Fix #645 related to linking of the library when non-static Generator objects exist

Author: Luca Geretti

CHANGELOG.md

@@ -27,7 +27,8 @@ Legenda for the issue kind:
 - [#639](https://github.com/ariadne-cps/ariadne/issues/639) (C) Use a finer (3/4) refinement strategy for the step size when computing a flow step based on an accuracy threshold
 - [#616](https://github.com/ariadne-cps/ariadne/issues/616) (F) Fix behavior of unary symbolic expression predicates
 - [#620](https://github.com/ariadne-cps/ariadne/issues/620) (F) EulerBounder did not reset the bounding domain between refinements to the step size
-- [#631](https://github.com/ariadne-cps/ariadne/issues/631) (F) Conditional disabling of graphics in absence of both Cairo and Gnuplot was incorrect  
+- [#631](https://github.com/ariadne-cps/ariadne/issues/631) (F) Conditional disabling of graphics in absence of both Cairo and Gnuplot was incorrect
+- [#645](https://github.com/ariadne-cps/ariadne/issues/645) (F) Use only static const Generator objects, addressing linking issue for the whole library
 - [#623](https://github.com/ariadne-cps/ariadne/issues/620) (R) Simplify IntegratorInterface with only one flow step, removing flow/flow_to and hiding flow_bounds
 
 ### 2.3

source/dynamics/differential_inclusion_evolver.hpp

@@ -53,9 +53,9 @@ struct StepSize : public Attribute<StepSizeType> { };
 struct NumberOfStepsBetweenSimplifications : public Attribute<Nat> { };
 struct NumberOfVariablesToKeep : public Attribute<Nat> { };
 
-Generator<StepSize> step_size;
-Generator<NumberOfStepsBetweenSimplifications> number_of_steps_between_simplifications;
-Generator<NumberOfVariablesToKeep> number_of_variables_to_keep;
+static const Generator<StepSize> step_size = Generator<StepSize>();
+static const Generator<NumberOfStepsBetweenSimplifications> number_of_steps_between_simplifications = Generator<NumberOfStepsBetweenSimplifications>();
+static const Generator<NumberOfVariablesToKeep> number_of_variables_to_keep = Generator<NumberOfVariablesToKeep>();
 
 using ThresholdSweeperDP = ThresholdSweeper<FloatDP>;
 using GradedSweeperDP = GradedSweeper<FloatDP>;