Automated fixes by clang-tidy

Author: github-actions[bot]

ql/termstructures/yield/oisratehelper.cpp

@@ -39,7 +39,7 @@ namespace QuantLib {
         Frequency paymentFrequency,
         Calendar paymentCalendar,
         const Period& forwardStart,
-        const std::variant<Spread, Handle<Quote>> overnightSpread,
+        const std::variant<Spread, Handle<Quote>>& overnightSpread,
         Pillar::Choice pillar,
         Date customPillarDate,
         RateAveraging::Type averagingMethod,
@@ -73,7 +73,7 @@ namespace QuantLib {
         BusinessDayConvention paymentConvention,
         Frequency paymentFrequency,
         Calendar paymentCalendar,
-        const std::variant<Spread, Handle<Quote>> overnightSpread,
+        const std::variant<Spread, Handle<Quote>>& overnightSpread,
         Pillar::Choice pillar,
         Date customPillarDate,
         RateAveraging::Type averagingMethod,
@@ -262,6 +262,6 @@ namespace QuantLib {
                                            const Calendar& fixedCalendar)
     : DatedOISRateHelper(startDate, endDate, fixedRate, overnightIndex, std::move(discount), telescopicValueDates,
                          averagingMethod, paymentLag, paymentConvention, paymentFrequency, paymentCalendar,
-                         std::move(overnightSpread), endOfMonth, fixedPaymentFrequency, fixedCalendar) {}
+                         overnightSpread, endOfMonth, fixedPaymentFrequency, fixedCalendar) {}
 
 }

ql/termstructures/yield/oisratehelper.hpp

@@ -49,7 +49,7 @@ namespace QuantLib {
           Frequency paymentFrequency = Annual,
           Calendar paymentCalendar = Calendar(),
           const Period& forwardStart = 0 * Days,
-          std::variant<Spread, Handle<Quote>> overnightSpread = Spread(0.0),
+          const std::variant<Spread, Handle<Quote>>& overnightSpread = Spread(0.0),
           Pillar::Choice pillar = Pillar::LastRelevantDate,
           Date customPillarDate = Date(),
           RateAveraging::Type averagingMethod = RateAveraging::Compound,
@@ -73,7 +73,7 @@ namespace QuantLib {
           BusinessDayConvention paymentConvention = Following,
           Frequency paymentFrequency = Annual,
           Calendar paymentCalendar = Calendar(),
-          std::variant<Spread, Handle<Quote>> overnightSpread = Spread(0.0),
+          const std::variant<Spread, Handle<Quote>>& overnightSpread = Spread(0.0),
           Pillar::Choice pillar = Pillar::LastRelevantDate,
           Date customPillarDate = Date(),
           RateAveraging::Type averagingMethod = RateAveraging::Compound,