+ }
+ }
+
+ pub fn get(&self) -> Option<&T> {
+ Some(&self.value)
+ }
+ }
+}
+
+pub use self::imp::ThreadBound;
+
+impl<T: Debug> Debug for ThreadBound<T> {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ match self.get() {
+ Some(value) => Debug::fmt(value, formatter),
+ None => formatter.write_str("unknown"),
+ }
+ }
+}