my code is like this
in A.cpp
#include "rclcpp_lifecycle/rclcpp_lifecycle.hpp"
#include "B.hpp"
#include "D.hpp"
class A : public B, public rclcpp_lifecycle::LifecycleNode
{
A();
virtual ~A();
on_configure(...)
{
func_A()
}
func_A()
{
D::func_D(B::shared_from_this());
}
};
in D.cpp
class D
{
D();
~D();
static func_D(shared_ptr<B>){}
};
in main.cpp
#include "A.hpp"
int main()
{
std::shared_ptr<A> node = make_shared<A>("a");
rclcpp::spin(node);
}
then, in func_A, throw bad_weak_ptr
I think that rclcpp::spin keeps the shared_ptr of A, but it doesn't
what am i missing?
Related
I regularly expose c++ classes to python using boost.python & MSVC 12 (dynamic linking). Recently I have been trying to include documentation using the "docstring_options" class. The documentation examples work fine:
http://www.boost.org/doc/libs/1_54_0/libs/python/doc/v2/docstring_options.html
However, when I include a class and expose it I get linker errors:
error LNK2019: unresolved external symbol "void __cdecl boost::throw_exception(class std::exception const &)" (?throw_exception#boost##YAXABVexception#std###Z) referenced in function "public: __thiscall boost::detail::shared_count::shared_count(void *,struct boost::python::converter::shared_ptr_deleter)"
I'm sure there is probably something simple I'm missing but I can't figure it out.
Many thanks in advance!
sample code spliced from the boost examples that gives this error for me.
#include <string>
#include <boost/python/module.hpp>
#include <boost/python/def.hpp>
#include <boost/python/args.hpp>
#include <boost/python/docstring_options.hpp>
#include <boost/python.hpp>
struct World
{
void set(std::string msg) { this->msg = msg; }
std::string greet() { return msg; }
std::string msg;
};
int foo1(int i) { return i; }
int foo2(long l) { return static_cast<int>(l); }
int bar1(int i) { return i; }
int bar2(long l) { return static_cast<int>(l); }
namespace {
void wrap_foos()
{
using namespace boost::python;
def("foo1", foo1, arg("i"), "foo1 doc");
def("foo2", foo2, arg("l"), "foo2 doc");
}
void wrap_bars()
{
using namespace boost::python;
bool show_user_defined = true;
bool show_signatures = false;
docstring_options doc_options(show_user_defined, show_signatures);
def("bar1", bar1, arg("i"), "bar1 doc");
def("bar2", bar2, arg("l"), "bar2 doc");
class_<World>("World")
.def("greet", &World::greet)
.def("set", &World::set)
;
}
}
BOOST_PYTHON_MODULE(boost_py_doc_demo)
{
boost::python::docstring_options doc_options(false);
wrap_foos();
wrap_bars();
}
I compiled the latest version of boost (1.63) and now the problem has gone. I guess my old libraries were incomplete in some way.
I have a project where I am expanding existing native C++ compatible code functionality for a customer-facing library by integrating a driver from a managed DLL, which seems like the opposite direction for most marshaling questions. Since there can be multiple devices using this one driver, each device needs to be its own object, with its own callback methods. This integration will take the form of a native wrapper DLL that exposes the native class interface to the customer-facing library, which will pass an instance of a member method callback function pointer to the DLL. I need to pass a native method member instance (non-static) as a delegate to the managed wrapper class. The managed wrapper class uses GetDelegateForFunctionPointer, which works to marshal static native pointers to a delegate, but I can't find any information if it works with instances. GetDelegateForFunctionPointer also takes a System::IntPtr argument for the function pointer, but I'm also not sure if System::IntPtr works for instances, and when compiling in VC++2008 I'm being presented an error C3867 for attempting this.
Managed wrapper header:
//somemanagedclass.hpp
#pragma once
using namespace System;
using namespace ExternalManagedLibrary;
namespace SomeNameSpace
{
public ref class SomeManagedClass
{
public:
SomeManagedClass();
~SomeManagedClass();
delegate void CallbackHandler(const wchar_t*, int);
CallbackHandler^ CallbackEvent;
void RegisterCallback(IntPtr callbackEvent);
private:
ExternalManagedClass^ externalManagedClass;
void OnCallback(Object^ sender, ValueEventArgs<String^>^ e);
};
}
Managed wrapper source:
//somemanagedclass.cpp
#include "somemanagedclass.hpp"
#include <vcclr.h>
using namespace System;
using namespace Runtime::InteropServices;
namespace SomeNameSpace
{
SomeManagedClass::SomeManagedClass()
{
externalManagedClass = gcnew ExternalManagedClass();
externalManagedClass->CallbackEvent += gcnew EventHandler<ValueEventArgs<String^>^>(this, &SomeManagedClass::OnCallback);
}
SomeManagedClass::~SomeManagedClass()
{
externalManagedClass->CallbackEvent -= gcnew EventHandler<ValueEventArgs<String^>^>(this, &SomeManagedClass::OnCallback);
}
void SomeManagedClass::OnCallback(Object^ sender, ValueEventArgs<String^>^ e)
{
String^ some_string = String::Copy(e->Value);
cli::pin_ptr<const wchar_t> pinned_string = &PtrToStringChars(some_string)[0];
const wchar_t* p = pinned_string;
CallbackEvent(pinned_string, some_string->Length);
}
void SomeManagedClass::RegisterCallback(IntPtr callbackEvent)
{
CallbackEvent = (CallbackHandler^)(Marshal::GetDelegateForFunctionPointer(callbackEvent, CallbackHandler::typeid));
}
}
Native wrapper interface:
//somenativeinterface.hpp
#ifdef DLL_EXPORT
#define IMPORT_EXPORT __declspec(dllexport)
#else
#define IMPORT_EXPORT __declspec(dllimport)
#endif //DLL_EXPORT
typedef void (*NativeCallback)(const unsigned char*, unsigned long);
class IMPORT_EXPORT SomeNativeInterface
{
public:
//class factory
static SomeNativeInterface* Create(void);
static void Destroy(SomeNativeInterface* clInterface);
virtual void CallbackInit(NativeCallback fnNativeCallbackInit);
};
Native wrapper header:
//somenativeclass.hpp
#pragma once
#include "somenativeinterface.hpp"
#include "somemanagedclass.hpp"
#include <vcclr.h>
using namespace SomeNameSpace;
class IMPORT_EXPORT SomeNativeClass : public SomeNativeInterface
{
public:
SomeNativeClass();
~SomeNativeClass();
void CallbackInit(NativeCallback fnNativeCallbackInit); //can this take an instance?
private:
NativeCallback fnNativeCallback;
void OnNativeCallback(const wchar_t* cString, int iSize);
gcroot<SomeManagedClass^> wrapper; //warning C4251
};
Native wrapper source:
//somenativeclass.cpp
#include "somenativeclass.hpp"
#include <vcclr.h>
#include <string.h>
using namespace System;
using namespace Runtime::InteropServices;
SomeNativeInterface* SomeNativeInterface::Create()
{
return ((SomeNativeInterface*) new SomeNativeClass());
}
void SomeNativeInterface::Destroy(SomeNativeInterface* instance)
{
delete instance;
}
SomeNativeClass::SomeNativeClass()
{
wrapper = gcnew SomeManagedClass();
}
SomeNativeClass::OnNativeCallback(const wchar_t* cString, int iSize)
{
std::auto_ptr<char> pcConvertedString(new char[iSize+1]);
size_t iCharsConverted;
if (wcstombs_s(&iCharsConverted, (char*)*pcConvertedString, iSize+1, cString, iSize) == 0)
{
if (iCharsConverted > 0xFFFFFFFF)
iCharsConverted = 0xFFFFFFFF; //truncate
fnNativeCallback((const unsigned char*)*pcConvertedString, (unsigned long)(iCharsConverted));
}
}
SomeNativeClass::CallbackInit(NativeCallback fnNativeCallbackInit)
{
fnNativeCallback = fnNativeCallbackInit;
wrapper->RegisterCallback(System::IntPtr(this->OnNativeCallback)); //error C3867
}
I have,
time.h:
#pragma once
#ifndef TIME_H
#define TIME_H
class time
{
private:
int hour;
int minute;
int second;
public:
enum pmORam {am,pm};
time(void);
time(int,int,int);
void printtime(void);
time subtime(time &);
const time &operator=(const time &);
void setTime(int,int,int);
~time(void);
};
#endif
time.cpp:
#include <iostream>
#include <iomanip>
#include "stdafx.h"
#include "time.h"
using namespace std;
time::time(void)
{
hour=0;
minute=0;
second=0;
}
time::time(int hr,int min,int sec)
{
setTime(hr,min,sec);
}
void time::printtime(void)
{
enum pmORam p;
if(hour<=12 && hour>=0)
cout<<setfill('0')<<setw(2)<<hour<<":"<<setw(2)<<minute<<":"<<setw(2)<<second<<p.am<<endl;
else
if(hour>12 && hour<=23)
{
hour=hour%12;
cout<<setfill('0')<<setw(2)<<hour<<":"<<setw(2)<<minute<<":"<<setw(2)<<second<<p.pm<<endl;
}
}
const time &time::operator=(const time &t)
{
hour=t.hour;
minute=t.minute;
second=t.second;
return *this;
}
time time::subtime(time &m)
{
if(hour>m.hour)
{
if(m.second>second)
{
minute=minute-1;
second=(second+60)-m.second;
}
second=second-m.second;
if(m.minute>minute)
{
hour=hour-1;
minute=(minute+60)-m.minute;
}
minute=minute-m.minute;
hour=hour-m.hour;
}
if(second>m.second)
{
m. minute=m.minute-1;
m.second=(m.second+60)-second;
}
m.second=m.second-second;
if(minute>m.minute)
{
m.hour=m.hour-1;
m.minute=(m.minute+60)-minute;
}
m.hour=hour-m.hour;
return *this;
}
void time::setTime(int hr,int min,int sec)
{
hour=(hr>=0 && hr<=23)? hr: 0;
minute=(min>=0 && min<60)? min:0;
second=(sec>=0 && sec<60)? sec:0;
}
time::~time(void)
{
}
But in time.cpp i get to this Errors:
IntelliSense: declaration is incompatible with "time time::subtime(time &)"
IntelliSense: declaration is incompatible with "const time &time::operator=(const time &)"
'time::time(const time &)' : cannot convert parameter 1 from 'time *const ' to 'const time &'
'int time::subtime(time &)' : overloaded function differs only by return type from 'time time::subtime(time &)'
'int &time::operator =(const time &)' : overloaded function differs only by return type from 'const time &time::operator =(const time &)'
function "time" is not a type name
What is Problem?
Edit: New code to fix naming conflict
time.cpp:
#include <iostream>
#include <iomanip>
#include "stdafx.h"
#include "time.h"
using namespace std;
timea::timea(void)
{
hour=0;
minute=0;
second=0;
}
timea::timea(int hr,int min,int sec)
{
setTime(hr,min,sec);
}
void timea::printtime(void)
{
enum timea::pmORam p;
if(hour<=12 && hour>=0)
cout<<setfill('0')<<setw(2)<<hour<<":"<<setw(2)<<minute<<":"<<setw(2)<<second<<p.am<<endl;
else
if(hour>12 && hour<=23)
{
hour=hour%12;
cout<<setfill('0')<<setw(2)<<hour<<":"<<setw(2)<<minute<<":"<<setw(2)<<second<<p.pm<<endl;
}
}
const timea &timea::operator=(const timea &t)
{
hour=t.hour;
minute=t.minute;
second=t.second;
return *this;
}
timea timea::subtime(timea &m)
{
if(hour>m.hour)
{
if(m.second>second)
{
minute=minute-1;
second=(second+60)-m.second;
}
second=second-m.second;
if(m.minute>minute)
{
hour=hour-1;
minute=(minute+60)-m.minute;
}
minute=minute-m.minute;
hour=hour-m.hour;
}
if(second>m.second)
{
m. minute=m.minute-1;
m.second=(m.second+60)-second;
}
m.second=m.second-second;
if(minute>m.minute)
{
m.hour=m.hour-1;
m.minute=(m.minute+60)-minute;
}
m.hour=hour-m.hour;
return *this;
}
void timea::setTime(int hr,int min,int sec)
{
hour=(hr>=0 && hr<=23)? hr: 0;
minute=(min>=0 && min<60)? min:0;
second=(sec>=0 && sec<60)? sec:0;
}
timea::~timea(void)
{
}
There's a header file in the Standard library named time.h. It's likely that either
You're including the system header file when you wanted your own, or
System header files are pulling in yours when they wanted the standard one
or both. Find a different name for your header.
In addition, the identifier time in the global namespace is used by a function in the Standard library (hence the error function "time" is not a type name). So put yours inside a namespace or change the class name.
Specifically, your errors are caused by ignoring this rule, found in 17.6.4.3.3:
Each name from the Standard C library declared with external linkage is reserved to the implementation for use as a name with extern "C" linkage, both in namespace std and in the global namespace.
Each function signature from the Standard C library declared with external linkage is reserved to the implementation for use as a function signature with both extern "C" and extern "C++" linkage, or as a name of namespace scope in the global namespace.
I'm using Qt 5.1.0 and QtQuick 2.0.
I've just learned how to exchange data and method between qml and C++. In detail, I want to expose a (nested) structure, so I created classes which contains the required properties and methods.
It works, but I cannot share the very same instance between C++ and qml. Changing something from C++ side leads to no changes in qml side.
A short example:
main.cpp
#include <QtGui/QGuiApplication>
#include <QtQml>
#include "qtquick2applicationviewer.h"
#include "myclass.h"
int main(int argc, char *argv[]) {
QGuiApplication app(argc, argv);
qmlRegisterType<MyClass>("MyLibrary", 1, 0, "MyClass");
MyClass *myclass = new MyClass();
Category *cat = new Category();
cat->setName("foo");
myclass->append(cat);
qDebug() << myclass->categoriesCount(); // returns 1 OK!
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/main.qml"));
viewer.show();
return app.exec();
}
myclass.h
#include <QObject>
class Category : public QObject {
Q_OBJECT
Q_PROPERTY(QString name READ name WRITE setName)
public:
Category() {}
QString name() const { return m_name; }
void setName(QString name) { m_name = name; }
private:
QString m_name;
};
class MyClass : public QObject {
Q_OBJECT
Q_PROPERTY(QList<QObject*> categories READ categories NOTIFY categoriesChanged)
Q_PROPERTY(int categoriesCount READ categoriesCount)
public:
QList<QObject*> categories() const { return m_categories; }
void clear() { m_categories.clear(); }
void append(Category *category) { m_categories.append(category); }
int categoriesCount() const { return m_categories.count(); }
private:
QList<QObject*> m_categories;
signals:
void categoriesChanged();
};
main.qml
import QtQuick 2.0
import MyLibrary 1.0
Item {
id: root
width: 360
height: 360
Text {
id: foo
text: myclass.categoriesCount // writes 0 -> should be 1
}
MyClass {
id: myclass
}
}
I'm afraid the qml engine accesses to a different instance of the class myclass created in the main file.
I am developing one BB 10 app in which I have coded first page (with NavigationPane) in C++. Now I want to push another qml page in NavigationPane on button click. I have tried following code with no luck
QmlDocument *qml = QmlDocument::create("asset:///main.qml").parent(this);
if (!qml->hasErrors()) {
Page *page = qml->createRootObject<Page>();
mRoot->push(page);
}
How can I achieve this?
Here is how can you push page using NavigationPane in C++:
Source file:
#include <bb/cascades/Application>
#include <bb/cascades/Button>
#include <bb/cascades/Label>
#include <bb/cascades/ActionItem>
#include <bb/cascades/Container>
#include <bb/cascades/DockLayout>
#include <bb/cascades/TitleBar>
#include <bb/cascades/NavigationPaneProperties>
#include "Sandoxproject.hpp"
using namespace bb::cascades;
SandboxApp::SandboxApp(bb::cascades::Application *app)
: QObject(app)
{
_navPane.reset(NavigationPane::create());
Page* firstPage = createFirstPage();
_navPane ->push(firstPage);
_secondPage.reset(createSecondPage());
app->setScene(_navPane.data());
}
bb::cascades::Page* SandboxApp::createFirstPage() {
Page* page = new Page();
Container* content = new Container();
TitleBar* titleBar = TitleBar::create().visibility(ChromeVisibility::Visible).title("First Page");
page->setTitleBar(titleBar);
content->setLayout(DockLayout::create());
Button* button = Button::create().text("Go to another page").horizontal(HorizontalAlignment::Center).vertical(VerticalAlignment::Center);
connect(button, SIGNAL(clicked()), this, SLOT(pushPage()));
content->add(button);
page->setContent(content);
return page;
}
bb::cascades::Page* SandboxApp::createSecondPage() {
Page* page = new Page();
TitleBar* titleBar = TitleBar::create().visibility(ChromeVisibility::Visible).title("Second Page");
page->setTitleBar(titleBar);
ActionItem* backAction = ActionItem::create();
connect(backAction, SIGNAL(triggered()), _navPane.data(), SLOT(pop()));
page->setPaneProperties(NavigationPaneProperties::create().backButton(backAction));
Container* content = new Container();
content->setLayout(DockLayout::create());
content->add(Label::create().text("This is the second page").horizontal(HorizontalAlignment::Center).vertical(VerticalAlignment::Center));
page->setContent(content);
return page;
}
void SandboxApp::pushPage() {
qDebug("pushing another page...");
_navPane->push(_secondPage.data());
}
Header file:
#ifndef Sandoxproject_HPP_
#define Sandoxproject_HPP_
#include <bb/cascades/NavigationPane>
#include <bb/cascades/Page>
#include <QObject>
namespace bb { namespace cascades { class Application; }}
class SandboxApp : public QObject
{
Q_OBJECT
public:
SandboxApp(bb::cascades::Application *app);
virtual ~SandboxApp() {}
private slots:
void pushPage();
private:
bb::cascades::Page* createFirstPage();
bb::cascades::Page* createSecondPage();
QScopedPointer<bb::cascades::NavigationPane> _navPane;
QScopedPointer<bb::cascades::Page> _secondPage;
Q_DISABLE_COPY(SandboxApp);
};
#endif /* Sandoxproject_HPP_ */