inclusive_scan_right

inclusive_scan_right_t kumi::inclusive_scan_right {}

inlineconstexprnodiscard

Callable object computing the inclusive suffix scan of all elements of a product type using a non-tail recursive call.

On record types, this function operates on the underlying values, not on the fields themselves.

Note

The first stored value is the result of the application of the function to the provided initial value and the first element of the product_type.

Header file

#include <kumi/algorithm/scan.hpp>

Call Signature

template<typename Function, product_type T, typename Value>
constexpr auto inclusive_scan_right(Function f, T && t, Value init);

template<monoid M, typename Function, product_type T, typename Value>
constexpr auto inclusive_scan_right(M && m, T && t);

Parameters

• m: Monoid callable function to apply
• f: Binary callable function to apply
• t: Product Type to operate on
• init: Optional initial value of the scan

Return value

• A tuple of suffix partial accumulations where each element 'I' equals f(get<0>(t), f(... , f(get<N-1>(t), init))

Helper type

    template<typename Function, kumi::concepts::product_type T, typename Value = void> struct inclusive_scan_right
    {
      using type =
        decltype(kumi::inclusive_scan_right(std::declval<Function>(), std::declval<T>(), std::declval<Value>()));
    };
 
    template<typename Function, kumi::concepts::product_type T> struct inclusive_scan_right<Function, T>
    {
      using type = decltype(kumi::inclusive_scan_right(std::declval<Function>(), std::declval<T>()));
    };
 
    template<typename Function, kumi::concepts::product_type T, typename Value = void>
    using inclusive_scan_right_t = typename kumi::result::inclusive_scan_right<Function, T, Value>::type;
 

Computes the return type of a call to kumi::inclusive_scan_right

Examples

Tuple

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  auto t = kumi::tuple{2.,1,short{55},'z'};
 
  auto output = kumi::inclusive_scan_right( [](auto elt, auto acc) 
                  { 
                    return acc + sizeof(elt); 
                  }
                  , t
                  , std::size_t{42}                
                );
 
  std::cout << output << "\n"; 
 
  auto u = kumi::tuple{1,3,2,4,0,5,9,6,7};
 
  std::cout << kumi::inclusive_scan_right(kumi::function::plus, u) << "\n";
}

Record

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
  auto r = kumi::record{"a"_id = 2.,"b"_id = 1,"c"_id = short{55},"d"_id = 'z'};
 
  auto output = kumi::inclusive_scan_right( [](auto elt, auto acc) 
                  { 
                    return acc + sizeof(elt); 
                  }
                  , r
                  , std::size_t{42}                
                );
 
  std::cout << output << "\n"; 
 
  auto u = kumi::record{"a"_id = 1,"b"_id = 3,"c"_id = 2,"d"_id = 4, "e"_id = 0
                      , "f"_id = 5,"g"_id = 9,"h"_id = 6,"i"_id = 7};
 
  std::cout << kumi::inclusive_scan_right(kumi::function::plus, u) << "\n";
}