[core] Polyfill std::chrono::abs

2016-01-21 13:03:03 -08:00
parent cef5c331fe
commit fa894d7cbc
2 changed files with 9 additions and 3 deletions
--- a/include/mbgl/util/chrono.hpp
+++ b/include/mbgl/util/chrono.hpp
@@ -53,6 +53,14 @@ std::string iso8601(SystemTimePoint);

 SystemTimePoint parseTimePoint(const char *);

+// C++17 polyfill
+template <class Rep, class Period, class = std::enable_if_t<
+   std::chrono::duration<Rep, Period>::min() < std::chrono::duration<Rep, Period>::zero()>>
+constexpr std::chrono::duration<Rep, Period> abs(std::chrono::duration<Rep, Period> d)
+{
+    return d >= d.zero() ? d : -d;
+}
+
 } // namespace util

 } // namespace mbgl