Use only where appropriate

1 files changed, 10 insertions, 0 deletions

diff --git a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
index fcc13d2..3cdb031 100644
--- a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
+++ b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
@@ -211,4 +211,14 @@ public class ExtraIterables {
             return value;
         }
     }
+
+    public static <T> T only(Iterable<T> iterable, Supplier<RuntimeException> orElse) {
+        Iterator<T> iterator = iterable.iterator();
+        T value = iterator.next();
+        if (iterator.hasNext()) {
+            throw orElse.get();
+        } else {
+            return value;
+        }
+    }
 }