Add function to convert a time_point in a string

Signed-off-by: ahcorde <[email protected]>

include/ignition/math/Helpers.hh

@@ -23,6 +23,8 @@
 #include <limits>
 #include <string>
 #include <iostream>
+#include <sstream>
+#include <iomanip>
 #include <vector>
 #include <tuple>
 #include <utility>
@@ -771,6 +773,48 @@ namespace ignition
  return {s.count(), ns.count()};
  }
 
+ // TODO(anyone): Replace this with std::chrono::days. This will exist in C++-20
+ typedef std::chrono::duration<long int, std::ratio<86400>> days;
+
+ /// \brief break down durations
+ /// \param[in] d Duration to breaw down
+ /// \return A tuple based on the durations specified
+ template<class...Durations, class DurationIn>
+ std::tuple<Durations...> break_down_durations( DurationIn d ) {
+ std::tuple<Durations...> retval;
+ using discard=int[];
+ (void)discard{0,(void((
+ (std::get<Durations>(retval) = std::chrono::duration_cast<Durations>(d)),
+ (d -= std::chrono::duration_cast<DurationIn>(std::get<Durations>(retval)))
+ )),0)...};
+ return retval;
+ }
+
+ /// \brief Convert a std::chrono::steady_clock::duration to a string
+ /// \param[in] _point The std::chrono::system_clock::time_point to convert.
+ /// \return A string formatted with the time_point
+ inline std::string timePointToString(
+ const std::chrono::system_clock::time_point &_point)
+ {
+ auto duration = _point - std::chrono::system_clock::from_time_t(0);
+ auto clean_duration = break_down_durations<days,
+ std::chrono::hours,
+ std::chrono::minutes,
+ std::chrono::seconds,
+ std::chrono::milliseconds>(duration);
+ std::ostringstream output_string;
+ output_string << std::get<0>(clean_duration).count() << " "
+ << std::setw(2) << std::setfill('0')
+ << std::get<1>(clean_duration).count() << ":"
+ << std::setw(2) << std::setfill('0')
+ << std::get<2>(clean_duration).count() << ":"
+ << std::setw(2) << std::setfill('0')
+ << std::setprecision(3)
+ << std::get<3>(clean_duration).count() +
+ std::get<4>(clean_duration).count()/1000.0;
+ return output_string.str();
+ }
+
  // Degrade precision on Windows, which cannot handle 'long double'
  // values properly. See the implementation of Unpair.
  // 32 bit ARM processors also define 'long double' to be the same