min_element

eve::algo::min_element = function_with_traits<min_element_>

inlineconstexpr

#include <eve/module/algo/algo/min_element.hpp>

Note

for equivalent elements we return the first amoung equal.

we assume that eve::is_less defined for your type is total order. (this comes up when switching min with max)

Alternative Header

#include <eve/algo.hpp>

Callable Signatures

namespace eve::algo
{
   template<relaxed_range Rng, typename Less>
   auto min_element(Rng&& rng, Less less) -> unaligned_iterator_t<Rng>;   // 1
 
   template<relaxed_range Rng>
   auto min_element(Rng&& rng) -> unaligned_iterator_t<Rng>;            // 2
}

1. Returns the position of a minimum value, according to less. If the range is empty - returns past the end.
2. Same as 1 but the less is eve::is_less

Parameters

• rng: Relaxed input range to process
• less: SIMD strict weak ordering.

Return value

iterator to min element (end if the range is empty).

Example

#include <eve/module/core.hpp>
#include <eve/module/algo.hpp>
#include <tts/tts.hpp>  // as_string
#include <vector>
 
int main()
{
  std::vector<int> v{ 2, -1, 4, -1, 0 };
 
  std::cout << " -> v                                                                              = "
            << tts::as_string(v)
            << "\n";
 
  std::cout << " -> eve::algo::min_value(v)                                                       = "
            << *eve::algo::min_value(v) << "\n";
 
  std::cout << " -> eve::algo::min_element(v) - v.begin()                                         = "
            << eve::algo::min_element(v) - v.begin() << "\n";
 
  std::cout << " -> eve::algo::min_value(v, eve::is_greater)                                      = "
            << *eve::algo::min_value(v, eve::is_greater) << "\n";
 
  std::cout << " -> eve::algo::min_value(v, eve::is_greater) - v.begin()                          = "
            << eve::algo::min_element(v, eve::is_greater) - v.begin() << "\n";
 
 
  auto absolutes = eve::views::map(v, eve::abs);
  std::cout << " -> eve::algo::min_element[eve::algo::single_pass](absolutes) - absolutes.begin() = "
            << eve::algo::min_element[eve::algo::single_pass](absolutes) - absolutes.begin() << "\n";
 
}

See also

min_value

max_element

Note

if you just need a value and not position, use eve::algo::min_value.

Can be one of two algorithms: one pass and two pass (default).

Two pass finds a value and then does a linear search for the value. This proves to be faster on smaller simpler arrays. By default unrolls by 4 and aligned all memory accesses.

The one pass version keeps track of index and is better suited for complicated predicates. You can opt in by using single_pass or expensive_callable traits. The single_pass opt-in will be aligning all data accesses