Fixed seg fault when building model valuations

src/storm/builder/ExplicitModelBuilder.h

@@ -79,7 +79,7 @@ namespace storm {
                 
                 // A flag that indicates whether or not to store the state information after successfully building the
                 // model. If it is to be preserved, it can be retrieved via the appropriate methods after a successful
-                // call to <code>translateProgram</code>.
+                // call to <code>build</code>.
                 bool buildStateValuations;
             };
             

src/storm/storage/expressions/SimpleValuation.cpp

@@ -19,7 +19,7 @@ namespace storm {
             // Intentionally left empty.
         }
         
-        SimpleValuation::SimpleValuation(SimpleValuation const& other) : Valuation(other.getManager().getSharedPointer()) {
+        SimpleValuation::SimpleValuation(SimpleValuation const& other) : Valuation(other.getManagerAsSharedPtr()) {
             if (this != &other) {
                 booleanValues = other.booleanValues;
                 integerValues = other.integerValues;
@@ -29,7 +29,7 @@ namespace storm {
                 
         SimpleValuation& SimpleValuation::operator=(SimpleValuation const& other) {
             if (this != &other) {
-                this->setManager(other.getManager().getSharedPointer());
+                this->setManager(other.getManagerAsSharedPtr());
                 booleanValues = other.booleanValues;
                 integerValues = other.integerValues;
                 rationalValues = other.rationalValues;
@@ -37,7 +37,7 @@ namespace storm {
             return *this;
         }
         
-        SimpleValuation::SimpleValuation(SimpleValuation&& other) : Valuation(other.getManager().getSharedPointer()) {
+        SimpleValuation::SimpleValuation(SimpleValuation&& other) : Valuation(other.getManagerAsSharedPtr()) {
             if (this != &other) {
                 booleanValues = std::move(other.booleanValues);
                 integerValues = std::move(other.integerValues);
@@ -47,7 +47,7 @@ namespace storm {
         
         SimpleValuation& SimpleValuation::operator=(SimpleValuation&& other) {
             if (this != &other) {
-                this->setManager(other.getManager().getSharedPointer());
+                this->setManager(other.getManagerAsSharedPtr());
                 booleanValues = std::move(other.booleanValues);
                 integerValues = std::move(other.integerValues);
                 rationalValues = std::move(other.rationalValues);

src/storm/storage/expressions/Valuation.cpp

@@ -15,6 +15,10 @@ namespace storm {
             return *manager;
         }
         
+        std::shared_ptr<ExpressionManager const> const& Valuation::getManagerAsSharedPtr() const {
+            return manager;
+        }
+        
         void Valuation::setManager(std::shared_ptr<ExpressionManager const> const& manager) {
             this->manager = manager;
         }

src/storm/storage/expressions/Valuation.h

@@ -101,6 +101,14 @@ namespace storm {
             ExpressionManager const& getManager() const;
 
         protected:
+                        
+            /*!
+             * Retrieves the manager responsible for the variables of this valuation.
+             *
+             * @return The manager.
+             */
+            std::shared_ptr<ExpressionManager const> const& getManagerAsSharedPtr() const;
+            
             /*!
              * Sets the manager responsible for the variables in this valuation.
              *