X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fucioption.cpp;h=1504f64ec41c8d88c3bfe40283a61907bb2af1bd;hp=2eb7d1c62c6a0c9480a4ebf75c2e0adef1f6c277;hb=e81d0d08c398f9a3708d9dadbb75d9b3feb5efaf;hpb=72c7595f8ac72c7831ee319b8b0bc46404c5fc27

diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index 2eb7d1c6..1504f64e 100644
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -68,7 +68,7 @@ namespace {
     Option(bool defaultValue, OptionType = CHECK);
     Option(int defaultValue, int minValue, int maxValue);
 
-    bool operator<(const Option& o) { return this->idx < o.idx; }
+    bool operator<(const Option& o) const { return this->idx < o.idx; }
   };
 
   typedef std::map<std::string, Option> Options;