diff --git a/CMakeLists.txt b/CMakeLists.txt
index 72a7897de61..c408073eeb1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1174,6 +1174,7 @@ add_library(mixxx-lib STATIC EXCLUDE_FROM_ALL
   src/util/fileaccess.cpp
   src/util/fileinfo.cpp
   src/util/filename.cpp
+  src/util/font.cpp
   src/util/imagefiledata.cpp
   src/util/imagefiledata.cpp
   src/util/imageutils.cpp
@@ -1200,7 +1201,6 @@ add_library(mixxx-lib STATIC EXCLUDE_FROM_ALL
   src/util/tapfilter.cpp
   src/util/task.cpp
   src/util/taskmonitor.cpp
-  src/util/threadcputimer.cpp
   src/util/time.cpp
   src/util/timer.cpp
   src/util/valuetransformer.cpp
@@ -1470,7 +1470,6 @@ set(MIXXX_LIB_PRECOMPILED_HEADER
   src/util/taskmonitor.h
   src/util/thread_affinity.h
   src/util/thread_annotations.h
-  src/util/threadcputimer.h
   src/util/time.h
   src/util/timer.h
   src/util/trace.h
diff --git a/src/analyzer/analyzerwaveform.h b/src/analyzer/analyzerwaveform.h
index 4771cc50993..ccdafd5242d 100644
--- a/src/analyzer/analyzerwaveform.h
+++ b/src/analyzer/analyzerwaveform.h
@@ -46,16 +46,16 @@ struct WaveformStride {
     inline void store(WaveformData* data) {
         for (int i = 0; i < ChannelCount; ++i) {
             WaveformData& datum = *(data + i);
-            datum.filtered.all = static_cast<unsigned char>(math_min(255.0,
+            datum.filtered.all = static_cast<unsigned char>(std::min(255.0,
                     m_postScaleConversion * m_overallData[i] + 0.5));
-            datum.filtered.low = static_cast<unsigned char>(math_min(255.0,
+            datum.filtered.low = static_cast<unsigned char>(std::min(255.0,
                     m_postScaleConversion * m_filteredData[i][Low] + 0.5));
-            datum.filtered.mid = static_cast<unsigned char>(math_min(255.0,
+            datum.filtered.mid = static_cast<unsigned char>(std::min(255.0,
                     m_postScaleConversion * m_filteredData[i][Mid] + 0.5));
-            datum.filtered.high = static_cast<unsigned char>(math_min(255.0,
+            datum.filtered.high = static_cast<unsigned char>(std::min(255.0,
                     m_postScaleConversion * m_filteredData[i][High] + 0.5));
             for (int stemIdx = 0; stemIdx < m_stemCount; stemIdx++) {
-                datum.stems[stemIdx] = static_cast<unsigned char>(math_min(255.0,
+                datum.stems[stemIdx] = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_stemData[i][stemIdx] + 0.5));
             }
         }
@@ -78,17 +78,17 @@ struct WaveformStride {
         if (m_averageDivisor) {
             for (int i = 0; i < ChannelCount; ++i) {
                 WaveformData& datum = *(data + i);
-                datum.filtered.all = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.all = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_averageOverallData[i] / m_averageDivisor + 0.5));
-                datum.filtered.low = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.low = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_averageFilteredData[i][Low] /
                                         m_averageDivisor +
                                 0.5));
-                datum.filtered.mid = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.mid = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_averageFilteredData[i][Mid] /
                                         m_averageDivisor +
                                 0.5));
-                datum.filtered.high = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.high = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_averageFilteredData[i][High] /
                                         m_averageDivisor +
                                 0.5));
@@ -97,13 +97,13 @@ struct WaveformStride {
             // This is the case if The Overview Waveform has more samples than the detailed waveform
             for (int i = 0; i < ChannelCount; ++i) {
                 WaveformData& datum = *(data + i);
-                datum.filtered.all = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.all = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_overallData[i] + 0.5));
-                datum.filtered.low = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.low = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_filteredData[i][Low] + 0.5));
-                datum.filtered.mid = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.mid = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_filteredData[i][Mid] + 0.5));
-                datum.filtered.high = static_cast<unsigned char>(math_min(255.0,
+                datum.filtered.high = static_cast<unsigned char>(std::min(255.0,
                         m_postScaleConversion * m_filteredData[i][High] + 0.5));
             }
         }
diff --git a/src/database/schemamanager.cpp b/src/database/schemamanager.cpp
index a17dc47e9a3..5f0ef182918 100644
--- a/src/database/schemamanager.cpp
+++ b/src/database/schemamanager.cpp
@@ -1,11 +1,14 @@
 #include "database/schemamanager.h"
 
+#include <QDomElement>
+#include <QDomNode>
+#include <QDomNodeList>
+
 #include "util/assert.h"
 #include "util/db/fwdsqlquery.h"
 #include "util/db/sqltransaction.h"
 #include "util/logger.h"
 #include "util/math.h"
-#include "util/optional.h"
 #include "util/xml.h"
 
 namespace {
diff --git a/src/effects/backends/builtin/autopaneffect.h b/src/effects/backends/builtin/autopaneffect.h
index 50dd2f7d228..4994ea0e1a7 100644
--- a/src/effects/backends/builtin/autopaneffect.h
+++ b/src/effects/backends/builtin/autopaneffect.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <QMap>
+#include <cmath>
 
 #include "effects/backends/effectprocessor.h"
 #include "engine/filters/enginefilterpansingle.h"
@@ -13,27 +14,25 @@
 // somewhere else (I hear clicks when I change the period of flanger for example).
 class RampedSample {
   public:
-    inline RampedSample()
+    constexpr RampedSample()
             : ramped(false),
               maxDifference(1.0f),
               currentValue(0),
               initialized(false) {
     }
 
-    virtual ~RampedSample(){};
-
-    inline void setRampingThreshold(const float newMaxDifference) {
+    constexpr void setRampingThreshold(float newMaxDifference) {
         maxDifference = newMaxDifference;
     }
 
-    inline void setWithRampingApplied(const float newValue) {
+    constexpr void setWithRampingApplied(float newValue) {
         if (!initialized) {
             currentValue = newValue;
             initialized = true;
         } else {
             float difference = newValue - currentValue;
-            if (fabs(difference) > maxDifference) {
-                currentValue += difference / fabs(difference) * maxDifference;
+            if (abs(difference) > maxDifference) {
+                currentValue += difference / abs(difference) * maxDifference;
                 ramped = true;
             } else {
                 currentValue = newValue;
@@ -42,7 +41,7 @@ class RampedSample {
         }
     }
 
-    inline operator float() {
+    constexpr operator float() {
         return currentValue;
     }
 
diff --git a/src/effects/backends/builtin/compressoreffect.cpp b/src/effects/backends/builtin/compressoreffect.cpp
index cea9b622f4b..311256fd2ad 100644
--- a/src/effects/backends/builtin/compressoreffect.cpp
+++ b/src/effects/backends/builtin/compressoreffect.cpp
@@ -1,5 +1,7 @@
 #include "effects/backends/builtin/compressoreffect.h"
 
+#include "util/math.h"
+
 namespace {
 // Auto make up time is empirically selected parameter, which is good enough for most cases
 constexpr double defaultMakeUpAttackMs = 150;
diff --git a/src/effects/backends/builtin/distortioneffect.h b/src/effects/backends/builtin/distortioneffect.h
index 70dd90cae16..00e077dc7d6 100644
--- a/src/effects/backends/builtin/distortioneffect.h
+++ b/src/effects/backends/builtin/distortioneffect.h
@@ -91,7 +91,7 @@ class DistortionEffect : public EffectProcessorImpl<DistortionGroupState> {
         pState->m_previousMakeUpGain = gain;
 
         // Crossfade
-        CSAMPLE crossfadeParam = math_min(driveParam / ModeParams::crossfadeEndParam, 1.f);
+        CSAMPLE crossfadeParam = std::min(driveParam / ModeParams::crossfadeEndParam, 1.f);
         SampleUtil::applyRampingGain(pOutput,
                 pState->m_crossfadeParameter,
                 crossfadeParam,
diff --git a/src/effects/backends/builtin/phasereffect.cpp b/src/effects/backends/builtin/phasereffect.cpp
index 709d23d09a8..74f0c4b4e6f 100644
--- a/src/effects/backends/builtin/phasereffect.cpp
+++ b/src/effects/backends/builtin/phasereffect.cpp
@@ -2,6 +2,7 @@
 
 #include "effects/backends/effectmanifest.h"
 #include "engine/effects/engineeffectparameter.h"
+#include "util/math.h"
 
 namespace {
 constexpr unsigned int updateCoef = 32;
diff --git a/src/effects/backends/builtin/pitchshifteffect.cpp b/src/effects/backends/builtin/pitchshifteffect.cpp
index 4d5dbd726c5..1df0d7165ae 100644
--- a/src/effects/backends/builtin/pitchshifteffect.cpp
+++ b/src/effects/backends/builtin/pitchshifteffect.cpp
@@ -6,6 +6,7 @@
 
 #include "effects/backends/effectmanifest.h"
 #include "engine/effects/engineeffectparameter.h"
+#include "util/math.h"
 #include "util/sample.h"
 
 namespace {
diff --git a/src/encoder/encodersndfileflac.cpp b/src/encoder/encodersndfileflac.cpp
index 7fb40d8e88f..00637f0b15f 100644
--- a/src/encoder/encodersndfileflac.cpp
+++ b/src/encoder/encodersndfileflac.cpp
@@ -1,6 +1,7 @@
 #include "encoder/encodersndfileflac.h"
 
 #include <QtDebug>
+#include <algorithm>
 
 #include "encoder/encoderflacsettings.h"
 
@@ -13,14 +14,14 @@ void convertFloat32ToIntFormat(int* pDest, const CSAMPLE* pSrc, SINT numSamples,
     if (format & SF_FORMAT_PCM_16) {
         // note: LOOP VECTORIZED"
         for (SINT i = 0; i < numSamples; ++i) {
-            pDest[i] = static_cast<int>(math_clamp(pSrc[i] * kFloatToIntConversionFactor,
+            pDest[i] = static_cast<int>(std::clamp(pSrc[i] * kFloatToIntConversionFactor,
                     static_cast<CSAMPLE>(static_cast<int>(INT_MIN & 0xFFFF0000)),
                     static_cast<CSAMPLE>(static_cast<int>(INT_MAX & 0xFFFF0000))));
         }
     } else if (format & SF_FORMAT_PCM_24) {
         // note: LOOP VECTORIZED"
         for (SINT i = 0; i < numSamples; ++i) {
-            pDest[i] = static_cast<int>(math_clamp(pSrc[i] * kFloatToIntConversionFactor,
+            pDest[i] = static_cast<int>(std::clamp(pSrc[i] * kFloatToIntConversionFactor,
                     static_cast<CSAMPLE>(static_cast<int>(INT_MIN & 0xFFFFFF00)),
                     static_cast<CSAMPLE>(static_cast<int>(INT_MAX & 0xFFFFFF00))));
         }
@@ -62,7 +63,7 @@ void EncoderSndfileFlac::encodeBuffer(const CSAMPLE* pBuffer, const int iBufferS
     if (m_pClampBuffer) {
         SINT numSamplesLeft = iBufferSize;
         while (numSamplesLeft > 0) {
-            const SINT numSamplesToWrite = math_min(numSamplesLeft, kEncBufferSize);
+            const SINT numSamplesToWrite = std::min(numSamplesLeft, kEncBufferSize);
             convertFloat32ToIntFormat(m_pClampBuffer.get(),
                     pBuffer,
                     numSamplesToWrite,
diff --git a/src/engine/controls/ratecontrol.cpp b/src/engine/controls/ratecontrol.cpp
index 8e1c065ccda..e036eb16ab8 100644
--- a/src/engine/controls/ratecontrol.cpp
+++ b/src/engine/controls/ratecontrol.cpp
@@ -165,19 +165,8 @@ RateControl::RateControl(const QString& group,
 
 
     m_pJog = new ControlObject(ConfigKey(group, "jog"));
-    m_pJogFilter = new Rotary();
     // FIXME: This should be dependent on sample rate/block size or something
-    m_pJogFilter->setFilterLength(25);
-
-//     // Update Internal Settings
-//     // Set Pitchbend Mode
-//     m_eRateRampMode = static_cast<RampMode>(
-//         getConfig()->getValue(ConfigKey("[Controls]","RateRamp"),
-//                               static_cast<int>(RampMode::Stepping)));
-
-//     // Set the Sensitivity
-//     m_iRateRampSensitivity =
-//             getConfig()->getValueString(ConfigKey("[Controls]","RateRampSensitivity")).toInt();
+    m_pJogFilter = new Rotary(25);
 
     m_pSyncMode = new ControlProxy(group, "sync_mode", this);
 }
diff --git a/src/engine/enginesidechaincompressor.cpp b/src/engine/enginesidechaincompressor.cpp
index 7ff4cb1b043..829b72fbc4a 100644
--- a/src/engine/enginesidechaincompressor.cpp
+++ b/src/engine/enginesidechaincompressor.cpp
@@ -1,6 +1,8 @@
+#include "engine/enginesidechaincompressor.h"
+
 #include <QtDebug>
 
-#include "engine/enginesidechaincompressor.h"
+#include "util/assert.h"
 
 EngineSideChainCompressor::EngineSideChainCompressor(const QString& group)
         : m_compressRatio(1.0),
diff --git a/src/preferences/broadcastprofile.cpp b/src/preferences/broadcastprofile.cpp
index b2d354561ad..e2e2ab2ede0 100644
--- a/src/preferences/broadcastprofile.cpp
+++ b/src/preferences/broadcastprofile.cpp
@@ -1,3 +1,8 @@
+#include "preferences/broadcastprofile.h"
+
+#include <QDomDocument>
+#include <QDomElement>
+#include <QDomNode>
 #include <QEventLoop>
 #include <QFile>
 #include <QFileInfo>
@@ -16,7 +21,6 @@ using namespace QKeychain;
 #endif // __QTKEYCHAIN__
 
 #include "broadcast/defs_broadcast.h"
-#include "broadcastprofile.h"
 #include "defs_urls.h"
 #include "errordialoghandler.h"
 #include "moc_broadcastprofile.cpp"
diff --git a/src/skin/legacy/legacyskinparser.cpp b/src/skin/legacy/legacyskinparser.cpp
index 4f401341259..09b7306cf43 100644
--- a/src/skin/legacy/legacyskinparser.cpp
+++ b/src/skin/legacy/legacyskinparser.cpp
@@ -10,6 +10,7 @@
 #include <QtGlobal>
 
 #include "control/controlobject.h"
+#include "control/controlpushbutton.h"
 #include "controllers/controllerlearningeventfilter.h"
 #include "controllers/controllermanager.h"
 #include "controllers/keyboard/keyboardeventfilter.h"
@@ -2306,7 +2307,9 @@ void LegacySkinParser::setupConnections(const QDomNode& node, WBaseWidget* pWidg
         ValueTransformer* pTransformer = nullptr;
         QDomElement transform = m_pContext->selectElement(con, "Transform");
         if (!transform.isNull()) {
-            pTransformer = ValueTransformer::parseFromXml(transform, *m_pContext);
+            pTransformer =
+                    ValueTransformer::parseFromXml(transform, *m_pContext)
+                            .release(); // TODO don't leak here
         }
 
         QString property;
diff --git a/src/sources/audiosource.cpp b/src/sources/audiosource.cpp
index 2b3d7525fee..6d4df8397b4 100644
--- a/src/sources/audiosource.cpp
+++ b/src/sources/audiosource.cpp
@@ -193,7 +193,7 @@ bool AudioSource::verifyReadable() {
     // Counterexample: The broken FAAD version 2.9.1 is able to open a file
     // but then fails to decode any sample frames.
     const SINT numSampleFrames =
-            math_min(kVerifyReadableMaxFrameCount, frameIndexRange().length());
+            std::min(kVerifyReadableMaxFrameCount, frameIndexRange().length());
     SampleBuffer sampleBuffer(
             m_signalInfo.frames2samples(numSampleFrames));
     WritableSampleFrames writableSampleFrames(
diff --git a/src/sources/readaheadframebuffer.cpp b/src/sources/readaheadframebuffer.cpp
index 8613aac9c3d..838c2434728 100644
--- a/src/sources/readaheadframebuffer.cpp
+++ b/src/sources/readaheadframebuffer.cpp
@@ -288,7 +288,7 @@ WritableSampleFrames ReadAheadFrameBuffer::consumeAndFillBuffer(
     // Detect and handle unexpected discontinuities: Overlap
     if (inputRange.start() < outputRange.start()) {
         const auto overlapRange = IndexRange::between(
-                math_max(inputRange.start(), minOutputIndex),
+                std::max(inputRange.start(), minOutputIndex),
                 outputRange.start());
         DEBUG_ASSERT(
                 overlapRange.orientation() !=
@@ -313,7 +313,7 @@ WritableSampleFrames ReadAheadFrameBuffer::consumeAndFillBuffer(
     }
     if (!isEmpty() && inputRange.start() < writeIndex()) {
         const auto overlapRange = IndexRange::between(
-                math_max(inputRange.start(), readIndex()),
+                std::max(inputRange.start(), readIndex()),
                 writeIndex());
         DEBUG_ASSERT(
                 overlapRange.orientation() !=
@@ -340,7 +340,7 @@ WritableSampleFrames ReadAheadFrameBuffer::consumeAndFillBuffer(
         const auto precedingRange =
                 IndexRange::between(
                         inputRange.start(),
-                        math_min(outputRange.start(), inputRange.end()));
+                        std::min(outputRange.start(), inputRange.end()));
 #if VERBOSE_DEBUG_LOG
         kLogger.debug()
                 << "Discarding input data"
@@ -363,7 +363,7 @@ WritableSampleFrames ReadAheadFrameBuffer::consumeAndFillBuffer(
             const auto gapRange =
                     IndexRange::between(
                             outputRange.start(),
-                            math_min(inputRange.start(), outputRange.end()));
+                            std::min(inputRange.start(), outputRange.end()));
             DEBUG_ASSERT(
                     gapRange.orientation() !=
                     IndexRange::Orientation::Backward);
@@ -390,7 +390,7 @@ WritableSampleFrames ReadAheadFrameBuffer::consumeAndFillBuffer(
         const auto copyableFrameRange =
                 IndexRange::between(
                         outputRange.start(),
-                        math_min(inputRange.end(), outputRange.end()));
+                        std::min(inputRange.end(), outputRange.end()));
         DEBUG_ASSERT(copyableFrameRange.orientation() != IndexRange::Orientation::Backward);
         if (copyableFrameRange.orientation() == IndexRange::Orientation::Forward) {
 #if VERBOSE_DEBUG_LOG
diff --git a/src/util/class.h b/src/util/class.h
index 793a7726faa..7fbc82a1573 100644
--- a/src/util/class.h
+++ b/src/util/class.h
@@ -1,7 +1,11 @@
 #pragma once
 
-// A macro to disallow the copy constructor and operator= functions
-// This should be used in the private: declarations for a class
+// DEPRECATED: Adhere to the rule "the rule of zero" or "the rule of five".
+// See https://en.cppreference.com/w/cpp/language/rule_of_three
+// Rationale: If a class deals with ownership, it should do nothing more and explicitly
+// define the behavior of all special member functions.
+// This macro is sprinkled into lots of big classes and ignores the move-related SMF's.
+// So its common use violates both principles and thus it should not be used anymore!
 #define DISALLOW_COPY_AND_ASSIGN(TypeName) \
     TypeName(const TypeName&) = delete;    \
     void operator=(const TypeName&) = delete;
diff --git a/src/util/compatibility/qatomic.h b/src/util/compatibility/qatomic.h
index 20dc6004e3c..9b140eaf18a 100644
--- a/src/util/compatibility/qatomic.h
+++ b/src/util/compatibility/qatomic.h
@@ -9,24 +9,6 @@
 // Until the minimum required Qt version of Mixxx is increased some utility
 // functions that work independently of the Qt version are needed.
 
-template<typename T>
-inline T atomicLoadAcquire(const QAtomicInteger<T>& atomicInt) {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-    return atomicInt.loadAcquire();
-#else
-    return atomicInt.load();
-#endif
-}
-
-template<typename T>
-inline T* atomicLoadAcquire(const QAtomicPointer<T>& atomicPtr) {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-    return atomicPtr.loadAcquire();
-#else
-    return atomicPtr.load();
-#endif
-}
-
 template<typename T>
 inline T atomicLoadRelaxed(const QAtomicInteger<T>& atomicInt) {
 #if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
@@ -45,15 +27,6 @@ inline T* atomicLoadRelaxed(const QAtomicPointer<T>& atomicPtr) {
 #endif
 }
 
-template<typename T>
-inline void atomicStoreRelaxed(QAtomicInteger<T>& atomicInt, T newValue) {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-    atomicInt.storeRelaxed(newValue);
-#else
-    atomicInt.store(newValue);
-#endif
-}
-
 template<typename T>
 inline void atomicStoreRelaxed(QAtomicPointer<T>& atomicPtr, T* newValue) {
 #if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
diff --git a/src/util/font.cpp b/src/util/font.cpp
new file mode 100644
index 00000000000..26cc6cee894
--- /dev/null
+++ b/src/util/font.cpp
@@ -0,0 +1,84 @@
+#include "util/font.h"
+
+#include <QDir>
+#include <QFontDatabase>
+#include <QString>
+#include <QtDebug>
+
+#include "util/cmdlineargs.h"
+
+namespace {
+
+bool addFont(const QString& path) {
+    int result = QFontDatabase::addApplicationFont(path);
+    if (result == -1) {
+        qWarning() << "Failed to add font:" << path;
+        return false;
+    }
+
+    // In developer mode, spit out all the families / styles / sizes
+    // supported by the new font.
+    if (CmdlineArgs::Instance().getDeveloper()) {
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+        QFontDatabase database;
+#endif
+        QStringList pointSizesStr;
+        const QStringList families = QFontDatabase::applicationFontFamilies(result);
+        for (const QString& family : families) {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+            const QStringList styles = QFontDatabase::styles(family);
+#else
+            const QStringList styles = database.styles(family);
+#endif
+            for (const QString& style : styles) {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+                const QList<int> pointSizes = QFontDatabase::pointSizes(family, style);
+#else
+                const QList<int> pointSizes = database.pointSizes(family, style);
+#endif
+                pointSizesStr.clear();
+                pointSizesStr.reserve(pointSizes.count());
+                for (int point : pointSizes) {
+                    pointSizesStr.append(QString::number(point));
+                }
+                qDebug() << "FONT LOADED family:" << family
+                         << "style:" << style
+                         << "point sizes:" << pointSizesStr.join(",");
+            }
+        }
+    }
+    return true;
+}
+
+} // namespace
+
+void FontUtils::initializeFonts(const QString& resourcePath) {
+    QDir fontsDir(resourcePath);
+    if (!fontsDir.cd("fonts")) {
+#ifdef __LINUX__
+        // If the fonts already have been installed via the package
+        // manager, this is okay. We currently have no way to verify that
+        // though.
+        qDebug()
+#else
+        qWarning()
+#endif
+                << "No fonts directory found in" << resourcePath;
+        return;
+    }
+
+    QList<QFileInfo> files = fontsDir.entryInfoList(
+            QDir::NoDotAndDotDot | QDir::Files | QDir::Readable);
+    for (const QFileInfo& file : files) {
+        const QString& path = file.filePath();
+
+        // Skip text files (e.g. license files). For all others we let Qt tell
+        // us whether the font format is supported since there is no way to
+        // check other than adding.
+        if (path.endsWith(".txt", Qt::CaseInsensitive)) {
+            continue;
+        }
+
+        addFont(path);
+    }
+}
diff --git a/src/util/font.h b/src/util/font.h
index 42bb21f4701..dc47956809f 100644
--- a/src/util/font.h
+++ b/src/util/font.h
@@ -1,86 +1,7 @@
 #pragma once
 
-#include <QFontDatabase>
-#include <QString>
-#include <QtDebug>
-#include <QDir>
+class QString;
 
-#include "util/cmdlineargs.h"
-
-class FontUtils {
-  public:
-    static void initializeFonts(const QString& resourcePath) {
-        QDir fontsDir(resourcePath);
-        if (!fontsDir.cd("fonts")) {
-#ifdef __LINUX__
-            // If the fonts already have been installed via the package
-            // manager, this is okay. We currently have no way to verify that
-            // though.
-            qDebug()
-#else
-            qWarning()
-#endif
-                    << "No fonts directory found in" << resourcePath;
-            return;
-        }
-
-        QList<QFileInfo> files = fontsDir.entryInfoList(
-            QDir::NoDotAndDotDot | QDir::Files | QDir::Readable);
-        foreach (const QFileInfo& file, files) {
-            const QString& path = file.filePath();
-
-            // Skip text files (e.g. license files). For all others we let Qt tell
-            // us whether the font format is supported since there is no way to
-            // check other than adding.
-            if (path.endsWith(".txt", Qt::CaseInsensitive)) {
-                continue;
-            }
-
-            addFont(path);
-        }
-    }
-
-    static bool addFont(const QString& path) {
-        int result = QFontDatabase::addApplicationFont(path);
-        if (result == -1) {
-            qWarning() << "Failed to add font:" << path;
-            return false;
-        }
-
-        // In developer mode, spit out all the families / styles / sizes
-        // supported by the new font.
-        if (CmdlineArgs::Instance().getDeveloper()) {
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-            QFontDatabase database;
-#endif
-            QStringList pointSizesStr;
-            const QStringList families = QFontDatabase::applicationFontFamilies(result);
-            for (const QString& family : families) {
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
-                const QStringList styles = QFontDatabase::styles(family);
-#else
-                const QStringList styles = database.styles(family);
-#endif
-                for (const QString& style : styles) {
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
-                    const QList<int> pointSizes = QFontDatabase::pointSizes(family, style);
-#else
-                    const QList<int> pointSizes = database.pointSizes(family, style);
-#endif
-                    pointSizesStr.clear();
-                    pointSizesStr.reserve(pointSizes.count());
-                    for (int point : pointSizes) {
-                        pointSizesStr.append(QString::number(point));
-                    }
-                    qDebug() << "FONT LOADED family:" << family
-                             << "style:" << style
-                             << "point sizes:" << pointSizesStr.join(",");
-                }
-            }
-        }
-        return true;
-    }
-
-  private:
-    FontUtils() {}
-};
+namespace FontUtils {
+void initializeFonts(const QString& resourcePath);
+} // namespace FontUtils
diff --git a/src/util/readaheadsamplebuffer.cpp b/src/util/readaheadsamplebuffer.cpp
index 5e047d0822d..36ec6dd181d 100644
--- a/src/util/readaheadsamplebuffer.cpp
+++ b/src/util/readaheadsamplebuffer.cpp
@@ -53,7 +53,7 @@ void ReadAheadSampleBuffer::clear() {
 void ReadAheadSampleBuffer::adjustCapacity(SINT capacity) {
     DEBUG_ASSERT_CLASS_INVARIANT_ReadAheadSampleBuffer;
 
-    SINT newCapacity = math_max(readableLength(), capacity);
+    SINT newCapacity = std::max(readableLength(), capacity);
     if (newCapacity != this->capacity()) {
         ReadAheadSampleBuffer tmp(*this, newCapacity);
         swap(tmp);
@@ -65,7 +65,7 @@ void ReadAheadSampleBuffer::adjustCapacity(SINT capacity) {
 SampleBuffer::WritableSlice ReadAheadSampleBuffer::growForWriting(SINT maxWriteLength) {
     DEBUG_ASSERT_CLASS_INVARIANT_ReadAheadSampleBuffer;
 
-    const SINT tailLength = math_min(maxWriteLength, writableLength());
+    const SINT tailLength = std::min(maxWriteLength, writableLength());
     const SampleBuffer::WritableSlice tailSlice(
             m_sampleBuffer, m_readableRange.end(), tailLength);
     m_readableRange.growBack(tailLength);
@@ -77,7 +77,7 @@ SampleBuffer::WritableSlice ReadAheadSampleBuffer::growForWriting(SINT maxWriteL
 SINT ReadAheadSampleBuffer::shrinkAfterWriting(SINT maxShrinkLength) {
     DEBUG_ASSERT_CLASS_INVARIANT_ReadAheadSampleBuffer;
 
-    const SINT shrinkLength = math_min(maxShrinkLength, readableLength());
+    const SINT shrinkLength = std::min(maxShrinkLength, readableLength());
     m_readableRange.shrinkBack(shrinkLength);
     // If the buffer has become empty reset the write head back to the start
     // of the available memory
@@ -92,7 +92,7 @@ SINT ReadAheadSampleBuffer::shrinkAfterWriting(SINT maxShrinkLength) {
 SampleBuffer::ReadableSlice ReadAheadSampleBuffer::shrinkForReading(SINT maxReadLength) {
     DEBUG_ASSERT_CLASS_INVARIANT_ReadAheadSampleBuffer;
 
-    const SINT headLength = math_min(maxReadLength, readableLength());
+    const SINT headLength = std::min(maxReadLength, readableLength());
     const SampleBuffer::ReadableSlice headSlice(
             m_sampleBuffer, m_readableRange.start(), headLength);
     m_readableRange.shrinkFront(headLength);
diff --git a/src/util/regex.h b/src/util/regex.h
index e3c59368d45..73fa32485e5 100644
--- a/src/util/regex.h
+++ b/src/util/regex.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <QtGlobal> // for qt version checking
+
 // QRegularExpression::escape was introduced in Qt 5.15.
 #if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
 #include <QRegularExpression>
@@ -9,21 +11,19 @@
 #include <QStringList>
 #include <QString>
 
-class RegexUtils {
-  public:
-    static QString fileExtensionsRegex(QStringList extensions) {
-        // Escape every extension appropriately
-        for (int i = 0; i < extensions.size(); ++i) {
+namespace RegexUtils {
+
+inline QString fileExtensionsRegex(QStringList extensions) {
+    // Escape every extension appropriately
+    for (int i = 0; i < extensions.size(); ++i) {
 #if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
-            extensions[i] = QRegularExpression::escape(extensions[i]);
+        extensions[i] = QRegularExpression::escape(extensions[i]);
 #else
-            extensions[i] = QRegExp::escape(extensions[i]);
+        extensions[i] = QRegExp::escape(extensions[i]);
 #endif
-        }
-        // Turn the list into a "\\.(jpg|gif|etc)$" style regex string
-        return QString("\\.(%1)$").arg(extensions.join("|"));
     }
+    // Turn the list into a "\\.(jpg|gif|etc)$" style regex string
+    return QStringLiteral("\\.(%1)$").arg(extensions.join('|'));
+}
 
-  private:
-    RegexUtils() {}
-};
+} // namespace RegexUtils
diff --git a/src/util/rescaler.h b/src/util/rescaler.h
index c0d6bb9f367..51460dd8311 100644
--- a/src/util/rescaler.h
+++ b/src/util/rescaler.h
@@ -1,22 +1,17 @@
 #pragma once
 
-class RescalerUtils {
-  public:
+namespace RescalerUtils {
+// converts a value on a linear scale to a 1/x scale staring at 1
+inline double linearToOneByX(double in, double inMin, double inMax, double outMax) {
+    double outRange = outMax - 1;
+    double inRange = inMax - inMin;
+    return outMax / (((inMax - in) / inRange * outRange) + 1);
+}
 
-    // converts a value on a linear scale to a 1/x scale staring at 1
-    static double linearToOneByX(double in, double inMin, double inMax, double outMax) {
-        double outRange = outMax - 1;
-        double inRange = inMax - inMin;
-        return outMax / (((inMax - in) / inRange * outRange) + 1);
-    }
-
-    // converts value on a 1/x scale starting by 1 to a linear scale
-    static double oneByXToLinear(double in, double inMax, double outMin, double outMax) {
-        double outRange = outMax - outMin;
-        double inRange = inMax - 1;
-        return outMax - (((inMax / in) - 1) / inRange * outRange);
-    }
-
-  private:
-    RescalerUtils() {}
-};
+// converts value on a 1/x scale starting by 1 to a linear scale
+inline double oneByXToLinear(double in, double inMax, double outMin, double outMax) {
+    double outRange = outMax - outMin;
+    double inRange = inMax - 1;
+    return outMax - (((inMax / in) - 1) / inRange * outRange);
+}
+}; // namespace RescalerUtils
diff --git a/src/util/rlimit.h b/src/util/rlimit.h
index 1f8b50ea6ec..8030517071f 100644
--- a/src/util/rlimit.h
+++ b/src/util/rlimit.h
@@ -2,11 +2,12 @@
 
 #ifdef __LINUX__
 
-class RLimit {
-  public:
-    static unsigned int getCurRtPrio();
-    static unsigned int getMaxRtPrio();
-    static bool isRtPrioAllowed();
-};
+namespace RLimit {
+
+unsigned int getCurRtPrio();
+unsigned int getMaxRtPrio();
+bool isRtPrioAllowed();
+
+} // namespace RLimit
 
 #endif // __LINUX__
diff --git a/src/util/rotary.cpp b/src/util/rotary.cpp
index 45f3054d91a..63b63e764fe 100644
--- a/src/util/rotary.cpp
+++ b/src/util/rotary.cpp
@@ -1,93 +1,35 @@
 #include "util/rotary.h"
 
-#include <QtDebug>
+#include <numeric>
 
-constexpr int kiRotaryFilterMaxLen = 50;
-
-Rotary::Rotary()
-        : m_iFilterLength(kiRotaryFilterMaxLen),
-          m_iFilterPos(0),
-          m_pFilter(m_iFilterLength),
-          m_dCalibration(1.0),
-          m_dLastValue(0.0),
-          m_iCalibrationCount(0) {
-    for (int i = 0; i < m_iFilterLength; ++i) {
-        m_pFilter[i] = 0.;
-    }
-}
-
-/* Note: There's probably a bug in this function (or this class) somewhere.
-   The filter function seems to be the cause of the "drifting" bug in the Hercules stuff.
-   What happens is that filter() gets called to do some magic to a value that's returned
-   from the Hercules device, and that magic adds "momentum" to it's motion (ie. it doesn't
-   stop dead when you stop spinning the jog wheels.) The problem with this "magic" is that
-   when herculeslinux.cpp passes the filtered value off to the wheel ControlObject (or what
-   have you), the ControlObject's internal value never goes back to zero properly.
-   - Albert (March 13, 2007)
- */
-double Rotary::filter(double dValue) {
-    // Update filter buffer
-    m_pFilter[m_iFilterPos] = dValue/m_dCalibration;
-    m_iFilterPos = (m_iFilterPos+1)%m_iFilterLength;
-
-    double dMagnitude = 0.;
-    for (int i=0; i<m_iFilterLength; i++)
-    {
-        dMagnitude += m_pFilter[i];
+Rotary::index_type Rotary::nextIndex(Rotary::index_type i) {
+    if (++i >= m_filterHistory.size()) {
+        return 0;
     }
-    dMagnitude /= (double)m_iFilterLength;
-    //qDebug() << "filter in " << dValue << ", out " << dMagnitude;
-
-    m_dLastValue = dMagnitude;
-
-    return dMagnitude;
-}
-
-double Rotary::fillBuffer(double dValue) {
-    for (int i=0; i<m_iFilterLength; ++i)
-    {
-        m_pFilter[i] = dValue/m_dCalibration;
-    }
-    return dValue/m_dCalibration;
+    return i;
 }
 
-void Rotary::calibrate(double dValue) {
-    m_dCalibration += dValue;
-    m_iCalibrationCount += 1;
+void Rotary::append(double v) {
+    m_filterHistory[nextIndex(m_headIndex)] = v;
 }
 
-void Rotary::calibrateStart() {
-    // Reset calibration data
-    m_dCalibration = 0.;
-    m_iCalibrationCount = 0;
+double Rotary::calculate() const {
+    return std::accumulate(std::cbegin(m_filterHistory),
+                   std::cend(m_filterHistory),
+                   0) /
+            static_cast<double>(m_filterHistory.size());
 }
 
-double Rotary::calibrateEnd() {
-    m_dCalibration /= (double)m_iCalibrationCount;
-
-    qDebug() << "Calibration " << m_dCalibration << ", count " << m_iCalibrationCount;
-
-    return m_dCalibration;
-}
-
-void Rotary::setCalibration(double c) {
-    m_dCalibration = c;
-}
-
-double Rotary::getCalibration() {
-    return m_dCalibration;
-}
-
-void Rotary::setFilterLength(int i) {
-    if (i > kiRotaryFilterMaxLen) {
-        m_iFilterLength = kiRotaryFilterMaxLen;
-    } else if (i < 1) {
-        m_iFilterLength = 1;
-    } else {
-        m_iFilterLength = i;
-    }
-}
-
-int Rotary::getFilterLength() {
-    return  m_iFilterLength;
+/* Note: There's probably a bug in this function (or this class) somewhere.
+    The filter function seems to be the cause of the "drifting" bug in the Hercules stuff.
+    What happens is that filter() gets called to do some magic to a value that's returned
+    from the Hercules device, and that magic adds "momentum" to it's motion (ie. it doesn't
+    stop dead when you stop spinning the jog wheels.) The problem with this "magic" is that
+    when herculeslinux.cpp passes the filtered value off to the wheel ControlObject (or what
+    have you), the ControlObject's internal value never goes back to zero properly.
+    - Albert (March 13, 2007)
+*/
+double Rotary::filter(double v) {
+    append(v);
+    return calculate();
 }
diff --git a/src/util/rotary.h b/src/util/rotary.h
index 52c73264223..b191a74c525 100644
--- a/src/util/rotary.h
+++ b/src/util/rotary.h
@@ -2,39 +2,25 @@
 
 #include <vector>
 
+#include "util/assert.h"
+
+// Simple moving average
 class Rotary {
-  public:
-    Rotary();
+    using Buffer = std::vector<double>;
+    using index_type = Buffer::size_type;
 
-    // Start calibration measurement
-    void calibrateStart();
-    // End calibration measurement
-    double calibrateEnd();
-    // Set calibration
-    void setCalibration(double c);
-    // Get calibration
-    double getCalibration();
+  public:
+    Rotary(qsizetype filterLength)
+            : m_filterHistory(filterLength, 0.0) {
+        DEBUG_ASSERT(filterLength > 0);
+    };
     // Low pass filtered rotary event
-    double filter(double dValue);
-    // Hard set event value
-    double fillBuffer(double dValue);
-    // Collect calibration data
-    void calibrate(double dValue);
-    // Set filter length
-    void setFilterLength(int i);
-    // Get filter length
-    int getFilterLength();
+    double filter(double value);
 
-  protected:
-    // Length of filter
-    int m_iFilterLength;
-    // Update position in filter
-    int m_iFilterPos;
-    // Pointer to rotary filter buffer
-    std::vector<double> m_pFilter;
-    // Calibration value
-    double m_dCalibration;
-    // Last value
-    double m_dLastValue;
-    int m_iCalibrationCount;
+  private:
+    index_type nextIndex(index_type);
+    void append(double v);
+    double calculate() const;
+    Buffer m_filterHistory;
+    index_type m_headIndex;
 };
diff --git a/src/util/semanticversion.cpp b/src/util/semanticversion.cpp
index 3e0053f18f4..39e7bbe81b2 100644
--- a/src/util/semanticversion.cpp
+++ b/src/util/semanticversion.cpp
@@ -1,37 +1,27 @@
 #include "util/semanticversion.h"
 
 #include <QRegularExpression>
+#include <QString>
+#include <QStringView>
 
 namespace {
-
-QRegularExpression regex("(?<major>\\d+)\\.(?<minor>\\d+)\\.(?<patch>\\d+)");
+// thread local because SemanticVersion constructors below accesses it mutably.
+// making it thread_local should avoid a datarace without having to introduce locking.
+thread_local QRegularExpression regex(
+        QStringLiteral("(?<major>\\d+)\\.(?<minor>\\d+)\\.(?<patch>\\d+)"));
 
 } // anonymous namespace
 
 namespace mixxx {
 
-SemanticVersion::SemanticVersion(unsigned int majorVersion,
-        unsigned int minorVersion,
-        unsigned int patchVersion)
-        : majorVersion(majorVersion),
-          minorVersion(minorVersion),
-          patchVersion(patchVersion) {
-}
-
 SemanticVersion::SemanticVersion(const QString& versionString)
-        : majorVersion(0),
-          minorVersion(0),
-          patchVersion(0) {
+        : SemanticVersion() {
     QRegularExpressionMatch match = regex.match(versionString);
     if (match.hasMatch()) {
-        majorVersion = match.captured(QStringLiteral("major")).toUInt();
-        minorVersion = match.captured(QStringLiteral("minor")).toUInt();
-        patchVersion = match.captured(QStringLiteral("patch")).toUInt();
+        majorVersion = match.capturedView(QStringView(u"major")).toUInt();
+        minorVersion = match.capturedView(QStringView(u"minor")).toUInt();
+        patchVersion = match.capturedView(QStringView(u"patch")).toUInt();
     }
 }
 
-bool SemanticVersion::isValid() const {
-    return !(majorVersion == 0 && minorVersion == 0 && patchVersion == 0);
-}
-
 } // namespace mixxx
diff --git a/src/util/semanticversion.h b/src/util/semanticversion.h
index 9ef99cf2d9a..c8a9a9f276e 100644
--- a/src/util/semanticversion.h
+++ b/src/util/semanticversion.h
@@ -1,38 +1,60 @@
 #pragma once
 
-#include <QString>
+#include <compare>
 #include <tuple>
 
+class QString;
+
 namespace mixxx {
 
 // "major" and "minor" clash with symbols in glibc, so use more verbose variable names.
 class SemanticVersion {
   public:
-    SemanticVersion(unsigned int majorVersion,
+    constexpr SemanticVersion(unsigned int majorVersion,
             unsigned int minorVersion,
-            unsigned int patchVersion);
-    SemanticVersion(const QString& versionString);
+            unsigned int patchVersion)
+            : majorVersion(majorVersion),
+              minorVersion(minorVersion),
+              patchVersion(patchVersion) {
+    }
 
-    bool isValid() const;
+    SemanticVersion(const QString& versionString);
 
-    unsigned int majorVersion, minorVersion, patchVersion;
+    constexpr bool isValid() const {
+        return !(majorVersion == 0 && minorVersion == 0 && patchVersion == 0);
+    }
+
+    friend constexpr std::strong_ordering operator<=>(
+            const SemanticVersion&, const SemanticVersion&) noexcept;
+
+    friend constexpr bool operator==(
+            const SemanticVersion&, const SemanticVersion&) noexcept;
+
+    // Do not change the order because the synthesized comparison operators
+    // depend on it!
+    unsigned int majorVersion;
+    unsigned int minorVersion;
+    unsigned int patchVersion;
+
+  private:
+    // you should not be able to create an invalid version easily from the outside
+    constexpr SemanticVersion()
+            : SemanticVersion(0, 0, 0){};
+    // make tuple, which is used for the implementation of the comparison operators
+    constexpr std::tuple<unsigned int, unsigned int, unsigned int> makeTuple() const {
+        return std::tie(majorVersion, minorVersion, patchVersion);
+    }
 };
 
-inline bool operator<(const SemanticVersion& a, const SemanticVersion& b) {
-    return std::tie(a.majorVersion, a.minorVersion, a.patchVersion) <
-            std::tie(b.majorVersion, b.minorVersion, b.patchVersion);
-}
-
-inline bool operator>(const SemanticVersion& a, const SemanticVersion& b) {
-    return b < a;
-}
-
-inline bool operator<=(const SemanticVersion& a, const SemanticVersion& b) {
-    return !(a > b);
+// TODO: replace with = default (synthesized) implementations once widely
+// supported on target compilers.
+constexpr std::strong_ordering operator<=>(
+        const SemanticVersion& lhs, const SemanticVersion& rhs) noexcept {
+    return lhs.makeTuple() <=> rhs.makeTuple();
 }
 
-inline bool operator>=(const SemanticVersion& a, const SemanticVersion& b) {
-    return !(a < b);
+constexpr bool operator==(
+        const SemanticVersion& lhs, const SemanticVersion& rhs) noexcept {
+    return lhs.makeTuple() == rhs.makeTuple();
 }
-
 } // namespace mixxx
diff --git a/src/util/task.cpp b/src/util/task.cpp
index 6b4906e20a8..6a437fb27df 100644
--- a/src/util/task.cpp
+++ b/src/util/task.cpp
@@ -3,13 +3,9 @@
 #include <QtDebug>
 
 #include "moc_task.cpp"
-#include "util/compatibility/qatomic.h"
-
-TaskWatcher::TaskWatcher(QObject* pParent) : QObject(pParent) {
-}
 
 TaskWatcher::~TaskWatcher() {
-    if (atomicLoadRelaxed(m_activeTasks) > 0) {
+    if (m_activeTasks.loadRelaxed() > 0) {
         qWarning() << "TaskWatcher destroyed before all tasks were done.";
     }
 }
diff --git a/src/util/task.h b/src/util/task.h
index 4fae197e74b..908e2317e0c 100644
--- a/src/util/task.h
+++ b/src/util/task.h
@@ -5,11 +5,14 @@
 
 // Waits for a number of tasks to complete and emits allTasksDone() once all are
 // complete.
+// Deprecated: This is just a unnecessarily heavy counter. You should probably refrain
+// from using this in new code in favor of appropriate QtConcurrent primitives.
 class TaskWatcher : public QObject {
     Q_OBJECT
   public:
-    TaskWatcher(QObject* pParent=NULL);
-    virtual ~TaskWatcher();
+    TaskWatcher(QObject* pParent = nullptr)
+            : QObject(pParent){};
+    ~TaskWatcher() override;
 
     // Increment the number of active tasks by one and watch pTask for
     // doneSignal. This should be called before the task starts to prevent a
diff --git a/src/util/threadcputimer.cpp b/src/util/threadcputimer.cpp
deleted file mode 100644
index a40cb7b021a..00000000000
--- a/src/util/threadcputimer.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-#include "util/threadcputimer.h"
-
-#if defined(__APPLE__)
-#include <sys/time.h>
-#include <unistd.h>
-#include <mach/mach_time.h>
-#elif defined(__UNIX__)
-#include <time.h>
-#include <unistd.h>
-#elif defined(_WIN32)
-#include <windows.h>
-#endif
-
-
-////////////////////////////// Unix //////////////////////////////
-#if defined(Q_OS_UNIX)
-
-#if (_POSIX_THREAD_CPUTIME-0 != 0)
-static const bool threadCpuTimeChecked = true;
-static const bool threadCpuTimeAvailable = _POSIX_THREAD_CPUTIME > 0;
-#else
-static int threadCpuTimeChecked = false;
-static int threadCpuTimeAvailable = false;
-#endif
-
-#ifdef Q_CC_GNU
-# define is_likely(x) __builtin_expect((x), 1)
-#else
-# define is_likely(x) (x)
-#endif
-#define load_acquire(x) ((volatile const int&)(x))
-#define store_release(x,v) ((volatile int&)(x) = (v))
-
-static void unixCheckClockType()
-{
-#if (_POSIX_THREAD_CPUTIME-0 == 0)
-    if (is_likely(load_acquire(threadCpuTimeChecked))) {
-        return;
-    }
-
-# if defined(_SC_THREAD_CPUTIME)
-    // detect if the system support monotonic timers
-    long x = sysconf(_SC_THREAD_CPUTIME);
-    store_release(threadCpuTimeAvailable, x >= 200112L);
-# endif
-
-    store_release(threadCpuTimeChecked, true);
-#endif
-}
-
-static inline void do_gettime(qint64 *sec, qint64 *frac)
-{
-#if (_POSIX_MONOTONIC_CLOCK-0 >= 0)
-    unixCheckClockType();
-    if (is_likely(threadCpuTimeAvailable)) {
-        timespec ts;
-        clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
-        *sec = ts.tv_sec;
-        *frac = ts.tv_nsec;
-        return;
-    }
-#else
-    Q_UNUSED(threadCpuTimeChecked);
-    Q_UNUSED(threadCpuTimeAvailable);
-    Q_UNUSED(unixCheckClockType);
-#endif
-    *sec = 0;
-    *frac = 0;
-}
-
-void ThreadCpuTimer::start()
-{
-    do_gettime(&t1, &t2);
-}
-
-mixxx::Duration ThreadCpuTimer::elapsed() const
-{
-    qint64 sec, frac;
-    do_gettime(&sec, &frac);
-    sec = sec - t1;
-    frac = frac - t2;
-
-    return mixxx::Duration::fromNanos(sec * Q_INT64_C(1000000000) + frac);
-}
-
-mixxx::Duration ThreadCpuTimer::restart()
-{
-    qint64 sec, frac;
-    sec = t1;
-    frac = t2;
-    do_gettime(&t1, &t2);
-    sec = t1 - sec;
-    frac = t2 - frac;
-    return mixxx::Duration::fromNanos(sec * Q_INT64_C(1000000000) + frac);
-}
-
-////////////////////////////// Default //////////////////////////////
-#else
-
-// default implementation (no hi-perf timer) does nothing
-void ThreadCpuTimer::start()
-{
-}
-
-mixxx::Duration ThreadCpuTimer::elapsed() const
-{
-    return mixxx::Duration::fromNanos(0);
-}
-
-mixxx::Duration ThreadCpuTimer::restart()
-{
-    return mixxx::Duration::fromNanos(0);
-}
-
-#endif
diff --git a/src/util/threadcputimer.h b/src/util/threadcputimer.h
deleted file mode 100644
index bb8c3922f3e..00000000000
--- a/src/util/threadcputimer.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#pragma once
-
-#include "util/duration.h"
-
-class ThreadCpuTimer {
-  public:
-    void start();
-    mixxx::Duration elapsed() const;
-    mixxx::Duration restart();
-  private:
-#if defined(Q_OS_UNIX)
-    qint64 t1;
-    qint64 t2;
-#endif
-};
diff --git a/src/util/time.h b/src/util/time.h
index 87dad6d7b85..8c13566b701 100644
--- a/src/util/time.h
+++ b/src/util/time.h
@@ -4,13 +4,11 @@
 
 #include "util/duration.h"
 #include "util/performancetimer.h"
-#include "util/threadcputimer.h"
 
 namespace mixxx {
 
 class Time {
     using LLTIMER = PerformanceTimer;
-    // using LLTIMER = ThreadCpuTimer;
 
   public:
     using rep = LLTIMER::ClockT::rep;
diff --git a/src/util/trace.h b/src/util/trace.h
index 4c9615bb867..09b07eb42a1 100644
--- a/src/util/trace.h
+++ b/src/util/trace.h
@@ -11,8 +11,7 @@
 
 class Trace {
   public:
-    Trace(const char* tag, const char* arg=NULL,
-          bool writeToStdout=false, bool time=true)
+    Trace(const char* tag, const char* arg = nullptr, bool writeToStdout = false, bool time = true)
             : m_writeToStdout(writeToStdout),
               m_time(time) {
         if (writeToStdout || CmdlineArgs::Instance().getDeveloper()) {
@@ -20,15 +19,6 @@ class Trace {
         }
     }
 
-    Trace(const char* tag, int arg,
-          bool writeToStdout=false, bool time=true)
-            : m_writeToStdout(writeToStdout),
-              m_time(time) {
-        if (writeToStdout || CmdlineArgs::Instance().getDeveloper()) {
-            initialize(tag, QString::number(arg));
-        }
-    }
-
     Trace(const char* tag, const QString& arg,
           bool writeToStdout=false, bool time=true)
             : m_writeToStdout(writeToStdout),
@@ -38,7 +28,7 @@ class Trace {
         }
     }
 
-    virtual ~Trace() {
+    ~Trace() {
         // Proxy for whether initialize was called.
         if (m_tag.isEmpty()) {
             return;
@@ -86,16 +76,7 @@ class Trace {
     }
 
     QString m_tag;
-    const bool m_writeToStdout, m_time;
     PerformanceTimer m_timer;
-
-};
-
-class DebugTrace : public Trace {
-  public:
-    DebugTrace(const char* tag, bool time=true)
-            : Trace(tag, "", CmdlineArgs::Instance().getDeveloper(), time) {
-    }
-    virtual ~DebugTrace() {
-    }
+    bool m_writeToStdout;
+    bool m_time;
 };
diff --git a/src/util/types.h b/src/util/types.h
index c026e38fdb1..d4a6194f2e3 100644
--- a/src/util/types.h
+++ b/src/util/types.h
@@ -1,10 +1,9 @@
 #pragma once
 
+#include <algorithm>
 #include <climits>
 #include <cstddef>
 
-#include "util/math.h"
-
 // Signed integer type for POT array indices, sizes and pointer
 // arithmetic. Its size (32-/64-bit) depends on the CPU architecture.
 // This should be used for all CSAMLE operations since it is fast and
@@ -25,28 +24,29 @@ constexpr SAMPLE SAMPLE_MAXIMUM = SHRT_MAX;
 // amplitude of 1.0. No min/max constants here to
 // emphasize the symmetric value range of CSAMPLE
 // data!
-typedef float CSAMPLE;
+using CSAMPLE = float;
 constexpr CSAMPLE CSAMPLE_ZERO = 0.0f;
 constexpr CSAMPLE CSAMPLE_ONE = 1.0f;
 constexpr CSAMPLE CSAMPLE_PEAK = CSAMPLE_ONE;
+static_assert(sizeof(CSAMPLE) == 4); // 32 bits == 4 bytes
 
 // Limits the range of a CSAMPLE value to [-CSAMPLE_PEAK, CSAMPLE_PEAK].
-inline
-CSAMPLE CSAMPLE_clamp(CSAMPLE in) {
-    return math_clamp(in, -CSAMPLE_PEAK, CSAMPLE_PEAK);
+constexpr CSAMPLE CSAMPLE_clamp(CSAMPLE in) {
+    static_assert(-CSAMPLE_PEAK <= CSAMPLE_PEAK);
+    return std::clamp(in, -CSAMPLE_PEAK, CSAMPLE_PEAK);
 }
 
 // Gain values for weighted calculations of CSAMPLE
 // data in the range [0.0, 1.0]. Same data type as
 // CSAMPLE to avoid type conversions in calculations.
-typedef CSAMPLE CSAMPLE_GAIN;
+using CSAMPLE_GAIN = CSAMPLE;
 constexpr float CSAMPLE_GAIN_ZERO = CSAMPLE_ZERO;
 constexpr float CSAMPLE_GAIN_ONE = CSAMPLE_ONE;
 constexpr float CSAMPLE_GAIN_MIN = CSAMPLE_GAIN_ZERO;
 constexpr float CSAMPLE_GAIN_MAX = CSAMPLE_GAIN_ONE;
 
 // Limits the range of a CSAMPLE_GAIN value to [CSAMPLE_GAIN_MIN, CSAMPLE_GAIN_MAX].
-inline
-CSAMPLE_GAIN CSAMPLE_GAIN_clamp(CSAMPLE_GAIN in) {
-    return math_clamp(in, CSAMPLE_GAIN_MIN, CSAMPLE_GAIN_MAX);
+constexpr CSAMPLE_GAIN CSAMPLE_GAIN_clamp(CSAMPLE_GAIN in) {
+    static_assert(CSAMPLE_GAIN_MIN <= CSAMPLE_GAIN_MAX);
+    return std::clamp(in, CSAMPLE_GAIN_MIN, CSAMPLE_GAIN_MAX);
 }
diff --git a/src/util/valuetransformer.cpp b/src/util/valuetransformer.cpp
index 60c60fe08b0..eeff1ca0cb9 100644
--- a/src/util/valuetransformer.cpp
+++ b/src/util/valuetransformer.cpp
@@ -1,14 +1,94 @@
 #include "util/valuetransformer.h"
 
-ValueTransformer::ValueTransformer() {
-}
+#include <QDomElement>
+#include <QDomNode>
+#include <QDomNodeList>
+#include <memory>
+
+#include "skin/legacy/skincontext.h"
+
+class TransformNode {
+  public:
+    TransformNode() {
+    }
+    virtual ~TransformNode() {
+    }
 
-void ValueTransformer::addTransformer(TransformNode* pTransformer) {
-    m_transformers.append(pTransformer);
+    virtual double transform(double argument) const = 0;
+    virtual double transformInverse(double argument) const = 0;
+};
+
+namespace {
+
+class TransformAdd : public TransformNode {
+  public:
+    TransformAdd(double addend)
+            : m_addend(addend) {
+    }
+
+    double transform(double argument) const override {
+        return argument + m_addend;
+    }
+
+    double transformInverse(double argument) const override {
+        return argument - m_addend;
+    }
+
+  private:
+    double m_addend;
+};
+
+class TransformInvert : public TransformNode {
+  public:
+    double transform(double argument) const override {
+        return -argument;
+    }
+
+    double transformInverse(double argument) const override {
+        return -argument;
+    }
+};
+
+class TransformNot : public TransformNode {
+  public:
+    double transform(double argument) const override {
+        return !static_cast<bool>(argument);
+    }
+
+    double transformInverse(double argument) const override {
+        return !static_cast<bool>(argument);
+    }
+};
+
+class TransformIsEqual : public TransformNode {
+  public:
+    TransformIsEqual(double compareValue)
+            : m_compareValue(compareValue) {
+    }
+
+    double transform(double argument) const override {
+        return argument == m_compareValue;
+    }
+
+    double transformInverse(double argument) const override {
+        if (argument > 0.0) {
+            return m_compareValue;
+        }
+        return 0.0;
+    }
+
+  private:
+    double m_compareValue;
+};
+
+} // namespace
+
+void ValueTransformer::addTransformer(std::unique_ptr<TransformNode> pTransformer) {
+    m_transformers.push_back(std::move(pTransformer));
 }
 
 double ValueTransformer::transform(double argument) const {
-    foreach (const TransformNode* pNode, m_transformers) {
+    for (const auto& pNode : m_transformers) {
         argument = pNode->transform(argument);
     }
     return argument;
@@ -16,20 +96,29 @@ double ValueTransformer::transform(double argument) const {
 
 double ValueTransformer::transformInverse(double argument) const {
     for (int i = m_transformers.size() - 1; i >= 0; --i) {
-        const TransformNode* pNode = m_transformers[i];
-        argument = pNode->transformInverse(argument);
+        argument = m_transformers[i]->transformInverse(argument);
     }
     return argument;
 }
 
 // static
-ValueTransformer* ValueTransformer::parseFromXml(const QDomElement& transformElement,
-        const SkinContext& context) {
+std::unique_ptr<ValueTransformer> ValueTransformer::parseFromXml(
+        const QDomElement& transformElement, const SkinContext& context) {
     if (transformElement.isNull() || !transformElement.hasChildNodes()) {
         return nullptr;
     }
 
-    ValueTransformer* pTransformer = new ValueTransformer();
+    auto pTransformer = std::unique_ptr<ValueTransformer>(new ValueTransformer());
+
+    auto maybeAddFromElement = [&]<typename T>(auto element) {
+        QString valueStr = context.nodeToString(element);
+        bool ok = false;
+        double value = valueStr.toDouble(&ok);
+        if (ok) {
+            pTransformer->addTransformer(std::make_unique<T>(value));
+        }
+    };
+
     QDomNodeList children = transformElement.childNodes();
     for (int i = 0; i < children.count(); ++i) {
         QDomNode node = children.at(i);
@@ -38,32 +127,21 @@ ValueTransformer* ValueTransformer::parseFromXml(const QDomElement& transformEle
         }
 
         QDomElement element = node.toElement();
-        if (element.nodeName() == "Invert") {
-            pTransformer->addTransformer(new TransformInvert());
-        } else if (element.nodeName() == "Add") {
-            QString value = context.nodeToString(element);
-            bool ok = false;
-            double addend = value.toDouble(&ok);
-            if (ok) {
-                pTransformer->addTransformer(new TransformAdd(addend));
-            }
-        } else if (element.nodeName() == "Not") {
-            pTransformer->addTransformer(new TransformNot());
-        } else if (element.nodeName() == "IsEqual") {
-            QString value = context.nodeToString(element);
-            bool ok = false;
-            double compareValue = value.toDouble(&ok);
-            if (ok) {
-                pTransformer->addTransformer(new TransformIsEqual(compareValue));
-            }
+        QString name = element.nodeName();
+        if (name == "Invert") {
+            pTransformer->addTransformer(std::make_unique<TransformInvert>());
+        } else if (name == "Add") {
+            maybeAddFromElement.operator()<TransformAdd>(element);
+        } else if (name == "Not") {
+            pTransformer->addTransformer(std::make_unique<TransformNot>());
+        } else if (name == "IsEqual") {
+            maybeAddFromElement.operator()<TransformIsEqual>(element);
         }
     }
 
     return pTransformer;
 }
 
-ValueTransformer::~ValueTransformer() {
-    foreach (TransformNode* node, m_transformers) {
-        delete node;
-    }
-}
+ValueTransformer::ValueTransformer() = default;
+
+ValueTransformer::~ValueTransformer() = default;
diff --git a/src/util/valuetransformer.h b/src/util/valuetransformer.h
index e3069ff2e91..5f824ce3b27 100644
--- a/src/util/valuetransformer.h
+++ b/src/util/valuetransformer.h
@@ -1,95 +1,25 @@
 #pragma once
 
-#include <QList>
-#include <QDomElement>
+#include <memory>
+#include <vector>
 
-#include "skin/legacy/skincontext.h"
-
-class TransformNode {
-  public:
-    TransformNode() {}
-    virtual ~TransformNode() {}
-
-    virtual double transform(double argument) const = 0;
-    virtual double transformInverse(double argument) const = 0;
-};
-
-class TransformAdd : public TransformNode {
-  public:
-    TransformAdd(double addend) : m_addend(addend) {}
-
-    double transform(double argument) const {
-        return argument + m_addend;
-    }
-
-    double transformInverse(double argument) const {
-        return argument - m_addend;
-    }
-
-  private:
-    double m_addend;
-};
-
-class TransformInvert : public TransformNode {
-  public:
-    TransformInvert() {}
-
-    double transform(double argument) const {
-        return -argument;
-    }
-
-    double transformInverse(double argument) const {
-        return -argument;
-    }
-};
-
-class TransformNot : public TransformNode {
-  public:
-    TransformNot() {}
-
-    double transform(double argument) const {
-        return !static_cast<bool>(argument);
-    }
-
-    double transformInverse(double argument) const {
-        return !static_cast<bool>(argument);
-    }
-};
-
-class TransformIsEqual : public TransformNode {
-  public:
-    TransformIsEqual(double compareValue) :
-        m_compareValue(compareValue) {
-    }
-
-    double transform(double argument) const {
-        return argument == m_compareValue;
-    }
-
-    double transformInverse(double argument) const {
-        if (argument > 0.0) {
-            return m_compareValue;
-        }
-        return 0.0;
-    }
-
-  private:
-    double m_compareValue;
-};
+class SkinContext;
+class TransformNode;
+class QDomElement;
 
 class ValueTransformer {
   public:
     ~ValueTransformer();
+
     double transform(double argument) const;
     double transformInverse(double argument) const;
 
-    static ValueTransformer* parseFromXml(const QDomElement& transformElement,
+    static std::unique_ptr<ValueTransformer> parseFromXml(const QDomElement& transformElement,
             const SkinContext& context);
 
   private:
-    ValueTransformer();
-
-    void addTransformer(TransformNode* pTransformer);
+    ValueTransformer(); // only accessible from parseFromXml, not deleted
+    void addTransformer(std::unique_ptr<TransformNode> pTransformer);
 
-    QList<TransformNode*> m_transformers;
+    std::vector<std::unique_ptr<TransformNode>> m_transformers;
 };
diff --git a/src/util/xml.cpp b/src/util/xml.cpp
index ccfee0fb986..264d5218d2c 100644
--- a/src/util/xml.cpp
+++ b/src/util/xml.cpp
@@ -1,7 +1,12 @@
+#include "util/xml.h"
+
+#include <QDomDocument>
+#include <QDomElement>
+#include <QDomNode>
 #include <QFile>
+#include <QString>
 #include <QtDebug>
 
-#include "util/xml.h"
 #include "errordialoghandler.h"
 
 int XmlParse::selectNodeInt(const QDomNode& nodeHeader,
diff --git a/src/util/xml.h b/src/util/xml.h
index 5bbb4196680..3218c6c9de6 100644
--- a/src/util/xml.h
+++ b/src/util/xml.h
@@ -1,60 +1,61 @@
 #pragma once
 
-#include <QDomNode>
-#include <QDomElement>
-#include <QDomDocument>
-
-class XmlParse {
-  public:
-    // Searches for and returns a node named sNode in the children of
-    // nodeHeader. Returns a null QDomNode if one is not found.
-    static QDomNode selectNode(const QDomNode& nodeHeader,
-                               const QString& sNode);
-
-    // Searches for and returns an element named sNode in the children of
-    // nodeHeader. Returns a null QDomElement if one is not found.
-    static QDomElement selectElement(const QDomNode& nodeHeader,
-                                     const QString& sNode);
-
-    // Searches for an element named sNode in the children of nodeHeader and
-    // parses the text value of its children as an integer. Returns 0 if sNode
-    // is not found in nodeHeader's children.
-    static int selectNodeInt(const QDomNode& nodeHeader,
-                             const QString& sNode, bool* ok = 0);
-
-    // Searches for an element named sNode in the children of nodeHeader and
-    // parses the text value of its children as a float. Returns 0.0f if sNode
-    // is not found in nodeHeader's children.
-    static float selectNodeFloat(const QDomNode& nodeHeader,
-                                 const QString& sNode, bool* ok = 0);
-
-    // Searches for an element named sNode in the children of nodeHeader and
-    // parses the text value of its children as a double. Returns 0.0 if sNode
-    // is not found in nodeHeader's children.
-    static double selectNodeDouble(const QDomNode& nodeHeader,
-                                   const QString& sNode, bool* ok = 0);
-
-    // Searches for an element named sNode in the children of nodeHeader and
-    // parses the text value of its children as a bool. Returns false if sNode
-    // is not found in nodeHeader's children.
-    static bool selectNodeBool(const QDomNode& nodeHeader,
-            const QString& sNode);
-
-    // Searches for an element named sNode in the children of nodeHeader and
-    // returns the text value of its children. Returns the empty string if sNode
-    // is not found in nodeHeader's children.
-    static QString selectNodeQString(const QDomNode& nodeHeader,
-                                     const QString& sNode);
-
-    // Open an XML file.
-    static QDomElement openXMLFile(const QString& path, const QString& name);
-
-    // Add an element named elementName to the provided header element with a
-    // child text node with the value textValue. Returns the created element.
-    static QDomElement addElement(QDomDocument& document, QDomElement& header,
-                                  const QString& elementName, const QString& textValue);
-
-  private:
-    XmlParse() {}
-    ~XmlParse() {}
-};
+class QDomNode;
+class QString;
+class QDomElement;
+class QDomDocument;
+
+namespace XmlParse {
+// Searches for and returns a node named sNode in the children of
+// nodeHeader. Returns a null QDomNode if one is not found.
+QDomNode selectNode(const QDomNode& nodeHeader,
+        const QString& sNode);
+
+// Searches for and returns an element named sNode in the children of
+// nodeHeader. Returns a null QDomElement if one is not found.
+QDomElement selectElement(const QDomNode& nodeHeader,
+        const QString& sNode);
+
+// Searches for an element named sNode in the children of nodeHeader and
+// parses the text value of its children as an integer. Returns 0 if sNode
+// is not found in nodeHeader's children.
+int selectNodeInt(const QDomNode& nodeHeader,
+        const QString& sNode,
+        bool* ok = nullptr);
+
+// Searches for an element named sNode in the children of nodeHeader and
+// parses the text value of its children as a float. Returns 0.0f if sNode
+// is not found in nodeHeader's children.
+float selectNodeFloat(const QDomNode& nodeHeader,
+        const QString& sNode,
+        bool* ok = nullptr);
+
+// Searches for an element named sNode in the children of nodeHeader and
+// parses the text value of its children as a double. Returns 0.0 if sNode
+// is not found in nodeHeader's children.
+double selectNodeDouble(const QDomNode& nodeHeader,
+        const QString& sNode,
+        bool* ok = nullptr);
+
+// Searches for an element named sNode in the children of nodeHeader and
+// parses the text value of its children as a bool. Returns false if sNode
+// is not found in nodeHeader's children.
+bool selectNodeBool(const QDomNode& nodeHeader,
+        const QString& sNode);
+
+// Searches for an element named sNode in the children of nodeHeader and
+// returns the text value of its children. Returns the empty string if sNode
+// is not found in nodeHeader's children.
+QString selectNodeQString(const QDomNode& nodeHeader,
+        const QString& sNode);
+
+// Open an XML file.
+QDomElement openXMLFile(const QString& path, const QString& name);
+
+// Add an element named elementName to the provided header element with a
+// child text node with the value textValue. Returns the created element.
+QDomElement addElement(QDomDocument& document,
+        QDomElement& header,
+        const QString& elementName,
+        const QString& textValue);
+} // namespace XmlParse
diff --git a/src/waveform/renderers/waveformwidgetrenderer.h b/src/waveform/renderers/waveformwidgetrenderer.h
index 47cd21b67a6..c99833a39ee 100644
--- a/src/waveform/renderers/waveformwidgetrenderer.h
+++ b/src/waveform/renderers/waveformwidgetrenderer.h
@@ -181,7 +181,7 @@ class WaveformWidgetRenderer {
 
     void setPlayMarkerPosition(double newPos) {
         VERIFY_OR_DEBUG_ASSERT(newPos >= 0.0 && newPos <= 1.0) {
-            newPos = math_clamp(newPos, 0.0, 1.0);
+            newPos = std::clamp(newPos, 0.0, 1.0);
         }
         m_playMarkerPosition = newPos;
     }
diff --git a/src/widget/whotcuebutton.cpp b/src/widget/whotcuebutton.cpp
index 0e91f1812ad..b37a7874364 100644
--- a/src/widget/whotcuebutton.cpp
+++ b/src/widget/whotcuebutton.cpp
@@ -4,6 +4,7 @@
 
 #include "mixer/playerinfo.h"
 #include "moc_whotcuebutton.cpp"
+#include "skin/legacy/skincontext.h"
 #include "track/track.h"
 #include "widget/controlwidgetconnection.h"
 
diff --git a/src/widget/wpushbutton.cpp b/src/widget/wpushbutton.cpp
index 5cc3c188203..07f81be7d5d 100644
--- a/src/widget/wpushbutton.cpp
+++ b/src/widget/wpushbutton.cpp
@@ -11,6 +11,7 @@
 #include "control/controlobject.h"
 #include "control/controlpushbutton.h"
 #include "moc_wpushbutton.cpp"
+#include "skin/legacy/skincontext.h"
 #include "util/debug.h"
 #include "widget/controlwidgetconnection.h"
 #include "widget/wpixmapstore.h"
diff --git a/src/widget/wpushbutton.h b/src/widget/wpushbutton.h
index 1e4ff3ddf09..94fbad7e6b4 100644
--- a/src/widget/wpushbutton.h
+++ b/src/widget/wpushbutton.h
@@ -5,7 +5,7 @@
 #include <QVector>
 #include <memory>
 
-#include "control/controlpushbutton.h"
+#include "control/controlbuttonmode.h"
 #include "util/fpclassify.h"
 #include "util/performancetimer.h"
 #include "widget/wpixmapstore.h"
diff --git a/src/widget/wslidercomposed.cpp b/src/widget/wslidercomposed.cpp
index 52c6c0c60d8..e6eef93cf87 100644
--- a/src/widget/wslidercomposed.cpp
+++ b/src/widget/wslidercomposed.cpp
@@ -6,6 +6,7 @@
 #include <QtDebug>
 
 #include "moc_wslidercomposed.cpp"
+#include "skin/legacy/skincontext.h"
 #include "util/debug.h"
 #include "widget/controlwidgetconnection.h"
 #include "widget/wpixmapstore.h"