Use range-based loop in ApplyConstraints.

ddecal/gain_solvers/SolverBase.cc

@@ -99,16 +99,17 @@ bool SolverBase::ApplyConstraints(
   bool constraints_satisfied = true;
 
   result.results.resize(constraints_.size());
+  auto result_iterator = result.results.begin();
 
-  for (size_t i = 0; i != constraints_.size(); ++i) {
-    Constraint& c = *constraints_[i];
+  for (const std::unique_ptr<Constraint>& c : constraints_) {
     // PrepareIteration() might change Satisfied(), and since we always want
     // to iterate at least once more when a constraint is not yet satisfied,
     // we evaluate Satisfied() before preparing.
-    constraints_satisfied = c.Satisfied() && constraints_satisfied;
-    c.PrepareIteration(has_previously_converged, iteration,
-                       iteration + 1 >= GetMaxIterations());
-    result.results[i] = c.Apply(next_solutions, time, stat_stream);
+    constraints_satisfied = c->Satisfied() && constraints_satisfied;
+    c->PrepareIteration(has_previously_converged, iteration,
+                        iteration + 1 >= GetMaxIterations());
+    *result_iterator = c->Apply(next_solutions, time, stat_stream);
+    ++result_iterator;
   }
 
   // If still not satisfied, at least iteration+1 constrained iterations