fix tuple assignment when rhs is a conditional

zokrates_core/src/semantics.rs

@@ -2500,6 +2500,9 @@ impl<'ast, T: Field> Checker<'ast, T> {
                             (TypedExpression::Struct(consequence), TypedExpression::Struct(alternative)) => {
                                 Ok(StructExpression::conditional(condition, consequence, alternative, kind).into())
                             },
+                            (TypedExpression::Tuple(consequence), TypedExpression::Tuple(alternative)) => {
+                                Ok(TupleExpression::conditional(condition, consequence, alternative, kind).into())
+                            },
                             (TypedExpression::Uint(consequence), TypedExpression::Uint(alternative)) => {
                                 Ok(UExpression::conditional(condition, consequence, alternative, kind).into())
                             },

zokrates_core_test/tests/tests/tuples/conditional.json

@@ -0,0 +1,26 @@
+{
+    "entry_point": "./tests/tests/tuples/conditional.zok",
+    "curves": ["Bn128"],
+    "tests": [
+        {
+            "input": {
+                "values": [true]
+            },
+            "output": {
+                "Ok": {
+                    "values": [["1", "2"]]
+                }
+            }
+        },
+        {
+            "input": {
+                "values": [false]
+            },
+            "output": {
+                "Ok": {
+                    "values": [["2", "1"]]
+                }
+            }
+        }
+    ]
+}

zokrates_core_test/tests/tests/tuples/conditional.zok

@@ -0,0 +1,3 @@
+def main(bool flag) -> ((field, field)):
+    (field, field) a = if flag then (1f, 2f) else (2f, 1f) fi
+    return a