transpose()

template<concepts::product_type T>
requires (_::supports_transpose<T>)

auto kumi::transpose ( T && t )

inlinenodiscardconstexpr

Transpose a product type of product types by shifting elements in their transposed position always returning a tuple as the external product type.

Parameters

t	Product type to transpose

Returns

A tuple containing the transposed elements of t.

Helper type

namespace kumi::result
{
  template<product_type T> struct transpose;
 
  template<product_type T>
  using transpose_t = typename transpose<T>::type;
}

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

Examples:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  auto values = kumi::tuple { kumi::tuple{ 1, 'a', 0.1   }
                            , kumi::tuple{ 2, 'b', 0.01  }
                            };
 
  auto r = kumi::transpose(values );
  std::cout << r << "\n";
}

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
 
  auto status = kumi::record{"a"_id = true, "b"_id = false};
  auto id     = kumi::record{"aa"_id = 'a', "bb"_id = 'b', "cc"_id = 'c'};
  auto value  = kumi::record{"aaa"_id = 1.0,"bbb"_id = 2.1, "ccc"_id = 4.2, "d"_id = 8.4};
 
  auto r = kumi::cartesian_product( status, id, value );
 
  kumi::for_each_index( [](auto i, auto e)
                        {
                          std::cout << "# "  << i
                                    << ":"  << std::boolalpha
                                    << e    << "\n";
                        }
                      , r
                      );
}