Would be nice to include the new rounding functions in chrono in C++17

[UPC-PaalDriveklepp]

floor(std::chrono::duration)(C++17)	converts a duration to another, rounding down(function template)
ceil(std::chrono::duration)(C++17)	converts a duration to another, rounding up(function template)
round(std::chrono::duration)(C++17)	converts a duration to another, rounding to nearest, ties to even(function template)
abs(std::chrono::duration)(C++17)	obtains the absolute value of the duration(function template)

floor(std::chrono::duration)

(C++17)

converts a duration to another, rounding down
(function template)
ceil(std::chrono::duration)

(C++17)

converts a duration to another, rounding up
(function template)
round(std::chrono::duration)

(C++17)

converts a duration to another, rounding to nearest, ties to even
(function template)
abs(std::chrono::duration)

(C++17)

obtains the absolute value of the duration
(function template)