// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------

//! \addtogroup op_inv_spd
//! @{

class op_inv_spd_default : public traits_op_default {
 public:
  template <typename T1>
  inline static void apply(Mat<typename T1::elem_type>& out,
                           const Op<T1, op_inv_spd_default>& in);

  template <typename T1>
  inline static bool apply_direct(Mat<typename T1::elem_type>& out,
                                  const Base<typename T1::elem_type, T1>& expr);
};

class op_inv_spd_full : public traits_op_default {
 public:
  template <typename T1>
  inline static void apply(Mat<typename T1::elem_type>& out,
                           const Op<T1, op_inv_spd_full>& in);

  template <typename T1, const bool has_user_flags = true>
  inline static bool apply_direct(Mat<typename T1::elem_type>& out,
                                  const Base<typename T1::elem_type, T1>& expr,
                                  const uword flags);

  template <typename eT>
  arma_cold inline static bool apply_tiny_2x2(Mat<eT>& X);
};

template <typename T>
struct op_inv_spd_state {
  uword size = uword(0);
  T rcond = T(0);
  bool is_diag = false;
};

class op_inv_spd_rcond : public traits_op_default {
 public:
  template <typename T1>
  inline static bool apply_direct(Mat<typename T1::elem_type>& out_inv,
                                  op_inv_spd_state<typename T1::pod_type>& out_state,
                                  const Base<typename T1::elem_type, T1>& expr);
};

//! @}
