ranges/maxvalue2.hpp

The following code example is taken from the book
C++20 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2021
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <ranges>

template<std::ranges::input_range Range>
std::ranges::range_value_t<Range> maxValue(Range&& rg)
{
  if (std::ranges::empty(rg)) {
    return std::ranges::range_value_t<Range>{};
  }
  auto pos = std::ranges::begin(rg);
  auto max = *pos;
  while (++pos != std::ranges::end(rg)) {
    if (*pos > max) {
      max = *pos;
    }
  }
  return max;
}