fix: warning with C++20 and gcc compiler

Author: knst

src/qt/appearancewidget.cpp

@@ -46,11 +46,11 @@ AppearanceWidget::AppearanceWidget(QWidget* parent) :
     connect(ui->fontWeightNormalSlider, &QSlider::valueChanged, [this](auto nValue) { updateFontWeightNormal(nValue); });
     connect(ui->fontWeightBoldSlider, &QSlider::valueChanged, [this](auto nValue) { updateFontWeightBold(nValue); });
 
-    connect(ui->theme, &QComboBox::currentTextChanged, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontFamily, &QComboBox::currentTextChanged, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontScaleSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontWeightNormalSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
-    connect(ui->fontWeightBoldSlider, &QSlider::sliderReleased, [=]() { Q_EMIT appearanceChanged(); });
+    connect(ui->theme, &QComboBox::currentTextChanged, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontFamily, &QComboBox::currentTextChanged, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontScaleSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontWeightNormalSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
+    connect(ui->fontWeightBoldSlider, &QSlider::sliderReleased, [this]() { Q_EMIT appearanceChanged(); });
 }
 
 AppearanceWidget::~AppearanceWidget()

src/qt/bitcoingui.cpp

@@ -240,7 +240,7 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const NetworkStyle* networkStyle,
     bool fDebugCustomStyleSheets = gArgs.GetBoolArg("-debug-ui", false) && GUIUtil::isStyleSheetDirectoryCustom();
     if (fDebugCustomStyleSheets) {
         timerCustomCss = new QTimer(this);
-        QObject::connect(timerCustomCss, &QTimer::timeout, [=]() {
+        QObject::connect(timerCustomCss, &QTimer::timeout, [this]() {
             if (!m_node.shutdownRequested()) {
                 GUIUtil::loadStyleSheet();
             }
@@ -291,7 +291,7 @@ void BitcoinGUI::startSpinner()
     };
 
     timerSpinner = new QTimer(this);
-    QObject::connect(timerSpinner, &QTimer::timeout, [=]() {
+    QObject::connect(timerSpinner, &QTimer::timeout, [this, getNextFrame]() {
         if (timerSpinner == nullptr) {
             return;
         }
@@ -319,7 +319,7 @@ void BitcoinGUI::startConnectingAnimation()
     }
 
     timerConnecting = new QTimer(this);
-    QObject::connect(timerConnecting, &QTimer::timeout, [=]() {
+    QObject::connect(timerConnecting, &QTimer::timeout, [this]() {
 
         if (timerConnecting == nullptr) {
             return;
@@ -1353,7 +1353,7 @@ void BitcoinGUI::openOptionsDialogWithTab(OptionsDialog::Tab tab)
     connect(dlg, &OptionsDialog::quitOnReset, this, &BitcoinGUI::quitRequested);
     dlg->setCurrentTab(tab);
     dlg->setModel(clientModel->getOptionsModel());
-    connect(dlg, &OptionsDialog::appearanceChanged, [=]() {
+    connect(dlg, &OptionsDialog::appearanceChanged, [this]() {
         updateWidth();
     });
     GUIUtil::ShowModalDialogAndDeleteOnClose(dlg);

src/qt/optionsdialog.cpp

@@ -194,7 +194,7 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
     appearanceLayout->addWidget(appearance);
     ui->widgetAppearance->setLayout(appearanceLayout);
 
-    connect(appearance, &AppearanceWidget::appearanceChanged, [=](){
+    connect(appearance, &AppearanceWidget::appearanceChanged, [this](){
         updateWidth();
         Q_EMIT appearanceChanged();
     });
@@ -277,13 +277,13 @@ void OptionsDialog::setModel(OptionsModel *_model)
     connect(ui->lang, qOverload<>(&QValueComboBox::valueChanged), [this]{ showRestartWarning(); });
     connect(ui->thirdPartyTxUrls, &QLineEdit::textChanged, [this]{ showRestartWarning(); });
 
-    connect(ui->coinJoinEnabled, &QCheckBox::clicked, [=](bool fChecked) {
+    connect(ui->coinJoinEnabled, &QCheckBox::clicked, [this](bool fChecked) {
 #ifdef ENABLE_WALLET
         model->node().coinJoinOptions().setEnabled(fChecked);
 #endif
         updateCoinJoinVisibility();
-        if (_model != nullptr) {
-            _model->emitCoinJoinEnabledChanged();
+        if (this->model != nullptr) {
+            this->model->emitCoinJoinEnabledChanged();
         }
         updateWidth();
     });
@@ -293,7 +293,7 @@ void OptionsDialog::setModel(OptionsModel *_model)
     // Store the current CoinJoin enabled state to recover it if it gets changed but the dialog gets not accepted but declined.
 #ifdef ENABLE_WALLET
     fCoinJoinEnabledPrev = model->node().coinJoinOptions().isEnabled();
-    connect(this, &OptionsDialog::rejected, [=]() {
+    connect(this, &OptionsDialog::rejected, [this]() {
         if (fCoinJoinEnabledPrev != model->node().coinJoinOptions().isEnabled()) {
             ui->coinJoinEnabled->click();
         }

src/qt/overviewpage.cpp

@@ -328,7 +328,7 @@ void OverviewPage::setWalletModel(WalletModel *model)
         connect(model->getOptionsModel(), &OptionsModel::coinJoinRoundsChanged, this, &OverviewPage::updateCoinJoinProgress);
         connect(model->getOptionsModel(), &OptionsModel::coinJoinAmountChanged, this, &OverviewPage::updateCoinJoinProgress);
         connect(model->getOptionsModel(), &OptionsModel::AdvancedCJUIChanged, this, &OverviewPage::updateAdvancedCJUI);
-        connect(model->getOptionsModel(), &OptionsModel::coinJoinEnabledChanged, [=]() {
+        connect(model->getOptionsModel(), &OptionsModel::coinJoinEnabledChanged, [this]() {
             coinJoinStatus(true);
         });