transpose()

template<concepts::product_type 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 product type containing the transposed elements of t.

Note

This function will issue a compile time error if the each element of the input product type are not themselves product types or if their size are not equal.

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:

Tuple:

#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";
}

Record:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
 
  auto values = kumi::record{ "first"_id  = kumi::record{"a"_id=1, "b"_id='a', "c"_id=0.1   }
                            , "second"_id = kumi::record{"d"_id=2, "e"_id='b', "f"_id=0.01  }
                            };
 
  auto r = kumi::transpose( values );
  std::cout << r << "\n";
}