windows()

template<std::size_t N, concepts::product_type T>

auto kumi::windows ( T && t )

inlinenodiscardconstexpr

Creates a tuple of product types, each containing N consecutive elements from t. Windows starts at 0 and advance by 1 element each time.

On record types, this function operates on elements as if they were ordered. The considered order is the order of declaration.

Template Parameters

N	Size of the window to generate

Parameters

t	the product type from which to extract the windows

Returns

A tuple of product types, each containing N consecutive elements of t

Note

Windows behaves like overlapping tiles: each inner product_type is a tile over t starting at index tile_number. All the windows are of the same size.

Helper type

namespace kumi::result
{
  template<std::size_t N, product_type T> struct windows;
 
  template<std::size_t N, product_type T>
  using windows_t = typename windows<N, T>::type;
}

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

Examples:

Tuple:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  auto t = kumi::tuple{1, 'y', 3.f, short{55}, -8, 66., "Pete"};
 
  auto w = kumi::windows<3>(t); 
  std::cout << "  Standard Windows " << "\n";
  std::cout << w << "\n";
 
  kumi::for_each([&](auto tile)
  {
    get<0>(tile)++;
  },w);
  std::cout << t << "\n";
 
  auto w2 = kumi::windows<3>(kumi::to_ref(t)); 
  std::cout << "  Windows with references " << "\n";
  std::cout << w2 << "\n";
 
  kumi::for_each([&](auto tile)
  {
    get<0>(tile)++;
  },w2);
  std::cout << t << "\n";   
}

Record:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
 
  auto r = kumi::record{"a"_id = 1, "b"_id = 'y', "c"_id = 3.f, "d"_id = short{55}
                       ,"e"_id = -8, "f"_id = 66., "g"_id = "Pete"};
 
  auto w = kumi::windows<3>(r); 
  std::cout << "  Standard Windows " << "\n";
  std::cout << w << "\n";
 
  kumi::for_each([&](auto tile)
  {
    get<0>(kumi::values_of(tile))++;
  },w);
  std::cout << r << "\n";
 
  auto w2 = kumi::windows<3>(kumi::to_ref(r)); 
  std::cout << "  Windows with references " << "\n";
  std::cout << w2 << "\n";
 
  kumi::for_each([&](auto tile)
  {
    get<0>(kumi::values_of(tile))++;
  },w2);
  std::cout << r << "\n";   
}