kumi::common_product_type< Ts > Struct Template Reference

Extracts the common product_type of a parameter pack. More...

#include <kumi/utils/builder.hpp>

Detailed Description

template<typename... Ts>
struct kumi::common_product_type< Ts >

Extracts the common product_type of a parameter pack.

If all the types are record types then it returns an empty record type, otherwise returns an empty product type. As we are unable to compute the Least Restrictive Subtype of a pack, this trait should be specialized for each case one would want to write. In the library, it is specialized for kumi::concepts::product_type and kumi::concepts::record_type. It is used in algorithm taking multiple product types as input in order to determine the correct output type.

Template Parameters

Ts	The product types to access

Helper type

namespace kumi
{
  template<typename... Ts> using common_product_type_t = typename common_product_type<Ts...>::type;
}

Example

struct cplx{ float re, im; };
 
template<typename... Ts> requires (std::is_same_v<Ts, cplx>)
struct kumi::common_product_type<Ts...>
{
  using type = cplx;
};