max_value

eve::algo::max_value = function_with_traits<max_value_>[default_simple_algo_traits]

inlineconstexpr

#include <eve/algo/max_value.hpp>

SIMD algorithm that returns maximum value in the range.

The standard only has _element versions of min/max algorithms. However, in SIMD finding the value is much faster then also finding the position - hense this algorithm.

Note

for equivalent elements we return the second amoung equal.

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

Alternative Header

#include <eve/algo.hpp>

Callable Signatures

namespace eve::algo
{
  template <eve::algo::relaxed_range Rng, typename Less>
  std::optional<eve::value_type_t<Rng>> max_value(Rng&& rng, Less less);          // 1
 
  template <eve::algo::relaxed_range Rng>
  std::optional<eve::value_type_t<Rng>> max_value(Rng&& rng);                    // 2
}

1. Returns the maximum value, according to less. If the range is empty - returns nullopt.
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

maximum value from the range. If the input range was empty, it's std::nullopt.

Example

#include <eve/module/core.hpp>
#include <eve/algo.hpp>
#include <tts/tts.hpp>  // as_string
#include <vector>
 
int main()
{
  std::vector<int> v{ 2, 4, -1, 4, 0, 1 };
 
  std::cout << " -> v                                                       = "
            << tts::as_string(v)
            << "\n";
 
  std::cout << " -> eve::algo::max_value(v)                                 = "
            << *eve::algo::max_value(v) << "\n";
 
  std::cout << " -> eve::algo::max_element(v) - v.begin()                   = "
            << eve::algo::max_element(v) - v.begin() << "\n";
 
  std::cout << " -> eve::algo::max_value(v, eve::is_greater)                = "
            << *eve::algo::max_value(v, eve::is_greater) << "\n";
 
  std::cout << " -> eve::algo::max_value(v, eve::is_greater) - v.begin()    = "
            << eve::algo::max_element(v, eve::is_greater) - v.begin() << "\n";
}

See also

min_value

max_element