// ISO/IEC 14882:2020 (C++20) - standard headers
/*
<iostream> <algorithm> <variant> <numbers>
<any> <fstream> <numeric> <streambuf>
<array> <functional> <optional> <string>
<atomic> <future> <ostream> <string_view>
<barrier> <vector> <queue> <strstream>
<bit> <iomanip> <random> <syncstream>
<bitset> <ios> <ranges> <system_error>
<charconv> <iosfwd> <ratio> <thread>
<chrono> <stop_token> <regex> <tuple>
<codecvt> <istream> <typeindex> <scoped_allocator>
<compare> <iterator> <semaphore> <typeinfo>
<complex> <latch> <set> <type_traits>
<concepts> <limits> <shared_mutex> <unordered_map>
<list> <utility> <unordered_set> <condition_variable>
<coroutine> <locale> <span> <source_location>
<deque> <map> <sstream> <valarray>
<exception> <memory> <stack> <forward_list>
<execution> <version> <stacktrace> <initializer_list>
<filesystem> <mutex> <stdexcept> <memory_resource>
<format> <new>
*/
// + C11 - standard headers
/*
<cassert> <cfenv> <climits> <csetjmp> <cstddef> <cstdlib>
<cctype> <cfloat> <clocale> <csignal> <cstdint> <cstring>
<cerrno> <cinttypes> <cmath> <cstdarg> <cstdio> <ctime>
<cuchar> <cwchar> <cwctype>
*/