implemented SMT-Lib export SmtSolver interface

src/storm/solver/SmtSolver.cpp

@@ -92,5 +92,10 @@ namespace storm {
             return false;
         }
         
+        std::string SmtSolver::getSmtLibString() const {
+            STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "This solver does not support exporting the assertions in the SMT-LIB format.");
+            return "ERROR";
+        }
+
     } // namespace solver
 } // namespace storm

src/storm/solver/SmtSolver.h

@@ -71,14 +71,9 @@ namespace storm {
             
 			SmtSolver(SmtSolver const& other) = default;
 
-#ifndef WINDOWS
 			SmtSolver(SmtSolver&& other) = default;
-#endif
 			SmtSolver& operator=(SmtSolver const& other) = default;
-
-#ifndef WINDOWS
 			SmtSolver& operator=(SmtSolver&& other) = default;
-#endif
    
 			/*!
              * Pushes a backtracking point on the solver's stack. A following call to pop() deletes exactly those
@@ -153,9 +148,7 @@ namespace storm {
              * @return Sat if the conjunction of the asserted expressions together with the provided assumptions is
              * satisfiable, Unsat if it is unsatisfiable and Unknown if the solver could not determine satisfiability.
 			 */
-#ifndef WINDOWS
 			virtual CheckResult checkWithAssumptions(std::initializer_list<storm::expressions::Expression> const& assumptions) = 0;
-#endif
    
 			/*!
              * If the last call to check() or checkWithAssumptions() returned Sat, this method retrieves a model that
@@ -292,6 +285,13 @@ namespace storm {
              */
             virtual bool unsetTimeout();
             
+			/*!
+			 * If supported by the solver, this function returns the current assertions in the SMT-LIB format.
+			 *
+			 * @return the current assertions in the SMT-LIB format.
+			 */
+			virtual std::string getSmtLibString() const;
+			
         private:
             // The manager responsible for the expressions that interact with this solver.
             storm::expressions::ExpressionManager& manager;

src/storm/solver/Z3SmtSolver.cpp

@@ -361,5 +361,14 @@ namespace storm {
 #endif
         }
 		
+		std::string Z3SmtSolver::getSmtLibString() const {
+#ifdef STORM_HAVE_Z3
+			return solver->to_smt2();
+#else
+            STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "Storm is compiled without Z3 support.");
+#endif
+		}
+
+
 	}
 }

src/storm/solver/Z3SmtSolver.h

@@ -71,6 +71,8 @@ namespace storm {
             
             virtual bool unsetTimeout() override;
 			
+			virtual std::string getSmtLibString() const override;
+            
 		private:
 #ifdef STORM_HAVE_Z3
             /*!