Simplify getting the fixing for an IBOR coupon by first checking if i…

…t has fixed or not

ql/cashflows/iborcoupon.cpp

@@ -114,34 +114,15 @@ namespace QuantLib {
            1) allows to save date/time recalculations, and
            2) takes into account par coupon needs
         */
-        Date today = QuantLib::Settings::instance().evaluationDate();
-
-        if (fixingDate_>today)
-            return iborIndex_->forecastFixing(fixingValueDate_,
-                                              fixingEndDate_,
-                                              spanningTime_);
 
-        if (fixingDate_<today ||
-            QuantLib::Settings::instance().enforcesTodaysHistoricFixings()) {
-            // do not catch exceptions
+        if (hasFixed()) {
             Rate result = index_->pastFixing(fixingDate_);
             QL_REQUIRE(result != Null<Real>(),
                        "Missing " << index_->name() << " fixing for " << fixingDate_);
             return result;
+        } else {
+            return iborIndex_->forecastFixing(fixingValueDate_, fixingEndDate_, spanningTime_);
         }
-
-        try {
-            Rate result = index_->pastFixing(fixingDate_);
-            if (result!=Null<Real>())
-                return result;
-            else
-                ;   // fall through and forecast
-        } catch (Error&) {
-                ;   // fall through and forecast
-        }
-        return iborIndex_->forecastFixing(fixingValueDate_,
-                                          fixingEndDate_,
-                                          spanningTime_);
     }
 
     void IborCoupon::setPricer(const ext::shared_ptr<FloatingRateCouponPricer>& pricer) {