From c9bb33db0fde70d31eff6b175b4db8289182ef8d Mon Sep 17 00:00:00 2001
From: Frank Dellaert <dellaert@gmail.com>
Date: Sun, 5 Feb 2023 16:01:07 -0800
Subject: [PATCH] Fix parser

---
 gtsam/discrete/SignatureParser.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gtsam/discrete/SignatureParser.cpp b/gtsam/discrete/SignatureParser.cpp
index 2081e1ee1..8e0221f01 100644
--- a/gtsam/discrete/SignatureParser.cpp
+++ b/gtsam/discrete/SignatureParser.cpp
@@ -34,7 +34,7 @@ std::optional<Row> static ParseConditional(const std::string& token) {
       row.push_back(std::stod(s));
     }
     // if we ended with a '/' then return false
-    if (token.back() == '/') return false;
+    if (token.back() == '/') return std::nullopt;
   } catch (...) {
     return std::nullopt;
   }