reorder_fields()

template<concepts::identifier auto... Name, concepts::product_type Tuple>

auto kumi::reorder_fields ( Tuple && t )

inlineconstexpr

Reorder elements of a kumi::record.

This function will issue a compile time error if the identifiers are not in t

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

Note

Nothing prevent the number of reordered names to be lesser or greater than t size or the fact they can appear multiple times if it is applied on a named tuple.

Template Parameters

Name	Reordered names of elements

Parameters

t	Product type to reorder

Returns

A product type with the type of t with elements equal to get<Name>(t).

Helper type

namespace kumi::result
{
  template<product_type Tuple,std::size_t... Idx> struct reorder_fields;
 
  template<product_type Tuple,std::size_t... Idx>
  using reorder_fields_t = typename reorder_fields<Tuple,Idx...>::type;
}

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

Example:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
 
  auto values = kumi::record { "a"_id = 1, "b"_id = 'a', "c"_id = 0.1 };
 
  std::cout << values << "\n";
  std::cout << kumi::reorder_fields<"b"_id,"a"_id,"c"_id>(values) << "\n";
}