Upgrade to C++20

cmake/modules/ErrorFlags.cmake

@@ -44,6 +44,9 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
 			"-Werror" # Treat warnings as errors
 		)
 	endif()
+
+	set(SILENCE_DEPRECATION_DEFS "")
+	set(THIRD_PARTY_SILENCE_DEPRECATION_DEFS "")
 elseif(MSVC)
 	set(COMPILE_ERROR_FLAGS
 		"/W2" # Enable some warnings by default
@@ -65,8 +68,12 @@ elseif(MSVC)
 			"/WX" # Treat warnings as errors
 		)
 	endif()
+
+	set(SILENCE_DEPRECATION_DEFS "_SILENCE_CXX20_OLD_SHARED_PTR_ATOMIC_SUPPORT_DEPRECATION_WARNING")
+	set(THIRD_PARTY_SILENCE_DEPRECATION_DEFS "")
 endif()
 
 # Add the flags to the whole directory tree. We use the third-party flags for
 # targets whose SYSTEM property is true, and the normal flags otherwise.
 add_compile_options("$<IF:$<BOOL:$<TARGET_PROPERTY:SYSTEM>>,${THIRD_PARTY_COMPILE_ERROR_FLAGS},${COMPILE_ERROR_FLAGS}>")
+add_compile_definitions("$<IF:$<BOOL:$<TARGET_PROPERTY:SYSTEM>>,${THIRD_PARTY_SILENCE_DEPRECATION_DEFS},${SILENCE_DEPRECATION_DEFS}>")

plugins/CMakeLists.txt

@@ -2,8 +2,8 @@ SET(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
 SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
 SET(CMAKE_DEBUG_POSTFIX "")
 
-# Enable C++17
-SET(CMAKE_CXX_STANDARD 17)
+# Enable C++20
+SET(CMAKE_CXX_STANDARD 20)
 
 IF(LMMS_BUILD_APPLE AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
 	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")

plugins/SpectrumAnalyzer/SaControlsDialog.cpp

@@ -341,7 +341,6 @@ SaControlsDialog::SaControlsDialog(SaControls *controls, SaProcessor *processor)
 	m_waterfall = new SaWaterfallView(controls, processor, this);
 	display_splitter->addWidget(m_waterfall);
 	m_waterfall->setVisible(m_controls->m_waterfallModel.value());
-	connect(&controls->m_waterfallModel, &BoolModel::dataChanged, [=] {m_waterfall->updateVisibility();});
 }
 
 

plugins/SpectrumAnalyzer/SaWaterfallView.cpp

@@ -54,6 +54,7 @@ SaWaterfallView::SaWaterfallView(SaControls *controls, SaProcessor *processor, Q
 	setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
 	connect(getGUI()->mainWindow(), SIGNAL(periodicUpdate()), this, SLOT(periodicUpdate()));
+	connect(&controls->m_waterfallModel, &BoolModel::dataChanged, this, &SaWaterfallView::updateVisibility);
 
 	m_displayTop = 1;
 	m_displayBottom = height() -2;

plugins/Vibed/NineButtonSelector.cpp

@@ -47,7 +47,7 @@ NineButtonSelector::NineButtonSelector(std::array<QPixmap, 18> onOffIcons, int d
 		m_buttons[i]->setActiveGraphic(onOffIcons[i * 2]);
 		m_buttons[i]->setInactiveGraphic(onOffIcons[(i * 2) + 1]);
 		m_buttons[i]->setChecked(false);
-		connect(m_buttons[i].get(), &PixmapButton::clicked, this, [=](){ this->buttonClicked(i); });
+		connect(m_buttons[i].get(), &PixmapButton::clicked, this, [=, this](){ buttonClicked(i); });
 	}
 
 	m_lastBtn = m_buttons[defaultButton].get();

plugins/VstBase/RemoteVstPlugin/CMakeLists.txt

@@ -6,7 +6,7 @@ endif()
 
 project(RemoteVstPlugin 
 	LANGUAGES CXX)
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 
 include(CheckCXXPreprocessor)
 include(CheckCXXSourceCompiles)
@@ -73,7 +73,7 @@ if(MSVC)
 endif()
 
 if(IS_MINGW)
-	SET(CMAKE_REQUIRED_FLAGS "-std=c++17")
+	SET(CMAKE_REQUIRED_FLAGS "-std=c++20")
 endif()
 
 if(LMMS_BUILD_WIN32)

src/3rdparty/CMakeLists.txt

@@ -15,7 +15,7 @@ ADD_SUBDIRECTORY(weakjack)
 add_library(ringbuffer OBJECT
 	ringbuffer/src/lib/ringbuffer.cpp
 )
-target_compile_features(ringbuffer PUBLIC cxx_std_17)
+target_compile_features(ringbuffer PUBLIC cxx_std_20)
 target_include_directories(ringbuffer PUBLIC
 	ringbuffer/include
 	"${CMAKE_CURRENT_BINARY_DIR}"

src/3rdparty/hiir/CMakeLists.txt

@@ -1,3 +1,3 @@
 add_library(hiir INTERFACE)
 target_include_directories(hiir INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
-target_compile_features(hiir INTERFACE cxx_std_17)
+target_compile_features(hiir INTERFACE cxx_std_20)

src/CMakeLists.txt

@@ -9,8 +9,8 @@ SET(CMAKE_AUTOMOC ON)
 SET(CMAKE_AUTOUIC ON)
 SET(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 
-# Enable C++17
-SET(CMAKE_CXX_STANDARD 17)
+# Enable C++20
+SET(CMAKE_CXX_STANDARD 20)
 
 IF(LMMS_BUILD_APPLE AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
 	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")

src/gui/FileBrowser.cpp

@@ -635,15 +635,15 @@ void FileBrowserTreeWidget::contextMenuEvent(QContextMenuEvent * e )
 
 		contextMenu.addAction(
 			tr( "Send to active instrument-track" ),
-			[=]{ sendToActiveInstrumentTrack(file); }
+			[=, this]{ sendToActiveInstrumentTrack(file); }
 		);
 
 		contextMenu.addSeparator();
 
 		contextMenu.addAction(
 			QIcon(embed::getIconPixmap("folder")),
 			tr("Open containing folder"),
-			[=]{ openContainingFolder(file); }
+			[=, this]{ openContainingFolder(file); }
 		);
 
 		auto songEditorHeader = new QAction(tr("Song Editor"), nullptr);
@@ -676,14 +676,14 @@ QList<QAction*> FileBrowserTreeWidget::getContextActions(FileItem* file, bool so
 
 	auto toInstrument = new QAction(instrumentAction + tr(" (%2Enter)").arg(shortcutMod), nullptr);
 	connect(toInstrument, &QAction::triggered,
-		[=]{ openInNewInstrumentTrack(file, songEditor); });
+		[=, this]{ openInNewInstrumentTrack(file, songEditor); });
 	result.append(toInstrument);
 
 	if (songEditor && fileIsSample)
 	{
 		auto toSampleTrack = new QAction(tr("Send to new sample track (Shift + Enter)"), nullptr);
 		connect(toSampleTrack, &QAction::triggered,
-			[=]{ openInNewSampleTrack(file); });
+			[=, this]{ openInNewSampleTrack(file); });
 		result.append(toSampleTrack);
 	}
 

src/gui/MicrotunerConfig.cpp

@@ -94,7 +94,7 @@ MicrotunerConfig::MicrotunerConfig() :
 	auto scaleCombo = new ComboBox();
 	scaleCombo->setModel(&m_scaleComboModel);
 	microtunerLayout->addWidget(scaleCombo, 1, 0, 1, 2);
-	connect(&m_scaleComboModel, &ComboBoxModel::dataChanged, [=] {updateScaleForm();});
+	connect(&m_scaleComboModel, &ComboBoxModel::dataChanged, this, &MicrotunerConfig::updateScaleForm);
 
 	m_scaleNameEdit = new QLineEdit("12-TET");
 	m_scaleNameEdit->setToolTip(tr("Scale description. Cannot start with \"!\" and cannot contain a newline character."));
@@ -106,8 +106,8 @@ MicrotunerConfig::MicrotunerConfig() :
 	saveScaleButton->setToolTip(tr("Save scale definition to a file."));
 	microtunerLayout->addWidget(loadScaleButton, 3, 0, 1, 1);
 	microtunerLayout->addWidget(saveScaleButton, 3, 1, 1, 1);
-	connect(loadScaleButton, &QPushButton::clicked, [=] {loadScaleFromFile();});
-	connect(saveScaleButton, &QPushButton::clicked, [=] {saveScaleToFile();});
+	connect(loadScaleButton, &QPushButton::clicked, this, &MicrotunerConfig::loadScaleFromFile);
+	connect(saveScaleButton, &QPushButton::clicked, this, &MicrotunerConfig::saveScaleToFile);
 
 	m_scaleTextEdit = new QPlainTextEdit();
 	m_scaleTextEdit->setPlainText("100.0\n200.0\n300.0\n400.0\n500.0\n600.0\n700.0\n800.0\n900.0\n1000.0\n1100.0\n1200.0");
@@ -117,7 +117,7 @@ MicrotunerConfig::MicrotunerConfig() :
 	auto applyScaleButton = new QPushButton(tr("Apply scale changes"));
 	applyScaleButton->setToolTip(tr("Verify and apply changes made to the selected scale. To use the scale, select it in the settings of a supported instrument."));
 	microtunerLayout->addWidget(applyScaleButton, 6, 0, 1, 2);
-	connect(applyScaleButton, &QPushButton::clicked, [=] {applyScale();});
+	connect(applyScaleButton, &QPushButton::clicked, this, &MicrotunerConfig::applyScale);
 
 	// ----------------------------------
 	// Mapping sub-column
@@ -132,7 +132,7 @@ MicrotunerConfig::MicrotunerConfig() :
 	auto keymapCombo = new ComboBox();
 	keymapCombo->setModel(&m_keymapComboModel);
 	microtunerLayout->addWidget(keymapCombo, 1, 2, 1, 2);
-	connect(&m_keymapComboModel, &ComboBoxModel::dataChanged, [=] {updateKeymapForm();});
+	connect(&m_keymapComboModel, &ComboBoxModel::dataChanged, this, &MicrotunerConfig::updateKeymapForm);
 
 	m_keymapNameEdit = new QLineEdit("default");
 	m_keymapNameEdit->setToolTip(tr("Keymap description. Cannot start with \"!\" and cannot contain a newline character."));
@@ -144,8 +144,8 @@ MicrotunerConfig::MicrotunerConfig() :
 	saveKeymapButton->setToolTip(tr("Save key mapping definition to a file."));
 	microtunerLayout->addWidget(loadKeymapButton, 3, 2, 1, 1);
 	microtunerLayout->addWidget(saveKeymapButton, 3, 3, 1, 1);
-	connect(loadKeymapButton, &QPushButton::clicked, [=] {loadKeymapFromFile();});
-	connect(saveKeymapButton, &QPushButton::clicked, [=] {saveKeymapToFile();});
+	connect(loadKeymapButton, &QPushButton::clicked, this, &MicrotunerConfig::loadKeymapFromFile);
+	connect(saveKeymapButton, &QPushButton::clicked, this, &MicrotunerConfig::saveKeymapToFile);
 
 	m_keymapTextEdit = new QPlainTextEdit();
 	m_keymapTextEdit->setPlainText("0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11");
@@ -189,7 +189,7 @@ MicrotunerConfig::MicrotunerConfig() :
 	auto applyKeymapButton = new QPushButton(tr("Apply keymap changes"));
 	applyKeymapButton->setToolTip(tr("Verify and apply changes made to the selected key mapping. To use the mapping, select it in the settings of a supported instrument."));
 	microtunerLayout->addWidget(applyKeymapButton, 6, 2, 1, 2);
-	connect(applyKeymapButton, &QPushButton::clicked, [=] {applyKeymap();});
+	connect(applyKeymapButton, &QPushButton::clicked, this, &MicrotunerConfig::applyKeymap);
 
 	updateScaleForm();
 	updateKeymapForm();
@@ -325,7 +325,7 @@ void MicrotunerConfig::updateKeymapForm()
  */
 bool MicrotunerConfig::validateScaleForm()
 {
-	auto fail = [=](QString message) {QMessageBox::critical(this, tr("Scale parsing error"), message);};
+	auto fail = [this](const QString& message){ QMessageBox::critical(this, tr("Scale parsing error"), message); };
 
 	// check name
 	QString name = m_scaleNameEdit->text();
@@ -373,7 +373,7 @@ bool MicrotunerConfig::validateScaleForm()
  */
 bool MicrotunerConfig::validateKeymapForm()
 {
-	auto fail = [=](QString message) {QMessageBox::critical(this, tr("Keymap parsing error"), message);};
+	auto fail = [this](const QString& message){ QMessageBox::critical(this, tr("Keymap parsing error"), message); };
 
 	// check name
 	QString name = m_keymapNameEdit->text();

src/gui/PluginBrowser.cpp

@@ -297,7 +297,7 @@ void PluginDescWidget::contextMenuEvent(QContextMenuEvent* e)
 	QMenu contextMenu(this);
 	contextMenu.addAction(
 		tr("Send to new instrument track"),
-		[=]{ openInNewInstrumentTrack(m_pluginKey.desc->name); }
+		[=, this]{ openInNewInstrumentTrack(m_pluginKey.desc->name); }
 	);
 	contextMenu.exec(e->globalPos());
 }

src/gui/SideBarWidget.cpp

@@ -50,7 +50,7 @@ SideBarWidget::SideBarWidget( const QString & _title, const QPixmap & _icon,
 	m_closeBtn->resize(m_buttonSize);
 	m_closeBtn->setToolTip(tr("Close"));
 	connect(m_closeBtn, &QPushButton::clicked,
-		[=]() { this->closeButtonClicked(); });
+		[this]() { this->closeButtonClicked(); });
 }
 
 

src/gui/editors/PianoRoll.cpp

@@ -3098,7 +3098,7 @@ void PianoRoll::paintEvent(QPaintEvent * pe )
 			// allow quantization grid up to 1/32 for normal notes
 			else if (q < 6) { q = 6; }
 		}
-		auto xCoordOfTick = [=](int tick) {
+		auto xCoordOfTick = [this](int tick) {
 			return m_whiteKeyWidth + (
 				(tick - m_currentPosition) * m_ppb / TimePos::ticksPerBar()
 			);

tests/CMakeLists.txt

@@ -28,5 +28,5 @@ foreach(LMMS_TEST_SRC IN LISTS LMMS_TESTS)
 		${QT_QTTEST_LIBRARY}
 	)
 
-	target_compile_features(${LMMS_TEST_NAME} PRIVATE cxx_std_17)
+	target_compile_features(${LMMS_TEST_NAME} PRIVATE cxx_std_20)
 endforeach()