// 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 fn_eps
//! @{

template <typename T1>
arma_warn_unused inline const eOp<T1, eop_eps> eps(
    const Base<typename T1::elem_type, T1>& X,
    const typename arma_not_cx<typename T1::elem_type>::result* junk = nullptr) {
  arma_debug_sigprint();
  arma_ignore(junk);

  return eOp<T1, eop_eps>(X.get_ref());
}

template <typename T1>
arma_warn_unused inline Mat<typename T1::pod_type> eps(
    const Base<std::complex<typename T1::pod_type>, T1>& X,
    const typename arma_cx_only<typename T1::elem_type>::result* junk = nullptr) {
  arma_debug_sigprint();
  arma_ignore(junk);

  typedef typename T1::pod_type T;
  typedef typename T1::elem_type eT;

  const unwrap<T1> tmp(X.get_ref());
  const Mat<eT>& A = tmp.M;

  Mat<T> out(A.n_rows, A.n_cols, arma_nozeros_indicator());

  T* out_mem = out.memptr();
  const eT* A_mem = A.memptr();

  const uword n_elem = A.n_elem;

  for (uword i = 0; i < n_elem; ++i) {
    out_mem[i] = eop_aux::direct_eps(A_mem[i]);
  }

  return out;
}

template <typename eT>
arma_warn_unused arma_inline typename arma_integral_only<eT>::result eps(const eT& x) {
  arma_ignore(x);

  return eT(0);
}

template <typename eT>
arma_warn_unused arma_inline typename arma_real_only<eT>::result eps(const eT& x) {
  return eop_aux::direct_eps(x);
}

template <typename T>
arma_warn_unused arma_inline typename arma_real_only<T>::result eps(
    const std::complex<T>& x) {
  return eop_aux::direct_eps(x);
}

//! @}
