From 6ab1f75770481d867ee10dbe5a1cfa912424ae2a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Agust=C3=ADn=20Borgna?=
 <121866228+aborgna-q@users.noreply.github.com>
Date: Tue, 3 Sep 2024 15:07:21 +0100
Subject: [PATCH] fix: `std.collections.insert` wrong output order (#1513)

We changed the `Either` type to use the *right* variant to represent
success.

The `insert` operations returns nothing on success, and the element on
error. We had the incorrect order here.
---
 hugr-core/src/std_extensions/collections.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hugr-core/src/std_extensions/collections.rs b/hugr-core/src/std_extensions/collections.rs
index 5900df4ef..270f234b6 100644
--- a/hugr-core/src/std_extensions/collections.rs
+++ b/hugr-core/src/std_extensions/collections.rs
@@ -164,7 +164,7 @@ impl ListOp {
             insert => self
                 .list_polytype(
                     vec![l.clone(), USIZE_T, e.clone()],
-                    vec![l, either_type(Type::UNIT, e).into()],
+                    vec![l, either_type(e, Type::UNIT).into()],
                 )
                 .into(),
             length => self.list_polytype(vec![l], vec![USIZE_T]).into(),