Signed-off-by: Stefan Weil <sw@weilnetz.de>

works only if all named arguments are UDL-based

* Add support for subsecond printing for std::chrono::duration according to the c++20 standard

* Remove assert test that overflows intmax_t

* * Hopefully fix int64_t to int32_t conversion errors.
* Allow proper Duration::rep type to propagate via template argument deduction

* * Hopefully fix int64_t to int32_t conversion errors.
* Allow proper Duration::rep type to propagate via template argument deduction

* Fix sign conversion (-Wsign-conversion) warning treated as error in num_digits()

* Format chrono.h with clang-format

* Remove extra forward slash in doxygen style comment
Co-authored-by: Victor Zverovich <victor.zverovich@gmail.com>

* Apply all suggestions from GitHub, except for replacing the utility subsecond_helper class with a function

* * Move logic of handling subseconds from utility class to function with name write_fractional_seconds()
* Revert write(Rep value, int width) function to previous state

* Fix -Wshadow warning

* Remove unsued get_subseconds() function, its logic has been moved to write_fractional_seconds()

* Change comment from lowercase int to uppercase Int

* Simplify test check

* Integrate suggested changes

* Remove static from detail functions, they are no longer member functions of a class and static is unnecessary.
* Change comment from "amount" to "number"
Co-authored-by: Victor Zverovich <victor.zverovich@gmail.com>

* Move fmt::detail::formatbuf to format.h

* Replace std::basic_ostringstream to std::basic_ostream with custom formatbuf

* Use tm.tm_zone

resolves https://github.com/fmtlib/fmt/issues/2627

* fix int -> uint warning

* change unsigned int to mode_t

* undef + warn uint -> ushort loss presision

* fix mode_t

* mode_t in detail
Co-authored-by: Acretock <George.Goncharov@finch-xr.com>

* FMT_STRING supports C++14 and no-op in C++11

* Move requirement to the end. Modify description.

* Make MSVC use [[nodiscard]]
* Uniformly detect attributes for __cplusplus and _MSVC_LANG

Before adding the format checker, the mainline should be clean, to
avoid false failures.

This prevents accidentally writing fmt::format when fmt::print was
intended. Other than running tests, there's not a good use case for
discarding the formatted output.

Added src directory to link