about summary refs log tree commit diff
path: root/src/libcore
diff options
context:
space:
mode:
Diffstat (limited to 'src/libcore')
-rw-r--r--src/libcore/option.rs14
1 files changed, 14 insertions, 0 deletions
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index b91a8cebded..45ccf657dbd 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -233,6 +233,20 @@ impl<T> Option<T> {
     // Getting to contained values
     /////////////////////////////////////////////////////////////////////////
 
+    /// Unwraps an option, yielding the content of a `Some`
+    ///
+    /// # Failure
+    ///
+    /// Fails if the value is a `None` with a custom failure message provided by
+    /// `msg`.
+    #[inline]
+    pub fn expect(self, msg: &str) -> T {
+        match self {
+            Some(val) => val,
+            None => fail!(msg),
+        }
+    }
+
     /// Moves a value out of an option type and returns it, consuming the `Option`.
     ///
     /// # Failure