class layout_right
{
+public:
+ /*! \libinternal \brief Mapping from multidimensional indices within extents to 1D index.
+ * \tparam Extents the extents of the multidimensional integers for the mapping.
+ */
+ template<class Extents>
+ class mapping
+ {
+ private:
+ //! The extents.
+ Extents m_extents;
+
public:
- /*! \libinternal \brief Mapping from multidimensional indices within extents to 1D index.
- * \tparam Extents the extents of the multidimensional integers for the mapping.
+ //! exposing the type of indices
+ using index_type = ptrdiff_t;
+ //! exposing the type of the extents
+ using extents_type = Extents;
+ //! Default constructor.
+ constexpr mapping() noexcept = default;
+ //! Default move constructor.
+ constexpr mapping(mapping&&) noexcept = default;
+ //! Default copy constructor.
+ constexpr mapping(const mapping&) noexcept = default;
+ //! Default move assignment
+ mapping& operator=(mapping&&) noexcept = default;
+ //! Default copy assignment
+ mapping& operator=(const mapping&) noexcept = default;
+ /*! \brief Construct mapping, setting extents
+ * \param[in] ext the extents
*/
- template<class Extents>
- class mapping
- {
- private:
- //! The extents.
- Extents m_extents;
-
- public:
- //! exposing the type of indices
- using index_type = ptrdiff_t;
- //! exposing the type of the extents
- using extents_type = Extents;
- //! Default constructor.
- constexpr mapping() noexcept = default;
- //! Default move constructor.
- constexpr mapping( mapping && ) noexcept = default;
- //! Default copy constructor.
- constexpr mapping( const mapping & ) noexcept = default;
- //! Default move assignment
- mapping &operator= ( mapping && ) noexcept = default;
- //! Default copy assignment
- mapping &operator= ( const mapping & ) noexcept = default;
- /*! \brief Construct mapping, setting extents
- * \param[in] ext the extents
- */
- constexpr mapping( const Extents &ext ) noexcept
- : m_extents( ext ) {}
- /*! \brief Return the extents.
- * \returns extents
- */
- constexpr const Extents &extents() const noexcept { return m_extents; }
+ constexpr mapping(const Extents& ext) noexcept : m_extents(ext) {}
+ /*! \brief Return the extents.
+ * \returns extents
+ */
+ constexpr const Extents& extents() const noexcept { return m_extents; }
- private:
- /* \brief End recursion helper function for static offset calculation.
- * \param[in] sum The accumulated offset over all dimensions
- * \returns The offset.
- */
- static constexpr index_type
- offset( const size_t /*r*/, const ptrdiff_t sum)
- { return sum; }
+ private:
+ /* \brief End recursion helper function for static offset calculation.
+ * \param[in] sum The accumulated offset over all dimensions
+ * \returns The offset.
+ */
+ static constexpr index_type offset(const size_t /*r*/, const ptrdiff_t sum) { return sum; }
- /* \brief Statically calculate offset from index and extent.
- * For a multidimensional index (i0,i1,..,in), in a right memory
- * layout, 'i0' denotes the slowest moving dimension and
- * 'in' the fastest moving dimension.
- * The overall offset within extents N = (N0,..,Nn) is then
- * offest = i0 * N1 * .. * Nn + i1 * N2 * .. * Nn + in-1 * Nn + in
- * = (((i0*N1+i1)*N2+i2)*N3+i3) ...
- * \param[in] r current rank
- * \param[in] sum current sum up to this rank
- * \param[in] i index
- * \oaram[in] indices The rest of the paramter pack.
- * \returns The offset.
- */
- template<class ... Indices >
- inline constexpr index_type
- offset( const size_t r, ptrdiff_t sum, const index_type i, Indices... indices) const noexcept
- {
- return offset( r+1, sum * m_extents.extent(r) + i, indices ...);
- }
+ /* \brief Statically calculate offset from index and extent.
+ * For a multidimensional index (i0,i1,..,in), in a right memory
+ * layout, 'i0' denotes the slowest moving dimension and
+ * 'in' the fastest moving dimension.
+ * The overall offset within extents N = (N0,..,Nn) is then
+ * offest = i0 * N1 * .. * Nn + i1 * N2 * .. * Nn + in-1 * Nn + in
+ * = (((i0*N1+i1)*N2+i2)*N3+i3) ...
+ * \param[in] r current rank
+ * \param[in] sum current sum up to this rank
+ * \param[in] i index
+ * \oaram[in] indices The rest of the paramter pack.
+ * \returns The offset.
+ */
+ template<class... Indices>
+ inline constexpr index_type
+ offset(const size_t r, ptrdiff_t sum, const index_type i, Indices... indices) const noexcept
+ {
+ return offset(r + 1, sum * m_extents.extent(r) + i, indices...);
+ }
- public:
- /*! \brief Return the size of the underlying one-dimensional
- * data structure, so that the mapping is always valid.
- *
- * \returns number of span elements
- */
- constexpr index_type required_span_size() const noexcept
- {
- index_type size = 1;
- for (size_t r = 0; r < m_extents.rank(); r++)
- {
- size *= m_extents.extent(r);
- }
- return size;
- }
+ public:
+ /*! \brief Return the size of the underlying one-dimensional
+ * data structure, so that the mapping is always valid.
+ *
+ * \returns number of span elements
+ */
+ constexpr index_type required_span_size() const noexcept
+ {
+ index_type size = 1;
+ for (size_t r = 0; r < m_extents.rank(); r++)
+ {
+ size *= m_extents.extent(r);
+ }
+ return size;
+ }
- /*! \brief Map the multidimensional indices to 1D.
- * Requires number of indicies have the same dimensionality as the mapping.
- * \tparam Indices type of the indices to be mapped
- * \param[in] indices the indices to be mapped
- * \returns One-dimensional integer index.
- */
- template<class ... Indices >
- std::enable_if_t<sizeof ... (Indices) == Extents::rank(), index_type>
- constexpr operator()( Indices ... indices ) const noexcept
- { return offset( 0, 0, indices ... ); }
+ /*! \brief Map the multidimensional indices to 1D.
+ * Requires number of indicies have the same dimensionality as the mapping.
+ * \tparam Indices type of the indices to be mapped
+ * \param[in] indices the indices to be mapped
+ * \returns One-dimensional integer index.
+ */
+ template<class... Indices>
+ std::enable_if_t<sizeof...(Indices) == Extents::rank(), index_type> constexpr
+ operator()(Indices... indices) const noexcept
+ {
+ return offset(0, 0, indices...);
+ }
- //! Report that this mapping is always unique.
- static constexpr bool is_always_unique() noexcept { return true; }
- //! Report that this mapping is always contiguous.
- static constexpr bool is_always_contiguous() noexcept { return true; }
- //! Report that this mapping is always strided.
- static constexpr bool is_always_strided() noexcept { return true; }
+ //! Report that this mapping is always unique.
+ static constexpr bool is_always_unique() noexcept { return true; }
+ //! Report that this mapping is always contiguous.
+ static constexpr bool is_always_contiguous() noexcept { return true; }
+ //! Report that this mapping is always strided.
+ static constexpr bool is_always_strided() noexcept { return true; }
- //! Report that this mapping is unique.
- constexpr bool is_unique() const noexcept { return true; }
- //! Report that this mapping is contiguous.
- constexpr bool is_contiguous() const noexcept { return true; }
- //! Report that this mapping is strided.
- constexpr bool is_strided() const noexcept { return true; }
- /*!\brief Return the stride of dimension r.
- * \param[in] R rank of the stride to be queried.
- * \returns the stride along dimension r.
- */
- constexpr index_type stride(const size_t R) const noexcept
- {
- ptrdiff_t stride = 1;
- for (size_t r = m_extents.rank()-1; r > R; r--)
- {
- stride *= m_extents.extent(r);
- }
- return stride;
- }
+ //! Report that this mapping is unique.
+ constexpr bool is_unique() const noexcept { return true; }
+ //! Report that this mapping is contiguous.
+ constexpr bool is_contiguous() const noexcept { return true; }
+ //! Report that this mapping is strided.
+ constexpr bool is_strided() const noexcept { return true; }
+ /*!\brief Return the stride of dimension r.
+ * \param[in] R rank of the stride to be queried.
+ * \returns the stride along dimension r.
+ */
+ constexpr index_type stride(const size_t R) const noexcept
+ {
+ ptrdiff_t stride = 1;
+ for (size_t r = m_extents.rank() - 1; r > R; r--)
+ {
+ stride *= m_extents.extent(r);
+ }
+ return stride;
+ }
- }; // class mapping
+ }; // class mapping
-}; // class layout_right
+}; // class layout_right
-} // namespace gmx
-#endif /* end of include guard: MDSPAN_LAYOUTS_H */
+} // namespace gmx
+#endif /* end of include guard: MDSPAN_LAYOUTS_H */
biod.pnpi.spb.ru / alexxy / gromacs.git / blobdiff