implemented creation of round expression.

src/storm/storage/expressions/Expression.cpp

@@ -414,6 +414,11 @@ namespace storm {
             STORM_LOG_THROW(first.hasNumericalType(), storm::exceptions::InvalidTypeException, "Operator 'ceil' requires numerical operand.");
             return Expression(std::shared_ptr<BaseExpression>(new UnaryNumericalFunctionExpression(first.getBaseExpression().getManager(), first.getType().floorCeil(), first.getBaseExpressionPointer(), UnaryNumericalFunctionExpression::OperatorType::Ceil)));
         }
+        
+        Expression round(Expression const& first) {
+            STORM_LOG_THROW(first.hasNumericalType(), storm::exceptions::InvalidTypeException, "Operator 'round' requires numerical operand.");
+            return floor(first + first.getManager().rational(0.5));
+        }
 
         Expression abs(Expression const& first) {
             STORM_LOG_THROW(first.hasNumericalType(), storm::exceptions::InvalidTypeException, "Abs is only defined for numerical operands");

src/storm/storage/expressions/Expression.h

@@ -56,6 +56,7 @@ namespace storm {
             friend Expression sign(Expression const& first);
             friend Expression floor(Expression const& first);
             friend Expression ceil(Expression const& first);
+            friend Expression round(Expression const& first);
             friend Expression minimum(Expression const& first, Expression const& second);
             friend Expression maximum(Expression const& first, Expression const& second);
 
@@ -434,6 +435,7 @@ namespace storm {
         Expression sign(Expression const& first);
         Expression floor(Expression const& first);
         Expression ceil(Expression const& first);
+        Expression round(Expression const& first);
         Expression minimum(Expression const& first, Expression const& second);
         Expression maximum(Expression const& first, Expression const& second);
         Expression disjunction(std::vector<storm::expressions::Expression> const& expressions);