11#if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201510L
17 using std::chrono::abs;
30 template <
class Rep,
class Period>
31 constexpr typename std::enable_if<std::numeric_limits<Rep>::is_signed,
32 std::chrono::duration<Rep, Period>>::type
33 abs(std::chrono::duration<Rep, Period> d)
35 return d >= d.zero() ? d : -d;
constexpr std::enable_if< std::numeric_limits< Rep >::is_signed, std::chrono::duration< Rep, Period > >::type abs(std::chrono::duration< Rep, Period > d)