Ref T231, Ref T238 maxValue for PQs

Remark: max() as function name caused compile errors

src/blackmisc/pq/length.h

@@ -19,7 +19,6 @@ namespace BlackMisc
 {
     namespace PhysicalQuantities
     {
-
         //! Physical unit length (length)
         class BLACKMISC_EXPORT CLength : public CPhysicalQuantity<CLengthUnit, CLength>
         {
@@ -33,7 +32,6 @@ namespace BlackMisc
             //! \copydoc CPhysicalQuantity(const QString &unitString)
             CLength(const QString &unitString) : CPhysicalQuantity(unitString) {}
         };
-
     } // ns
 } // ns
 

src/blackmisc/pq/physicalquantity.cpp

@@ -357,6 +357,22 @@ namespace BlackMisc
             return this->valueRoundedWithUnit(this->getUnit(), -1, i18n);
         }
 
+        template<class MU, class PQ>
+        const PQ &CPhysicalQuantity<MU, PQ>::maxValue(const PQ &pq1, const PQ &pq2)
+        {
+            if (pq1.isNull()) { return pq2; }
+            if (pq2.isNull()) { return pq1; }
+            return pq1 > pq2 ? pq1 : pq2;
+        }
+
+        template<class MU, class PQ>
+        const PQ &CPhysicalQuantity<MU, PQ>::minValue(const PQ &pq1, const PQ &pq2)
+        {
+            if (pq1.isNull()) { return pq2; }
+            if (pq2.isNull()) { return pq1; }
+            return pq1 < pq2 ? pq1 : pq2;
+        }
+
         template <class MU, class PQ>
         uint CPhysicalQuantity<MU, PQ>::getValueHash() const
         {

src/blackmisc/pq/physicalquantity.h

@@ -234,6 +234,12 @@ namespace BlackMisc
             //! \copydoc BlackMisc::Mixin::String::toQString
             QString convertToQString(bool i18n = false) const;
 
+            //! Maximum of 2 quantities
+            static const PQ &maxValue(const PQ &pq1, const PQ &pq2);
+
+            //! Minimum of 2 quantities
+            static const PQ &minValue(const PQ &pq1, const PQ &pq2);
+
         protected:
             //! Constructor with double
             CPhysicalQuantity(double value, MU unit);