boost-date-time – Tarik Billa

How do I convert boost::posix_time::ptime to time_t?

June 7, 2023 by Tarik

Since @icecrime’s method converts twice (ptime uses linear representation internally), I’ve decided to use direct computation instead. Here it is: time_t to_time_t(boost::posix_time::ptime t) { using namespace boost::posix_time; ptime epoch(boost::gregorian::date(1970,1,1)); time_duration::sec_type x = (t – epoch).total_seconds(); // … check overflow here … return time_t(x); } EDIT: Thanks @jaaw for bringing this to my attention. Since boost … Read more

Performance of dynamic_cast?

April 26, 2023 by Tarik

Firstly, you need to measure the performance over a lot more than just a few iterations, as your results will be dominated by the resolution of the timer. Try e.g. 1 million+, in order to build up a representative picture. Also, this result is meaningless unless you compare it against something, i.e. doing the equivalent … Read more

How to parse date/time from string?

March 29, 2023 by Tarik

Although I don’t know how to format a single-digit month input in boost, I can do it after the two-digit edit: #include <iostream> #include <boost/date_time.hpp> namespace bt = boost::posix_time; const std::locale formats[] = { std::locale(std::locale::classic(),new bt::time_input_facet(“%Y-%m-%d %H:%M:%S”)), std::locale(std::locale::classic(),new bt::time_input_facet(“%Y/%m/%d %H:%M:%S”)), std::locale(std::locale::classic(),new bt::time_input_facet(“%d.%m.%Y %H:%M:%S”)), std::locale(std::locale::classic(),new bt::time_input_facet(“%Y-%m-%d”))}; const size_t formats_n = sizeof(formats)/sizeof(formats[0]); std::time_t pt_to_time_t(const bt::ptime& pt) { … Read more