Clang has limited constexpr support

e.g. cannot use `static_cast` so FlashString needs some fudging to get it to compile. Also clang doesn't support constexpr math (yet) so workaround that.
SmingHub · Apr 19, 2024 · 758751a · 758751a
1 parent 66a1dc3
commit 758751a
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Showing 2 changed files with 15 additions and 6 deletions.
diff --git a/Sming/Components/FlashString b/Sming/Components/FlashString
diff --git a/Sming/Core/NanoTime.h b/Sming/Core/NanoTime.h
@@ -38,6 +38,15 @@
 
 namespace NanoTime
 {
+constexpr uint64_t round_ce(double v)
+{
+#ifdef __clang__
+	return uint64_t(v + 0.5);
+#else
+	return round(v);
+#endif
+}
+
 /**
  * @brief Identify units for a scalar quantity of time
  * @note Ordered in increasing unit size, e.g. days > seconds
@@ -242,7 +251,7 @@ template <uint64_t time, Unit unitsFrom, Unit unitsTo,
 		  typename R = std::ratio_divide<UnitTickRatio<unitsTo>, UnitTickRatio<unitsFrom>>>
 constexpr uint64_t convert()
 {
-	return ({ round(double(time) * R::num / R::den); });
+	return ({ round_ce(double(time) * R::num / R::den); });
 }
 
 /**
@@ -504,7 +513,7 @@ template <class Clock_, Unit unit_, uint64_t time_> struct TimeConst {
 	 */
 	static constexpr uint64_t ticks()
 	{
-		return round(double(time_) * TicksPerUnit::num / TicksPerUnit::den);
+		return round_ce(double(time_) * TicksPerUnit::num / TicksPerUnit::den);
 	}
 
 	/**
@@ -522,7 +531,7 @@ template <class Clock_, Unit unit_, uint64_t time_> struct TimeConst {
 	 */
 	static constexpr uint64_t clockTime()
 	{
-		return round(double(ticks()) * TicksPerUnit::den / TicksPerUnit::num);
+		return round_ce(double(ticks()) * TicksPerUnit::den / TicksPerUnit::num);
 	}
 
 	/**
@@ -583,8 +592,8 @@ template <class Clock_, uint64_t ticks_> struct TicksConst {
 
 	template <Unit unit>
 	using TimeConst = TimeConst<Clock, unit,
-								TimeType(round(double(ticks_) * Clock::template TicksPerUnit<unit>::den /
-											   Clock::template TicksPerUnit<unit>::num))>;
+								TimeType(round_ce(double(ticks_) * Clock::template TicksPerUnit<unit>::den /
+												  Clock::template TicksPerUnit<unit>::num))>;
 
 	/**
 	 * @brief Get the time for the tick count in a specific time unit
+3 −3		src/include/FlashString/Array.hpp
+4 −6		src/include/FlashString/Map.hpp
+5 −1		src/include/FlashString/Object.hpp
+1 −1		src/include/FlashString/String.hpp
+4 −4		src/include/FlashString/Vector.hpp
+111 −0		src/include/FlashString/config.hpp
+22 −0		tools/genm.py