/*******************************************************************************
 *
 * TRIQS: a Toolbox for Research in Interacting Quantum Systems
 *
 * Copyright (C) 2011 by O. Parcollet
 *
 * TRIQS is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * TRIQS. If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#ifndef TRIQS_MEMCOPY_H
#define TRIQS_MEMCOPY_H
#include "../../utility/exceptions.hpp"

namespace triqs { namespace arrays { namespace storages {

 // beware : complex is not a pod
 template <class S> struct is_scalar_or_pod : std::integral_constant<bool, std::is_arithmetic<S>::value || triqs::is_complex<S>::value || std::is_pod<S>::value > {};

 // copy such that it is a fast memcpy for scalar / pod objects
 // when not a scalar object, loop on elements

 template<typename T1, typename T2>
  void memcopy_impl (T1 * restrict p1, const T2 * restrict p2, size_t size, std::false_type) { for (size_t i = 0; i < size; ++i) p1[i] = p2[i]; }

 template<typename T>
  void memcopy_impl (T * restrict p1, const T * restrict p2, size_t size, std::true_type) {
   if (std::abs(p2-p1)>size) {memcpy (p1, p2, size * sizeof(T));} // guard against aliasing of data
   else { memcopy_impl(p1,p2,size,std::false_type());}
  }

 template<typename T1, typename T2>
  void memcopy (T1 * restrict p1, const T2 * restrict p2, size_t size) {
   constexpr bool use_memcpy =  std::is_pod<T1>::value &&
    std::is_same< typename std::remove_cv<T1>::type, typename std::remove_cv<T2>::type>::value;
   memcopy_impl(p1,p2,size,std::integral_constant<bool, use_memcpy>());
  }

}}}
#endif