//********************************************************
// The following code example is taken from the book
//  C++23 - The Complete Guide
//  by Nicolai M. Josuttis (www.josuttis.com)
//  https://www.cppstd23.com
//
// The code is licensed under a
//  Creative Commons Attribution 4.0 International License
//  https://creativecommons.org/licenses/by/4.0/
//********************************************************


#include <print>
#include <spanstream>

int main()
{
  // fix-sized buffer initialized with 10 '?' and 5 null terminators:
  constexpr int len = 15;
  char buf[len]{};                            // braces to initialize with null terminators
  for (int i = 0; i < 10; ++i) buf[i] = '?';  // overwrite with 10 '?'
  std::println("buf: {:?} (size: {})", buf, std::size(buf));

  // create a span stream to the static char buffer:
  // - pass len-1 to keep last null terminator alive
  std::ospanstream ospStrm{{buf, len-1}};

  // skip 2 characters:
  ospStrm.seekp(2, std::ios::cur);

  // write doubles as long as the span stream is valid:
  for (int i = 0; ospStrm; ++i) {
    // print current content of buf and the span stream:
    std::println("buf: {}", buf);
    std::println("     {}", ospStrm.span());

    // write the next value:
    ospStrm << ' ' << i * 1.1;
  }
}