//********************************************************
// The following code example is taken from the book
//  C++20 - The Complete Guide
//  by Nicolai M. Josuttis (www.josuttis.com)
//  http://www.cppstd20.com
//
// The code is licensed under a
//  Creative Commons Attribution 4.0 International License
//  http://creativecommons.org/licenses/by/4.0/
//********************************************************


#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;
}