#include <iostream>
#include <string>
#include <string_view>

void f(std::string_view sv)
{
  for (auto c : sv) std::cout << c;
}

auto trim(std::string_view sv, std::string_view delimiters = " \t\r\n")
{
  sv.remove_prefix(std::min(sv.find_first_not_of(delimiters), sv.size()));
  auto pos = sv.find_last_not_of(delimiters); 
  if (pos != sv.npos) sv.remove_suffix(sv.size() - (pos + 1));
  return sv;
}

int main()
{
  using namespace std::literals;
	
  const char arr[] = "Hello";
  auto s = "World!\n"s;
  auto sv = "This is a string_view: "sv;
	
  f(sv);
  f(arr);
  f({", ignored", 2});
  f(s);
  std::cout << trim("  This character sequence will be trimmed.   ") << "\n";
}