message: Extended stopping_status with == and != operators
  Also made sure all variables are snake_case
diff: @@ -47,6 +47,28 @@ namespace gko {
  */
  class stopping_status {
  public:
  + /**
  + * Check if two stopping_status are identical
  + * @param other stopping_status to compare against
  + * @return true if and only if `*this == other`
  + */
  + GKO_ATTRIBUTES GKO_INLINE bool operator==(
  + const stopping_status &other) const noexcept
  + {
  + return data_ == other.data_;
  + }
  +
  + /**
  + * Check if two stopping_status are different
  + * @param other stopping_status to compare against
  + * @return true if and only if `*this != other`
  + */
  + GKO_ATTRIBUTES GKO_INLINE bool operator!=(
  + const stopping_status &other) const noexcept
  + {
  + return data_ != other.data_;
  + }
  +
  /**
  * Check if any stopping criteria was fulfilled.
  * @return Returns true if any stopping criteria was fulfilled.
  @@ -93,15 +115,15 @@ public:
  * Call if a stop occured due to a hard limit (and convergence was not
  * reached).
  * @param id id of the stopping criteria.
  - * @param setFinalized Controls if the current version should count as
  + * @param set_finalized Controls if the current version should count as
  * finalized (set to true) or not (set to false).
  */
  GKO_ATTRIBUTES GKO_INLINE void stop(uint8 id,
  - bool setFinalized = true) noexcept
  + bool set_finalized = true) noexcept
  {
  if (!this->has_stopped()) {
  data_ |= (id & id_mask_);
  - if (setFinalized) {
  + if (set_finalized) {
  data_ |= finalized_mask_;
  }
  }
  @@ -110,15 +132,15 @@ public:
  /**
  * Call if convergence occured.
  * @param id id of the stopping criteria.
  - * @param setFinalized Controls if the current version should count as
  + * @param set_finalized Controls if the current version should count as
  * finalized (set to true) or not (set to false).
  */
  GKO_ATTRIBUTES GKO_INLINE void converge(uint8 id,
  - bool setFinalized = true) noexcept
  + bool set_finalized = true) noexcept
  {
  if (!this->has_stopped()) {
  data_ |= converged_mask_ | (id & id_mask_);
  - if (setFinalized) {
  + if (set_finalized) {
  data_ |= finalized_mask_;
  }
  }
  