push_front

push_front_t kumi::push_front {}

inlineconstexprnodiscard

Callable object constructing a product type by adding a value v at the beginning 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, typename V>
constexpr auto push_front(T && t, V && v);

Parameters

• t: Base product type
• v: Value to insert in front of t

Return value

• A product type composed of v followed by all elements of t in order.

Helper type

    template<kumi::concepts::product_type T, typename V>
    using push_front_t = decltype(kumi::push_front(std::declval<T>(), std::declval<V>()));
 
    template<kumi::concepts::product_type T, typename V> struct push_front
    {
      using type = kumi::result::push_front_t<T, V>;
    };
 

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

Examples

• Tuple

  
  #include <kumi/kumi.hpp>
  #include <iostream>
   
  int main()
  {
    std::cout << kumi::push_front( kumi::tuple{}, 63.21)  << "\n";
   
    kumi::tuple t{1,2.,3.4f};
    std::cout << t                          << "\n";
    std::cout << kumi::push_front(t, 'Z')   << "\n";
  }

• Record

  
  #include <kumi/kumi.hpp>
  #include <iostream>
   
  int main()
  {
    using namespace kumi::literals;
   
    std::cout << kumi::push_front( kumi::record{}, "a"_id = 63.21)  << "\n";
   
    kumi::record t{"a"_id = 1,"b"_id = 2.,"c"_id = 3.4f};
    std::cout << t                          << "\n";
    std::cout << kumi::push_front(t, "d"_id = 'Z')   << "\n";
  }