尝试创建一个对象的std::shared_ptr，该对象将std::shared_ptr作为参数导致"无匹配的构造函数，用于初始化'对象'"编译错误。
我的代码看起来如下：
// Sidebar Widgets
_widgets.sideBarWidgetLeft = std::make_shared<SideBarWidget>();
_widgets.sideBarWidgetLeft->hide();
_widgets.sideBarWidgetRight = std::make_shared<SideBarWidget>();
_widgets.sideBarWidgetRight->hide();
// Pointer Test
CalibrationManagementWidget* test = new CalibrationManagementWidget( _widgets.sideBarWidgetLeft, 0 );
// Sidebar Left
_widgets.calibrationManagementWidget = std::make_shared<CalibrationManagementWidget>( _widgets.sideBarWidgetLeft, 0 );
_widgets.calibrationManagementWidget->hide();
_widgets.cameraWidget = std::make_shared<CameraWidget>( 0, VISUALISATION_TYPE_NORMAL );
_widgets.cameraWidget->hide();
当"指针测试"编译时，"侧边栏左"下的线创建了命名错误。我做错了什么，或者一般不可能吗？
这是（一个）错误消息：
/usr/include/c++/5.4.0/ext/new_allocator.h:120: Error: no matching constructor for initialization of 'CalibrationManagementWidget'
{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
编辑：
根据要求，我将发布一些片段，其中还包含校准Widget的构造函数。
calibrationwidget.h
...
Q_INVOKABLE CalibrationManagementWidget(QWidget* parent = 0 , VisualisationType visuType = VISUALISATION_TYPE_TRANSLATOR);
CalibrationManagementWidget( std::shared_ptr<SideBarWidget> sideBarWidget, QWidget* parent = 0 );
virtual ~CalibrationManagementWidget();
...
calibrationwidget.cpp
...
CalibrationManagementWidget::CalibrationManagementWidget(QWidget* parent, enum VisualisationType visuType) : CommonWindowWidget( WIDGET_TYPE_3D, "", "Calibration Management", 0, Ui::UI_WINDOW_FLAG_CLOSABLE, 0, parent, visuType) {
_currentMessage = 0;
_selectedCalibrationType = CALIBRATION_TYPE_UNKNOWN;
_messageEventLoop = new QEventLoop(this);
_updateTimer = new QTimer();
setupUi();
}
CalibrationManagementWidget::CalibrationManagementWidget(std::shared_ptr<SideBarWidget> sideBarWidget, QWidget* parent) : CommonWindowWidget( WIDGET_TYPE_3D, "", "Calibration Management", 0, Ui::UI_WINDOW_FLAG_CLOSABLE, sideBarWidget, parent) {
_currentMessage = 0;
_selectedCalibrationType = CALIBRATION_TYPE_UNKNOWN;
_messageEventLoop = new QEventLoop(this);
_updateTimer = new QTimer();
setupUi();
}
CalibrationManagementWidget::~CalibrationManagementWidget() {
delete _messageEventLoop;
_messageEventLoop = 0;
delete _updateTimer;
_updateTimer = 0;
}
...
这也是来自CommonWindowWidget的摘要。
commonwindowwidget.h
...
CommonWindowWidget(WidgetType widgetType, const QString& headerTitle = "Foldable Widget", const string& pageName = "Foldable Widget", unsigned int view = 0, unsigned int uiWindowFlags = 0, std::shared_ptr<SideBarWidget> sideBarWidget = 0, QWidget* parent = 0, VisualisationType visuType = VISUALISATION_TYPE_NORMAL);
virtual ~CommonWindowWidget();
...
commonwindowwidget.cpp
...
CommonWindowWidget::CommonWindowWidget(WidgetType widgetType, const QString& headerTitle, const string& pageName, unsigned int view, unsigned int uiWindowFlags, std::shared_ptr<SideBarWidget> sideBarWidget, QWidget* parent, VisualisationType visuType) : CommonStackedWidget(widgetType, pageName, view, parent, visuType) {
_windowFlags = uiWindowFlags;
_sideBarWidget = std::move(sideBarWidget);
setupUi();
_ui.headerWidget->headerLabel()->setText( headerTitle );
connect( _ui.headerWidget, SIGNAL(headerDoubleClicked()), this, SLOT(changeFoldState()));
connect( _ui.headerWidget, SIGNAL(changeFoldStateClicked()), this, SLOT(changeFoldState()));
connect( _ui.headerWidget, SIGNAL(closeClicked()), this, SLOT(navigateToHome()));
}
CommonWindowWidget::~CommonWindowWidget() {
}
...
转发时，0导致参数推导为int，它不再可转换为指针。
只有字面的 0可以代表指针，但是在传递给make_shared后，字面变为int值0，这会导致错误，因为构造函数期望指针。
而是使用nullptr：
_widgets.calibrationManagementWidget =
std::make_shared<CalibrationManagementWidget>(
_widgets.sideBarWidgetLeft, nullptr
);
这是引入nullptr的主要原因。
说明：https：//channel9.msdn.com/shows/oving defe ddeep/stephan-t-lavavej-verything-you-very-you-ever-ever-want- to-ever-to-know-about-nullptr，大约28:00。<<<<<<<<<<<<<<<<<<