message: Add noexcept and fix minor issues
diff: @@ -105,20 +105,18 @@ public:
  *
  * @return The maximum number of iterations.
  */
  - int get_max_iters() const { return max_iters_; }
  -
  + int get_max_iters() const noexcept { return max_iters_; }
  /**
  * Gets the relative residual goal of the solver.
  *
  * @return The relative residual goal.
  */
  - remove_complex<value_type> get_rel_residual_goal() const
  + remove_complex<value_type> get_rel_residual_goal() const noexcept
  {
  return rel_residual_goal_;
  }
  -
  private:
  Fcg(std::shared_ptr<const Executor> exec, int max_iters,
  remove_complex<value_type> rel_residual_goal,
  @@ -148,21 +146,21 @@ private:
  /**
  * The FcgFactory class is derived from the LinOpFactory class and is
  - * used to generate the FCG factory.
  + * used to generate the FCG solver.
  */
  template <typename ValueType = default_precision>
  class FcgFactory : public LinOpFactory {
  public:
  using value_type = ValueType;
  /**
  - * Creates the FCG solver.
  + * Creates the FCG factory.
  *
  * @param exec The executor on which the FCG solver is to be created.
  * @param max_iters The maximum number of iterations to be pursued.
  * @param rel_residual_goal The relative residual required for
  * convergence.
  *
  - * @return The newly created FCG solver.
  + * @return The newly created FCG factory.
  */
  static std::unique_ptr<FcgFactory> create(
  std::shared_ptr<const Executor> exec, int max_iters,
  @@ -180,14 +178,14 @@ public:
  *
  * @return The maximum number of iterations.
  */
  - int get_max_iters() const { return max_iters_; }
  + int get_max_iters() const noexcept { return max_iters_; }
  /**
  * Gets the relative residual goal of the solver.
  *
  * @return The relative residual goal.
  */
  - remove_complex<value_type> get_rel_residual_goal() const
  + remove_complex<value_type> get_rel_residual_goal() const noexcept
  {
  return rel_residual_goal_;
  }
  