add utils for magnitudes

Author: planetchili

IntelPresentMon/CommonUtilities/Math.h

@@ -21,4 +21,36 @@ namespace pmon::util
 	{
 		return (a - b) < CommonEpsilon(a, b);
 	}
+	enum class MagnitudePrefix
+	{
+		Base,
+		Kilo,
+		Kibi,
+		Mega,
+		Mebi,
+		Giga,
+		Gibi,
+	};
+	constexpr double GetMagnitudeFactor(MagnitudePrefix prefix)
+	{
+		switch (prefix) {
+		case MagnitudePrefix::Base: return 1.;
+		case MagnitudePrefix::Kilo: return 1'000.;
+		case MagnitudePrefix::Kibi: return 1'024.;
+		case MagnitudePrefix::Mega: return 1'000'000.;
+		case MagnitudePrefix::Mebi: return 1'048'576.;
+		case MagnitudePrefix::Giga: return 1'000'000'000.;
+		case MagnitudePrefix::Gibi: return 1'073'741'824.;
+		default: return 0.;
+		}
+	}
+	template<typename From, typename To = From>
+	To ConvertMagnitudePrefix(From from, MagnitudePrefix fromPrefix, MagnitudePrefix toPrefix)
+	{
+		auto fromExtended = double(from);
+		const auto srcFactor = GetMagnitudeFactor(fromPrefix);
+		const auto dstFactor = GetMagnitudeFactor(toPrefix);
+		const auto conversionFactor = srcFactor / dstFactor;
+		return To(fromExtended * conversionFactor);
+	}
 }