darray_ext_soa_impl.h

#pragma once
#include "gaia/config/config.h"
 
#include <cstddef>
#include <initializer_list>
#include <type_traits>
#include <utility>
 
#include "gaia/core/iterator.h"
#include "gaia/core/utility.h"
#include "gaia/mem/data_layout_policy.h"
#include "gaia/mem/mem_sani.h"
#include "gaia/mem/mem_utils.h"
#include "gaia/mem/raw_data_holder.h"
 
namespace gaia {
  namespace cnt {
    namespace darr_ext_soa_detail {
      using difference_type = uint32_t;
      using size_type = uint32_t;
    } // namespace darr_ext_soa_detail
 
    template <typename T>
    struct darr_ext_soa_iterator {
      using value_type = T;
      // using pointer = T*; not supported
      // using reference = T&; not supported
      using difference_type = darr_ext_soa_detail::difference_type;
      using size_type = darr_ext_soa_detail::size_type;
 
      using iterator = darr_ext_soa_iterator;
      using iterator_category = core::random_access_iterator_tag;
 
    private:
      uint8_t* m_ptr;
      uint32_t m_cnt;
      uint32_t m_idx;
 
    public:
      darr_ext_soa_iterator(uint8_t* ptr, uint32_t cnt, uint32_t idx): m_ptr(ptr), m_cnt(cnt), m_idx(idx) {}
 
      T operator*() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      T operator->() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      iterator operator[](size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
 
      iterator& operator+=(size_type diff) {
        m_idx += diff;
        return *this;
      }
      iterator& operator-=(size_type diff) {
        m_idx -= diff;
        return *this;
      }
      iterator& operator++() {
        ++m_idx;
        return *this;
      }
      iterator operator++(int) {
        iterator temp(*this);
        ++*this;
        return temp;
      }
      iterator& operator--() {
        --m_idx;
        return *this;
      }
      iterator operator--(int) {
        iterator temp(*this);
        --*this;
        return temp;
      }
 
      iterator operator+(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      iterator operator-(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      difference_type operator-(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return (difference_type)(m_idx - other.m_idx);
      }
 
      GAIA_NODISCARD bool operator==(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx == other.m_idx;
      }
      GAIA_NODISCARD bool operator!=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx != other.m_idx;
      }
      GAIA_NODISCARD bool operator>(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx > other.m_idx;
      }
      GAIA_NODISCARD bool operator>=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx >= other.m_idx;
      }
      GAIA_NODISCARD bool operator<(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx < other.m_idx;
      }
      GAIA_NODISCARD bool operator<=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx <= other.m_idx;
      }
    };
 
    template <typename T>
    struct const_darr_ext_soa_iterator {
      using value_type = T;
      // using pointer = T*; not supported
      // using reference = T&; not supported
      using difference_type = darr_ext_soa_detail::difference_type;
      using size_type = darr_ext_soa_detail::size_type;
 
      using iterator = const_darr_ext_soa_iterator;
      using iterator_category = core::random_access_iterator_tag;
 
    private:
      const uint8_t* m_ptr;
      uint32_t m_cnt;
      uint32_t m_idx;
 
    public:
      const_darr_ext_soa_iterator(const uint8_t* ptr, uint32_t cnt, uint32_t idx): m_ptr(ptr), m_cnt(cnt), m_idx(idx) {}
 
      T operator*() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      T operator->() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      iterator operator[](size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
 
      iterator& operator+=(size_type diff) {
        m_idx += diff;
        return *this;
      }
      iterator& operator-=(size_type diff) {
        m_idx -= diff;
        return *this;
      }
      iterator& operator++() {
        ++m_idx;
        return *this;
      }
      iterator operator++(int) {
        iterator temp(*this);
        ++*this;
        return temp;
      }
      iterator& operator--() {
        --m_idx;
        return *this;
      }
      iterator operator--(int) {
        iterator temp(*this);
        --*this;
        return temp;
      }
 
      iterator operator+(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      iterator operator-(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      difference_type operator-(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return (difference_type)(m_idx - other.m_idx);
      }
 
      GAIA_NODISCARD bool operator==(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx == other.m_idx;
      }
      GAIA_NODISCARD bool operator!=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx != other.m_idx;
      }
      GAIA_NODISCARD bool operator>(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx > other.m_idx;
      }
      GAIA_NODISCARD bool operator>=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx >= other.m_idx;
      }
      GAIA_NODISCARD bool operator<(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx < other.m_idx;
      }
      GAIA_NODISCARD bool operator<=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx <= other.m_idx;
      }
    };
 
    template <typename T, darr_ext_soa_detail::size_type N, typename Allocator = mem::DefaultAllocatorAdaptor>
    class darr_ext_soa {
      static_assert(mem::is_soa_layout_v<T>, "darr_ext_soa can be used only with soa types");
 
    public:
      static_assert(N > 0);
 
      using value_type = T;
      using reference = T&;
      using const_reference = const T&;
      using pointer = T*;
      using const_pointer = const T*;
      using view_policy = mem::data_view_policy_soa<T::gaia_Data_Layout, T>;
      using difference_type = darr_ext_soa_detail::difference_type;
      using size_type = darr_ext_soa_detail::size_type;
 
      using iterator = darr_ext_soa_iterator<T>;
      using const_iterator = const_darr_ext_soa_iterator<T>;
      using iterator_category = core::random_access_iterator_tag;
 
      static constexpr size_type extent = N;
      static constexpr uint32_t allocated_bytes = view_policy::get_min_byte_size(0, N);
 
    private:
      mem::raw_data_holder<T, allocated_bytes> m_data;
      uint8_t* m_pDataHeap = nullptr;
      uint8_t* m_pData = m_data;
      size_type m_cnt = size_type(0);
      size_type m_cap = extent;
 
      void try_grow() {
        const auto cnt = size();
        const auto cap = capacity();
 
        // Unless we reached the capacity don't do anything
        if GAIA_LIKELY (cnt < cap)
          return;
 
        // We increase the capacity in multiples of 1.5 which is about the golden ratio (1.618).
        // This means we prefer more frequent allocations over memory fragmentation.
        m_cap = (cap * 3 + 1) / 2;
 
        if GAIA_UNLIKELY (m_pDataHeap == nullptr) {
          // If no heap memory is allocated yet we need to allocate it and move the old stack elements to it
          m_pDataHeap = view_policy::template alloc<Allocator>(m_cap);
          view_policy::mem_add_block(m_pDataHeap, m_cap, cnt);
          mem::move_elements<T, true>(m_pDataHeap, m_data, cnt, 0, m_cap, cap);
        } else {
          // Move items from the old heap array to the new one. Delete the old
          auto* pDataOld = m_pDataHeap;
          m_pDataHeap = view_policy::template alloc<Allocator>(m_cap);
          view_policy::mem_add_block(m_pDataHeap, m_cap, cnt);
          mem::move_elements<T, true>(m_pDataHeap, pDataOld, cnt, 0, m_cap, cap);
          view_policy::template free<Allocator>(pDataOld, cap, cnt);
        }
 
        m_pData = m_pDataHeap;
      }
 
    public:
      darr_ext_soa() noexcept = default;
      darr_ext_soa(core::zero_t) noexcept {}
 
      darr_ext_soa(size_type count, const T& value) {
        resize(count);
        for (auto it: *this)
          *it = value;
      }
 
      darr_ext_soa(size_type count) {
        resize(count);
      }
 
      template <typename InputIt>
      darr_ext_soa(InputIt first, InputIt last) {
        const auto count = (size_type)core::distance(first, last);
        resize(count);
 
        if constexpr (std::is_pointer_v<InputIt>) {
          for (size_type i = 0; i < count; ++i)
            operator[](i) = first[i];
        } else if constexpr (std::is_same_v<typename InputIt::iterator_category, core::random_access_iterator_tag>) {
          for (size_type i = 0; i < count; ++i)
            operator[](i) = *(first[i]);
        } else {
          size_type i = 0;
          for (auto it = first; it != last; ++it)
            operator[](++i) = *it;
        }
      }
 
      darr_ext_soa(std::initializer_list<T> il): darr_ext_soa(il.begin(), il.end()) {}
 
      darr_ext_soa(const darr_ext_soa& other): darr_ext_soa(other.begin(), other.end()) {}
 
      darr_ext_soa(darr_ext_soa&& other) noexcept {
        GAIA_ASSERT(core::addressof(other) != this);
 
        // Moving from stack-allocated source
        if (other.m_pDataHeap == nullptr) {
          view_policy::mem_add_block(m_data, extent, other.size());
          mem::move_elements<T, true>(m_data, other.m_data, other.size(), 0, extent, other.extent);
          view_policy::mem_del_block(other.m_data, extent, other.size());
          m_pDataHeap = nullptr;
          m_pData = m_data;
        } else {
          m_pDataHeap = other.m_pDataHeap;
          m_pData = m_pDataHeap;
        }
 
        m_cnt = other.m_cnt;
        m_cap = other.m_cap;
 
        other.m_pDataHeap = nullptr;
        other.m_pData = other.m_data;
        other.m_cnt = size_type(0);
        other.m_cap = extent;
      }
 
      darr_ext_soa& operator=(std::initializer_list<T> il) {
        *this = darr_ext_soa(il.begin(), il.end());
        return *this;
      }
 
      darr_ext_soa& operator=(const darr_ext_soa& other) {
        GAIA_ASSERT(core::addressof(other) != this);
 
        resize(other.size());
        mem::copy_elements<T, true>(
            (uint8_t*)m_pData, (const uint8_t*)other.m_pData, other.size(), 0, capacity(), other.capacity());
 
        return *this;
      }
 
      darr_ext_soa& operator=(darr_ext_soa&& other) noexcept {
        GAIA_ASSERT(core::addressof(other) != this);
 
        // Release previously allocated memory if there was anything
        view_policy::template free<Allocator>(m_pDataHeap, m_cap, m_cnt);
 
        // Moving from stack-allocated source
        if (other.m_pDataHeap == nullptr) {
          view_policy::mem_add_block(m_data, extent, other.size());
          mem::move_elements<T, true>(m_data, other.m_data, other.size(), 0, extent, other.extent);
          view_policy::mem_del_block(other.m_data, extent, other.size());
          m_pDataHeap = nullptr;
          m_pData = m_data;
        } else {
          m_pDataHeap = other.m_pDataHeap;
          m_pData = m_pDataHeap;
        }
 
        m_cnt = other.m_cnt;
        m_cap = other.m_cap;
 
        other.m_cnt = size_type(0);
        other.m_cap = extent;
        other.m_pDataHeap = nullptr;
        other.m_pData = other.m_data;
 
        return *this;
      }
 
      ~darr_ext_soa() {
        view_policy::template free<Allocator>(m_pDataHeap, m_cap, m_cnt);
      }
 
      GAIA_CLANG_WARNING_PUSH()
      // Memory is aligned so we can silence this warning
      GAIA_CLANG_WARNING_DISABLE("-Wcast-align")
 
      GAIA_NODISCARD pointer data() noexcept {
        return reinterpret_cast<pointer>(m_pData);
      }
 
      GAIA_NODISCARD const_pointer data() const noexcept {
        return reinterpret_cast<const_pointer>(m_pData);
      }
 
      GAIA_NODISCARD decltype(auto) operator[](size_type pos) noexcept {
        GAIA_ASSERT(pos < size());
        return view_policy::set({(typename view_policy::TargetCastType)m_pData, size()}, pos);
      }
 
      GAIA_NODISCARD decltype(auto) operator[](size_type pos) const noexcept {
        GAIA_ASSERT(pos < size());
        return view_policy::get({(typename view_policy::TargetCastType)m_pData, size()}, pos);
      }
 
      GAIA_CLANG_WARNING_POP()
 
      void reserve(size_type cap) {
        if (cap <= m_cap)
          return;
 
        auto* pDataOld = m_pDataHeap;
        m_pDataHeap = view_policy::template alloc<Allocator>(cap);
        view_policy::mem_add_block(m_pDataHeap, cap, m_cnt);
        if (m_pDataHeap) {
          mem::move_elements<T, true>(m_pDataHeap, pDataOld, m_cnt, 0, cap, m_cap);
          view_policy::template free<Allocator>(pDataOld, m_cap, m_cnt);
        } else {
          m_pDataHeap = view_policy::template alloc<Allocator>(cap);
          mem::move_elements<T, true>(m_pDataHeap, m_data, m_cnt, 0, cap, m_cap);
        }
 
        m_cap = cap;
        m_pData = m_pDataHeap;
      }
 
      void resize(size_type count) {
        if (count == m_cnt)
          return;
 
        // Resizing to a smaller size
        if (count < m_cnt) {
          view_policy::mem_pop_block(data(), m_cap, m_cnt, m_cnt - count);
 
          m_cnt = count;
          return;
        }
 
        // Resizing to a bigger size but still within allocated capacity
        if (count <= m_cap) {
          view_policy::mem_push_block(data(), m_cap, m_cnt, count - m_cnt);
 
          m_cnt = count;
          return;
        }
 
        auto* pDataOld = m_pDataHeap;
        m_pDataHeap = view_policy::template alloc<Allocator>(count);
        view_policy::mem_add_block(m_pDataHeap, count, count);
        if (pDataOld != nullptr) {
          mem::move_elements<T, true>(m_pDataHeap, pDataOld, m_cnt, 0, count, m_cap);
          view_policy::template free<Allocator>(pDataOld, m_cap, m_cnt);
        } else {
          mem::move_elements<T, true>(m_pDataHeap, m_data, m_cnt, 0, count, m_cap);
          view_policy::mem_del_block(m_data, m_cap, m_cnt);
        }
 
        m_cap = count;
        m_cnt = count;
        m_pData = m_pDataHeap;
      }
 
      void push_back(const T& arg) {
        try_grow();
 
        view_policy::mem_push_block(data(), m_cap, m_cnt, 1);
        operator[](m_cnt++) = arg;
      }
 
      void push_back(T&& arg) {
        try_grow();
 
        view_policy::mem_push_block(data(), m_cap, m_cnt, 1);
        operator[](m_cnt++) = GAIA_MOV(arg);
      }
 
      template <typename... Args>
      decltype(auto) emplace_back(Args&&... args) {
        try_grow();
 
        view_policy::mem_push_block(data(), m_cap, m_cnt, 1);
        operator[](m_cnt++) = T(GAIA_FWD(args)...);
      }
 
      void pop_back() noexcept {
        GAIA_ASSERT(!empty());
 
        view_policy::mem_pop_block(data(), m_cap, m_cnt, 1);
 
        --m_cnt;
      }
 
      iterator insert(iterator pos, const T& arg) {
        GAIA_ASSERT(pos >= data());
        GAIA_ASSERT(empty() || (pos < iterator(data() + size())));
 
        const auto idxSrc = (size_type)core::distance(begin(), pos);
        try_grow();
        const auto idxDst = (size_type)core::distance(begin(), end()) + 1;
 
        view_policy::mem_push_block(data(), m_cap, m_cnt, 1);
        mem::shift_elements_right<T, true>(m_pData, idxDst, idxSrc, m_cap);
 
        operator[](idxSrc) = arg;
 
        ++m_cnt;
 
        return iterator(m_pData, capacity(), idxSrc);
      }
 
      iterator insert(iterator pos, T&& arg) {
        GAIA_ASSERT(pos >= data());
        GAIA_ASSERT(empty() || (pos < iterator(data() + size())));
 
        const auto idxSrc = (size_type)core::distance(begin(), pos);
        try_grow();
        const auto idxDst = (size_type)core::distance(begin(), end());
 
        view_policy::mem_push_block(data(), m_cap, m_cnt, 1);
        mem::shift_elements_right<T, true>(m_pData, idxDst, idxSrc, m_cap);
 
        operator[](idxSrc) = GAIA_MOV(arg);
 
        ++m_cnt;
 
        return iterator(m_pData, capacity(), idxSrc);
      }
 
      iterator erase(iterator pos) noexcept {
        GAIA_ASSERT(pos >= data());
        GAIA_ASSERT(empty() || (pos < iterator(data() + size())));
 
        if (empty())
          return end();
 
        const auto idxSrc = (size_type)core::distance(begin(), pos);
        const auto idxDst = (size_type)core::distance(begin(), end()) - 1;
 
        mem::shift_elements_left<T, true>(m_pData, idxDst, idxSrc, m_cap);
        view_policy::mem_pop_block(data(), m_cap, m_cnt, 1);
 
        --m_cnt;
 
        return iterator(m_pData, capacity(), idxSrc);
      }
 
      iterator erase(iterator first, iterator last) noexcept {
        GAIA_ASSERT(first >= data())
        GAIA_ASSERT(empty() || (first < iterator(data() + size())));
        GAIA_ASSERT(last > first);
        GAIA_ASSERT(last <= iterator(data() + size()));
 
        if (empty())
          return end();
 
        const auto idxSrc = (size_type)core::distance(begin(), first);
        const auto idxDst = size();
        const auto cnt = (size_type)(last - first);
 
        mem::shift_elements_left_fast<T, true>(m_pData, idxDst, idxSrc, cnt, m_cap);
        view_policy::mem_pop_block(data(), m_cap, m_cnt, cnt);
 
        m_cnt -= cnt;
 
        return iterator(m_pData, capacity(), idxSrc);
      }
 
      void clear() noexcept {
        resize(0);
      }
 
      void shrink_to_fit() {
        const auto cap = capacity();
        const auto cnt = size();
 
        if (cap == cnt)
          return;
 
        if (m_pDataHeap != nullptr) {
          auto* pDataOld = m_pDataHeap;
 
          if (cnt < extent) {
            mem::move_elements<T, true>(m_data, pDataOld, cnt, 0);
            m_pData = m_data;
            m_cap = extent;
          } else {
            m_pDataHeap = view_policy::template alloc<Allocator>(m_cap = cnt);
            view_policy::mem_add_block(m_pDataHeap, m_cap, m_cnt);
            mem::move_elements<T, true>(m_pDataHeap, pDataOld, cnt, 0);
            m_pData = m_pDataHeap;
          }
 
          view_policy::mem_del_block(pDataOld, cap, cnt);
          view_policy::template free<Allocator>(pDataOld);
        } else
          resize(cnt);
      }
 
      template <typename Func>
      auto retain(Func&& func) noexcept {
        size_type erased = 0;
        size_type idxDst = 0;
        size_type idxSrc = 0;
 
        while (idxSrc < m_cnt) {
          if (func(operator[](idxSrc))) {
            if (idxDst < idxSrc) {
              auto* ptr = (uint8_t*)data();
              mem::move_elements<T, true>(ptr, ptr, idxDst, idxSrc, m_cap, m_cap);
            }
            ++idxDst;
          } else {
            ++erased;
          }
 
          ++idxSrc;
        }
 
        view_policy::mem_pop_block(data(), m_cap, m_cnt, erased);
 
        m_cnt -= erased;
        return idxDst;
      }
 
      GAIA_NODISCARD size_type size() const noexcept {
        return m_cnt;
      }
 
      GAIA_NODISCARD bool empty() const noexcept {
        return size() == 0;
      }
 
      GAIA_NODISCARD size_type capacity() const noexcept {
        return m_cap;
      }
 
      GAIA_NODISCARD size_type max_size() const noexcept {
        return N;
      }
 
      GAIA_NODISCARD decltype(auto) front() noexcept {
        GAIA_ASSERT(!empty());
        return *begin();
      }
 
      GAIA_NODISCARD decltype(auto) front() const noexcept {
        GAIA_ASSERT(!empty());
        return *begin();
      }
 
      GAIA_NODISCARD decltype(auto) back() noexcept {
        GAIA_ASSERT(!empty());
        return operator[](m_cnt - 1);
      }
 
      GAIA_NODISCARD decltype(auto) back() const noexcept {
        GAIA_ASSERT(!empty());
        return operator[](m_cnt - 1);
      }
 
      GAIA_NODISCARD auto begin() noexcept {
        return iterator(m_pData, capacity(), 0);
      }
 
      GAIA_NODISCARD auto begin() const noexcept {
        return const_iterator(m_pData, capacity(), 0);
      }
 
      GAIA_NODISCARD auto cbegin() const noexcept {
        return const_iterator(m_pData, capacity(), 0);
      }
 
      GAIA_NODISCARD auto rbegin() noexcept {
        return iterator(m_pData, capacity(), size() - 1);
      }
 
      GAIA_NODISCARD auto rbegin() const noexcept {
        return const_iterator(m_pData, capacity(), size() - 1);
      }
 
      GAIA_NODISCARD auto crbegin() const noexcept {
        return const_iterator(m_pData, capacity(), size() - 1);
      }
 
      GAIA_NODISCARD auto end() noexcept {
        return iterator(m_pData, capacity(), size());
      }
 
      GAIA_NODISCARD auto end() const noexcept {
        return const_iterator(m_pData, capacity(), size());
      }
 
      GAIA_NODISCARD auto cend() const noexcept {
        return const_iterator(m_pData, capacity(), size());
      }
 
      GAIA_NODISCARD auto rend() noexcept {
        return iterator(m_pData, capacity(), -1);
      }
 
      GAIA_NODISCARD auto rend() const noexcept {
        return const_iterator(m_pData, capacity(), -1);
      }
 
      GAIA_NODISCARD auto crend() const noexcept {
        return const_iterator(m_pData, capacity(), -1);
      }
 
      GAIA_NODISCARD bool operator==(const darr_ext_soa& other) const noexcept {
        if (m_cnt != other.m_cnt)
          return false;
        const size_type n = size();
        for (size_type i = 0; i < n; ++i)
          if (!(operator[](i) == other[i]))
            return false;
        return true;
      }
 
      GAIA_NODISCARD constexpr bool operator!=(const darr_ext_soa& other) const noexcept {
        return !operator==(other);
      }
 
      template <size_t Item>
      auto view_mut() noexcept {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::template set<Item>(
            std::span<uint8_t>{GAIA_ACC((uint8_t*)m_pData), capacity()});
      }
 
      template <size_t Item>
      auto view() const noexcept {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::template get<Item>(
            std::span<const uint8_t>{GAIA_ACC((const uint8_t*)m_pData), capacity()});
      }
    };
 
    namespace detail {
      template <typename T, uint32_t N, uint32_t... I>
      darr_ext_soa<std::remove_cv_t<T>, N> to_sarray_impl(T (&a)[N], std::index_sequence<I...> /*no_name*/) {
        return {{a[I]...}};
      }
    } // namespace detail
 
    template <typename T, uint32_t N>
    darr_ext_soa<std::remove_cv_t<T>, N> to_sarray(T (&a)[N]) {
      return detail::to_sarray_impl(a, std::make_index_sequence<N>{});
    }
 
  } // namespace cnt
 
} // namespace gaia