he current solution, build delta assigment representing possible extensions to the current solution and validate them with filters. The tricky bit comes from using the assignment and filter APIs in a way which avoids the lazy creation of internal hash_maps between variables and indices. Generic filter-based decision builder using an <a class="el" href="classoperations__research_1_1IntVarFilteredHeuristic.html" title="Generic filter-based heuristic applied to IntVars.">IntVarFilteredHeuristic</a>. when the c