pop_back

pop_back_t kumi::pop_back {}

inlineconstexprnodiscard

Callable object removing the last (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_back(T && t);

Parameters

• t: Base product type

Return value

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

Helper type

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

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

Examples

• Tuple

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

• Record

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