Add a unwrap() function to StatusAnd.

This provides an easy way to get the value and check for errors.

src/lib.rs

@@ -90,6 +90,20 @@ impl<T> StatusAnd<T> {
     }
 }
 
+impl<T: core::fmt::Debug> StatusAnd<T> {
+    /// Extract the inner value if there were no errors. If there were errors, panic.
+    pub fn unwrap(self) -> T {
+        if self.state == Status::OK {
+            self.value
+        } else {
+            panic!(
+                "called `StatusAnd::unwrap()` on an error value. Value: {:?}, status: {:?}",
+                self.value, self.status
+            );
+        }
+    }
+}
+
 #[macro_export]
 macro_rules! unpack {
     ($status:ident|=, $e:expr) => {