TOML++ C++20/C++14 date support #291
Description
Firstly thankyou for TOML++ it is a pleasure to work with !!!
Is your feature request related to a problem? Please describe.
for my simple use of toml files all values parse/serialize neatly except dates. Internally I am using std::chrono::time_point which are a bit of a pain to work with TOML, whilst one can use the old c structs or floor math the amount of generated boilerplate code is tedious and repetitive. See parsing and serializing code below.
Describe the solution you'd like
toml::node::value_or that can return a std::chrono::time_point
Additional constructors for toml::date_time / toml::date / toml::time taking c++20 year_month_day and hh_mm_ss respectively.
c++14 support available if using the library version HowardHinnant date
Additional context
// parse toml
toml::date_time date_time = account_tbl["timestamp"].value_or(
toml::date_time(toml::date(1970, 1, 1)));
using namespace std::chrono;
auto tpt = sys_days{year{date_time.date.year} / date_time.date.month /
date_time.date.day} +
hours(date_time.time.hour) + minutes(date_time.time.minute) +
seconds(date_time.time.second);
// serialize to toml
using namespace std::chrono;
// Get a local time_point with system_clock::duration precision
auto now = zoned_time{current_zone(), system_clock::now()}.get_local_time();
// Get a local time_point with days precision
auto ld = floor<days>(now);
// Convert local days-precision time_point to a local {y, m, d} calendar
year_month_day ymd{ld};
// Split time since local midnight into {h, m, s, subseconds}
hh_mm_ss hms{now - ld};
int year{ymd.year()};
int month = unsigned{ymd.month()};
int day = unsigned{ymd.day()};
int hour = hms.hours().count();
int minute = hms.minutes().count();
int second = hms.seconds().count();
auto d = toml::date(year, month, day);
auto t = toml::time(hour, minute, second);
auto timestamp = toml::date_time(d,t);