defer macro

1 files changed, 16 insertions, 0 deletions

diff --git a/src/defer.rs b/src/defer.rs
new file mode 100644
index 0000000..362c7d1
--- /dev/null
+++ b/src/defer.rs
@@ -0,0 +1,16 @@
+pub struct Defer<T: FnOnce()>(pub Option<T>);
+
+impl<T: FnOnce()> Drop for Defer<T> {
+    fn drop(&mut self) {
+        if let Some(f) = self.0.take() {
+            f();
+        }
+    }
+}
+
+#[macro_export]
+macro_rules! defer {
+    ($($x:tt)*) => {
+        let _defer = crate::defer::Defer(Some(move || {$($x)*}));
+    };
+}