in_dev.h

Go to the documentation of this file.

#ifndef __utl_dev_in_dev_h__
#define __utl_dev_in_dev_h__

#include <utl/core/impl.h>
#include <utl/core/crtp.h>
#include <utl/dev/dev_iterators.h>
#include <utl/meta/meta.h>

namespace utl {


   template <typename impl_t, typename data_t, size_t streamsize =0>
   class in_dev {
      _CRTP_IMPL(impl_t);
      using in_dev_t = in_dev <impl_t, data_t, streamsize>;    

      public:
         using data_type      = data_t;
         using pointer_type   = data_t*;
         using type = in_dev_t;      

   protected:
      ~in_dev () = default;                     
      in_dev () = default;                      
      in_dev(const in_dev_t&) = delete;               
      in_dev_t& operator= (const in_dev_t&) = delete; 

   private:
      size_t get_ (data_t& data) { return impl().get_ (data); }
      size_t get_ (data_t* data, size_t n) { return impl().get (data, n); }

   public:
      size_t get (data_t& data) {
         return get_ (data);
      }

      size_t get (data_t* data, size_t n) {
         return get_ (data, n);
      }

   public:
      template <typename _Dst_t>
      in_dev_t& operator>> (_Dst_t& dst) {
         static_assert ((sizeof (_Dst_t)%sizeof(data_t) == 0),
                        "Target size must be an integer multiple of device's data size");
         get_ (reinterpret_cast<data_t*>(&dst), sizeof(_Dst_t)/sizeof(data_t));
         return *this;
      }
      template <typename _Dst_t>
      in_dev_t& operator>> (_Dst_t* dst) = delete;

      in_dev_t& operator>> (data_t& dst) {
         get_ (dst);
         return *this;
      }

      using iterator       =  indev_it <in_dev_t, data_t*, streamsize>;         
      using const_iterator =  indev_it <in_dev_t, const data_t*, streamsize>;   

      iterator        begin ()       noexcept { return       iterator(this, iterator::init); }
      const_iterator  begin () const noexcept { return const_iterator(this, iterator::init); }
      const_iterator cbegin () const noexcept { return const_iterator(this, iterator::init); }
      iterator        end ()         noexcept { return       iterator(this, iterator::eos); }
      const_iterator  end ()   const noexcept { return const_iterator(this, iterator::eos); }
      const_iterator cend ()   const noexcept { return const_iterator(this, iterator::eos); }
   };

   template <typename data_t, size_t streamsize>
   class in_dev <virtual_tag, data_t, streamsize> {
      using in_dev_t = in_dev <virtual_tag, data_t, streamsize>;

   public:
      using data_type      = data_t;
      using pointer_type   = data_t*;
      using type = in_dev_t;    

   public:
      virtual ~in_dev () = default;             
   protected:
      in_dev () = default;                      
      in_dev(const in_dev_t&) = delete;               
      in_dev_t& operator= (const in_dev_t&) = delete; 

   private:
      virtual size_t get_ (data_t& data) = 0;

      virtual size_t get_ (data_t* data, size_t n) = 0;

   public:
      size_t get (data_t& data) { return get_ (data); }
      size_t get (data_t* data, size_t n) { return get_ (data, n); }

   public:
      template <typename _Dst_t>
      in_dev_t& operator>> (_Dst_t& dst) {
         static_assert ((sizeof (_Dst_t)%sizeof(data_t) == 0),
                        "Target size must be an integer multiple of device's data size");
         get_ (reinterpret_cast<data_t*>(&dst), sizeof(_Dst_t)/sizeof(data_t));
         return *this;
      }
      template <typename _Dst_t>
      in_dev_t& operator>> (_Dst_t* dst) = delete;

      in_dev_t& operator>> (data_t& dst) {
         get_ (dst);
         return *this;
      }

      using iterator       = indev_it <in_dev_t, data_t*, streamsize>;         
      using const_iterator = indev_it <in_dev_t, const data_t*, streamsize>;   

      iterator        begin ()       noexcept { return       iterator(this, iterator::init); }
      const_iterator  begin () const noexcept { return const_iterator(this, iterator::init); }
      const_iterator cbegin () const noexcept { return const_iterator(this, iterator::init); }
      iterator        end ()         noexcept { return       iterator(this, iterator::eos); }
      const_iterator  end ()   const noexcept { return const_iterator(this, iterator::eos); }
      const_iterator cend ()   const noexcept { return const_iterator(this, iterator::eos); }
   };

   /*
    * Input device predicate (concept)
    */
   namespace in_dev_details {
      using std::declval;

      // main api members
      template <class _Tp> using try_get1_t   = decltype (declval<_Tp>().get (declval<typename _Tp::data_type&>()));
      template <class _Tp> using try_get2_t   = decltype (declval<_Tp>().get (declval<typename _Tp::data_type*>(), declval<size_t>()));
      // operators
      //template <class _Tp> using try_extract_t= decltype (declval<_Tp>() >> declval<typename _Tp::data_type&>());
      // iterator members
      template <class _Tp> using try_begin_t  = decltype (declval<_Tp>().begin());
      template <class _Tp> using tryc_begin_t = decltype (declval<const _Tp>().begin());
      template <class _Tp> using try_cbegin_t = decltype (declval<const _Tp>().cbegin());
      template <class _Tp> using try_end_t    = decltype (declval<_Tp>().begin());
      template <class _Tp> using tryc_end_t   = decltype (declval<const _Tp>().begin());
      template <class _Tp> using try_cend_t   = decltype (declval<const _Tp>().cend());

      template <typename _Tp, typename =void>
      struct is_in_dev_ : false_ {};

      template <typename _Tp>
      struct is_in_dev_ <_Tp,
         void_t <
            typename _Tp::data_type,
            typename _Tp::pointer_type,
            typename _Tp::iterator,
            typename _Tp::const_iterator,
            use_if_same_t <try_get1_t <_Tp>,  size_t>,
            use_if_same_t <try_get2_t <_Tp>,  size_t>,
            //if_same_t <try_extract_t<_Tp>,typename _Tp&>,
            use_if_same_t <try_begin_t<_Tp>,  typename _Tp::iterator>,
            use_if_same_t <tryc_begin_t<_Tp>, typename _Tp::const_iterator>,
            use_if_same_t <try_cbegin_t<_Tp>, typename _Tp::const_iterator>,
            use_if_same_t <try_end_t<_Tp>,    typename _Tp::iterator>,
            use_if_same_t <tryc_end_t<_Tp>,   typename _Tp::const_iterator>,
            use_if_same_t <try_cend_t<_Tp>,   typename _Tp::const_iterator>
         >
      > : true_ {};
   }
   template <typename _Tp>
   constexpr bool In_dev = in_dev_details::is_in_dev_ <_Tp>::value;

}

#endif /* #ifndef __utl_dev_in_dev_h__ */