From 89ce86eec09e86285bee5ef24cc1f9e0335f2388 Mon Sep 17 00:00:00 2001
From: Stavros Polymenis <sp@orbitalfox.eu>
Date: Tue, 27 Mar 2018 23:05:34 +0100
Subject: [PATCH] Assert emptiness on both maps instead of raising custom
 exception.
 https://github.com/c-cube/ocaml-containers/pull/211\#pullrequestreview-107483136

---
 src/data/CCBijection.ml | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/data/CCBijection.ml b/src/data/CCBijection.ml
index e3f5dfba..306d28c7 100644
--- a/src/data/CCBijection.ml
+++ b/src/data/CCBijection.ml
@@ -45,9 +45,10 @@ module Make(L : OrderedType)(R : OrderedType) = struct
       right = MapR.empty;
     }
 
-  let is_empty m = match MapL.is_empty m.left, MapR.is_empty m.right with
-    | l, r when l = r -> l
-    | l, r -> raise (Incoherence ("is_empty left: " ^ string_of_bool l ^ ", right: " ^ string_of_bool r))
+  let is_empty m =
+    let res = MapL.is_empty m.left in
+    assert (res = MapR.is_empty m.right);
+    res
 
   let add a b m = {
       left =