File flattenstd.h

File List > code_source > templat > include > TempLat > util > flattenstd.h
#ifndef TEMPLAT_UTIL_FLATTENSTD_H
#define TEMPLAT_UTIL_FLATTENSTD_H

/* This file is part of TempLat, available at https://cosmolattice.github.io/templat .
   Copyright 2021-2026 The TempLat authors, see AUTHORS.md.
   Released under the MIT license, see LICENSE.md. */

// File info: Main contributor(s): Adrien Florio, Year: 2025

#include "TempLat/util/stdatomictype.h"

#include <vector>

namespace TempLat
{
  template <typename T> struct is_std_vector : std::false_type {
  };

  template <typename T, typename A> struct is_std_vector<std::vector<T, A>> : std::true_type {
  };

  // Recursive flatten function for atomic types (leaf)
  template <typename T>
  typename std::enable_if<!is_std_vector<T>::value>::type flatten_helper(const T &elem, std::vector<T> &flat)
  {
    flat.push_back(elem);
  }

  // Recursive flatten function for vectors
  template <typename T>
  typename std::enable_if<is_std_vector<T>::value>::type
  flatten_helper(const T &nested, std::vector<typename std_atomic_type<T>::type> &flat)
  {
    for (const auto &elem : nested) {
      flatten_helper(elem, flat);
    }
  }

  template <typename NestedVec> std::vector<typename std_atomic_type<NestedVec>::type> flatten(const NestedVec &nested)
  {
    using AtomicT = typename std_atomic_type<NestedVec>::type;
    std::vector<AtomicT> flat;
    flatten_helper(nested, flat);
    return flat;
  }

} // namespace TempLat

#endif