small_vector.h

/*
 *  Copyright (C) 2004-2021 Edward F. Valeev
 *
 *  This file is part of Libint.
 *
 *  Libint is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Libint 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with Libint.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#ifndef _libint2_include_libint2_util_smallvector_h_
#define _libint2_include_libint2_util_smallvector_h_
 
// Boost.Container's small_vector is interoperable with std::vector starting with version 1.61 or later
// see https://www.boost.org/doc/libs/1_61_0/doc/html/boost/container/small_vector.html#idp20337968-bb
#if defined(__has_include)
#  if __has_include(<boost/version.hpp>) && __has_include(<boost/container/small_vector.hpp>) && !defined(LIBINT2_DISABLE_BOOST_CONTAINER_SMALL_VECTOR)
#    include <boost/version.hpp>  // read in version and do version check
#    if defined(BOOST_VERSION)
#      if (BOOST_VERSION / 100000 == 1) && ((BOOST_VERSION / 100 % 1000) >= 61)
#        define LIBINT2_HAS_BOOST_CONTAINER_SMALL_VECTOR_H 1
#        if !defined(LIBINT2_SVECTOR_OPTIMIZED_RANK)  // user can override by defining LIBINT2_SVECTOR_OPTIMIZED_RANK
#          define LIBINT2_SVECTOR_OPTIMIZED_RANK 6
#        endif
#        include <boost/container/small_vector.hpp>
#      endif  // boost version >= 1.61
#    endif  // defined(BOOST_VERSION)
#  else
#    include <vector>
#  endif
#else // defined(__has_include)
#  include <vector>
#endif // defined(__has_include)
 
namespace libint2 {
 
#if defined(LIBINT2_HAS_BOOST_CONTAINER_SMALL_VECTOR_H)
#define LIBINT2_USES_BOOST_CONTAINER_SMALL_VECTOR_AS_SVECTOR 1
template <typename T> using svector = boost::container::small_vector<T, LIBINT2_SVECTOR_OPTIMIZED_RANK>;
#else
template <typename T> using svector = std::vector<T>;
#endif
 
} // namespace libint2
 
#endif // header guard