pop_front

pop_front_t kumi::pop_front {}

inlineconstexprnodiscard

Callable object removing the first (if any) element of t.

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

Header file

#include <kumi/algorithm/push_pop.hpp>

Call Signature

template<product_type T>
constexpr auto pop_front(T && t);

Parameters

• t: Base product type

Return value

• A product type composed of all elements of t except its first. Has no effect on empty product types.

Helper type

    template<kumi::concepts::product_type T> using pop_front_t = decltype(kumi::pop_front(std::declval<T>()));
 
    template<kumi::concepts::product_type T> struct pop_front
    {
      using type = kumi::result::pop_front_t<T>;
    };
 

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

Examples

• Tuple

  
  #include <kumi/kumi.hpp>
  #include <iostream>
   
  int main()
  {
    std::cout << kumi::pop_front( kumi::tuple{} )  << "\n";
   
    kumi::tuple t{1,2.,3.4f};
    std::cout << t                    << "\n";
    std::cout << kumi::pop_front(t)   << "\n";
  }

• Record

  
  #include <kumi/kumi.hpp>
  #include <iostream>
   
  int main()
  {
    using namespace kumi::literals;
    std::cout << kumi::pop_front( kumi::record{} )  << "\n";
   
    kumi::record r{"a"_id = 1,"b"_id = 2.,"c"_id = 3.4f};
    std::cout << r                    << "\n";
    std::cout << kumi::pop_front(r)   << "\n";
  }