c++20. clock chrono API. STL + format

[LukashonakV]

Hi @Alexays ,
This PR is created in order to fully switch clock module to use standard chrono library + format library in c++20. date library by @HowardHinnant has been taken into standard in C++20. STL format library supports chrono now.
So clock module under C++20 now no more using fmt library and construct necessary information using STL.
One more major change: clock module is fully rewritten and as a base is using TZ(zoned time). It should minimize time conversion between local and zoned time.
Structure of the helper include/util/date.hpp now provides compile time switching between
"date/tz.h" + "fmt/chrono.h" <-> <chrono> + <format>
timezoned_time_list placeholder now is renamed to tz_list . This change is attracted in man page too.
+ it should solve any issues during compilation when compiler gets ambiguous errors of the date/format functions

---

This PR is also a prerequisite to start digging into different calendar implementation (what is raised in #2260)

[LukashonakV]

Even clang CI has failed (due to timeout reason) in my branch it looks OK
c++20. clock chrono API. STL + format #239

[Artturin]

We got a failure in nixpkgs-wayland

In file included from ../include/modules/clock.hpp:4,
                 from ../src/modules/clock.cpp:1:
../include/util/date.hpp:34:26: warning: literal operator suffixes not preceded by '_' are reserved for future standardization [-Wliteral-suffix]
   34 | constexpr decltype(auto) operator""d(unsigned long long d) noexcept {
      |                          ^~~~~~~~
../src/modules/clock.cpp: In member function 'const std::string waybar::modules::Clock::get_calendar(const date::year_month_day&, const date::year_month_day&, const date::time_zone*)':
../src/modules/clock.cpp:323:43: error: cannot bind non-const lvalue reference of type 'date::zoned_time<std::chrono::duration<long int> >&' to an rvalue of type 'date::zoned_seconds' {aka 'date::zoned_time<std::chrono::duration<long int> >'}
  323 |                               (line == 2) ? zoned_seconds{tz, local_days{ymTmp / 1}}
      |                               ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  324 |                                           : zoned_seconds{tz, local_days{cldGetWeekForLine(
      |                                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  325 |                                                                   ymTmp, firstdow, line)}}))
      |                                                                   ~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/format.h:49,
                 from ../include/util/date.hpp:9:
/nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/core.h:1824:35: note:   initializing argument 1 of 'constexpr fmt::v10::format_arg_store<Context, typename std::remove_cv<typename std::remove_reference<T>::type>::type ...> fmt::v10::make_format_args(T& ...) [with Context = basic_format_context<appender, char>; T = {date::zoned_time<std::chrono::duration<long int, std::ratio<1, 1> >, const date::time_zone*>}]'
 1824 | constexpr auto make_format_args(T&... args)
      |                                 ~~^~~~~~~~
../src/modules/clock.cpp:345:43: error: cannot bind non-const lvalue reference of type 'date::zoned_time<std::chrono::duration<long int> >&' to an rvalue of type 'date::zoned_seconds' {aka 'date::zoned_time<std::chrono::duration<long int> >'}
  345 |                               (line == 2) ? zoned_seconds{tz, local_days{ymTmp / 1}}
      |                               ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  346 |                                           : zoned_seconds{tz, local_days{cldGetWeekForLine(
      |                                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  347 |                                                                   ymTmp, firstdow, line)}}));
      |                                                                   ~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/core.h:1824:35: note:   initializing argument 1 of 'constexpr fmt::v10::format_arg_store<Context, typename std::remove_cv<typename std::remove_reference<T>::type>::type ...> fmt::v10::make_format_args(T& ...) [with Context = basic_format_context<appender, char>; T = {date::zoned_time<std::chrono::duration<long int, std::ratio<1, 1> >, const date::time_zone*>}]'
 1824 | constexpr auto make_format_args(T&... args)
      |                                 ~~^~~~~~~~
../src/modules/clock.cpp:356:89: error: cannot bind non-const lvalue reference of type 'std::__cxx11::basic_string<char>&' to an rvalue of type 'std::__cxx11::basic_ostringstream<char>::__string_type' {aka 'std::__cxx11::basic_string<char>'}
  356 |         tmp << fmt_lib::vformat(locale_, fmtMap_[line], fmt_lib::make_format_args(os.str()));
      |                                                                                   ~~~~~~^~
/nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/core.h:1824:35: note:   initializing argument 1 of 'constexpr fmt::v10::format_arg_store<Context, typename std::remove_cv<typename std::remove_reference<T>::type>::type ...> fmt::v10::make_format_args(T& ...) [with Context = basic_format_context<appender, char>; T = {std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >}]'
 1824 | constexpr auto make_format_args(T&... args)
      |                                 ~~^~~~~~~~
../src/modules/clock.cpp:367:78: error: cannot bind non-const lvalue reference of type 'std::__cxx11::basic_string<char>&' to an rvalue of type 'std::__cxx11::basic_ostringstream<char>::__string_type' {aka 'std::__cxx11::basic_string<char>'}
  367 |       fmt_lib::vformat(locale_, fmtMap_[2], fmt_lib::make_format_args(tmp.str())),
      |                                                                       ~~~~~~~^~
/nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/core.h:1824:35: note:   initializing argument 1 of 'constexpr fmt::v10::format_arg_store<Context, typename std::remove_cv<typename std::remove_reference<T>::type>::type ...> fmt::v10::make_format_args(T& ...) [with Context = basic_format_context<appender, char>; T = {std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >}]'
 1824 | constexpr auto make_format_args(T&... args)
      |                                 ~~^~~~~~~~
../src/modules/clock.cpp:369:83: error: cannot bind non-const lvalue reference of type 'std::__cxx11::basic_string<char>&' to an rvalue of type 'std::__cxx11::basic_string<char>'
  369 |       fmt_lib::vformat(locale_, fmtMap_[3], fmt_lib::make_format_args(date::format("{:L%e}", d))));
      |                                                                       ~~~~~~~~~~~~^~~~~~~~~~~~~
/nix/store/frlcc137wnrld52w9xdrdcs09chkprlr-fmt-10.1.1-dev/include/fmt/core.h:1824:35: note:   initializing argument 1 of 'constexpr fmt::v10::format_arg_store<Context, typename std::remove_cv<typename std::remove_reference<T>::type>::type ...> fmt::v10::make_format_args(T& ...) [with Context = basic_format_context<appender, char>; T = {std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >}]'
 1824 | constexpr auto make_format_args(T&... args)
      |                                 ~~^~~~~~~~
[194/196] Compiling C++ object test/waybar_test.p/date.cpp.o
In file included from ../test/date.cpp:1:
../include/util/date.hpp:34:26: warning: literal operator suffixes not preceded by '_' are reserved for future standardization [-Wliteral-suffix]
   34 | constexpr decltype(auto) operator""d(unsigned long long d) noexcept {
      |                          ^~~~~~~~
ninja: build stopped: subcommand failed.

[LukashonakV]

I'll check soon

[LukashonakV]

Hi @Artturin , can you check again please. See #2668

[apiraino]

Commit 86a3898 broke the parsing of {timezoned_time_list} that was introduced in #1333 and replaced that with {tz_list}.

Not a big deal, but it would be nice to mention breaking changes somewhere in the changelog. I have updated the wiki page about the clock.

cc: @Alexays