I am trying to return a CArray from a function and trying to call the function from another class
short ListMaker::RetArray(CString szName, CArray<CString, CString&> &szarr_Names) {
szarr_Names.Add(szName);
return 0;
}
int main() {
//..
CArray<CString, CString&> myArray;
ListMaker LM;
short nCode = LM.RetArray(L"Name", myArray);
//..
}
I am getting following errors:
Error 1 error C2664: 'RetArray' : cannot convert parameter 2 from 'CArray<TYPE,ARG_TYPE>' to 'CArray<TYPE,ARG_TYPE>'
Error 2 error C2511: 'short RetArray(CString,CArray<TYPE,ARG_TYPE> &)' : overloaded member function not found in 'ListMaker'
Please tell me the correct way to define and access the return value of the CArray.
Erm, frist of all if RetArray is a member of ListMaker class and you call it from main(), you cannot call it like this: short nCode = RetArray(L"Name", myArray);
If RetArray is a static member, use short nCode = ListMaker::RetArray(L"Name", myArray);. It it's non-static, use instance, short nCode = listMakerInstance.RetArray(L"Name", myArray);.
Check your header file for RetArray declaration in ListMaker class. It might differ from the implementation in your cpp file, hence you get the C2511 error.
You cannot store a reference in an array type, and CArray is to be absolutely avoided at all costs as it uses memcpy to resize and not copy construction, breaking your code the instant you need something with a useful constructor.
I think the problem is in CString&, try using CArray<CString, LPCTSTR> instead.
Related
When I am calling SetParams function from the below function, it is throwing an error "cannot convert argument 1 from 'std::wstring' to 'wchar_t *'"
Can anyone please help me on this?
int main()
{
IVerify* pReader = new BCReader();
std::wstring oemPathKey;
pReader->SetParams(oemPathKey, L"read");
delete pReader;
return 0;
}
void BCReader::SetParams(wchar_t* wszParams, wchar_t* wszParamType)
{
m_wszParamType = wszParamType;
m_wszParams = wszParams;
}
The member variables are declared like as shown below:
class IVerify
{
private:
wchar_t* m_wszParams;
wchar_t* m_wszParamType;
};
There are two parts of the right answer:
1. You need to use pReader->SetParams(oemPathKey.c_str(), L"read");
2. Your approach is not safe, you trying to keep pointer to string in the class members.
But if the original string will go out of scope then you will receive Access Vioalation, if you are lucky :). So in SetParams you need to copy source string to the class members uisng for example wscpy (I recommend something like wscpy_s), also you need correctly handle allocation/deallocation for string copy.
I'm not going to get into too much of the details on the Excel side of things, I essentially took code from this example:
C++ app automates Excel (CppAutomateExcel)
solution1.cpp
So I've tried this code in MSVC and it compiles:
class foo { public: virtual void bar(){} };
int main()
{
void (foo::*p)() = &foo::bar;
}
But similar code to capture the address of the move function in Excel does not work:
int main()
{
Excel::_ApplicationPtr spXlApp;
HRESULT hr = spXlApp.CreateInstance(__uuidof(Excel::Application));
Excel::WorkbooksPtr spXlBooks = spXlApp->Workbooks;
Excel::_WorkbookPtr spXlBook = spXlBooks->Add();
Excel::_WorksheetPtr spXlSheet = spXlBook->ActiveSheet;
HRESULT(Excel::_Worksheet::*pMove)(...) = &spXlSheet->Excel::_Worksheet::Move;
<... irrelevant code ...>
return 0;
}
This has the following compiler error:
error C2276: '&': illegal operation on bound member function expression
If I remove the &, it says I should add it back:
error C3867: 'Excel::_Worksheet::Move': non-standard syntax; use '&' to create a pointer to member
Any help on what to do here would be greatly appreciated.
You say in your question "but similar code..." and then you show code in which you do not do the same thing. Try using the same syntax for setting pMove as you used for setting p in your smaller example. Try something like &Excel::_Worksheet::Move; (without the "spXlSheet->").
If you can specify the specific instance of the object for which to call the function pointer at the time that you set the function pointer as you have there, I'm not aware of such a capability. After dropping spXlSheet-> from where you set the variable, use it instead where you want to call the function pointer.
You need to declare the method pointer like this instead:
// or whatever parameter type Move() actually uses...
void (Excel::_Worksheet::*pMove)(tagVARIANT, tagVARIANT) = &Excel::_Worksheet::Move;
Then, to actually call pMove(), you would have to do something like this:
Excel::_WorksheetPtr spXlSheet = ...;
(spXlSheet.Get()->*pMove)(...);
I have
template < typename threadFuncParamT >
class ThreadWrapper
{
public:
static int ThreadRoutineFunction(void* pParam);
int ExecuteThread();
ThreadWrapper(ThreadPool<threadFuncParamT> *pPool);
};
template<typename threadFuncParamT>
int ThreadWrapper<threadFuncParamT>::ThreadRoutineFunction(void* pParam)
{
ThreadWrapper<threadFuncParamT> *pWrapper = reinterpret_cast<ThreadWrapper<threadFuncParamT>*>(pParam);
if(pWrapper != NULL)
{
return pWrapper-ExecuteThread(); // Error here.
}
return 0;
}
template < typename threadFuncParamT >
ThreadWrapper<threadFuncParamT>::ThreadWrapper(ThreadPool<threadFuncParamT> *pPool)
{
ThreadWrapper<threadFuncParamT>::m_pThreadPool = pPool;
m_tbbThread = new tbb::tbb_thread(&(ThreadWrapper<threadFuncParamT>::ThreadRoutineFunction), this);
if (m_tbbThread->native_handle() == 0)
{
delete m_tbbThread;
m_tbbThread = NULL;
// TODO: throw execption here or raise assert.
}
}
I am getting error as below
Error 1 error C2352: 'ThreadWrapper::ExecuteThread' : illegal call of non-static member function
I am compiling on VS2010.
Can any one help me here how to get clear the error.
Thanks!
The problem is that your error line
return pWrapper-ExecuteThread(); // Error here.
misses an >; it should read
return pWrapper->ExecuteThread(); // Error here.
You're getting such a strange compile error since it's trying to perform a subtraction; the pointer pWrapper is treated as an integer, and the value returned by calling ExecuteThread() (which yields an int) is subtracted from that. However, ExecuteThread() is neither a global function nor a static member function - hence the compiler complains.
You're missing the > on the call. You want return pWrapper->ExecuteThread();
You're missing the ">"
It's
pWrapper->ExecuteThread()
not
pWrapper-ExecuteThread()
You can't call static member function with that syntax. Try doing the following instead:
static_cast<ThreadWrapper*>(pParam)->ExecuteThread();
Maybe superfluous, but an explanation: functions that are entry points for threads cannot be instance methods, they must be file-scope function or static methods. The common idiom is to pass a void pointer to a static/global thread startup routine, cast that pointer to the proper class type and use it to call the actual instance method that will be executed in anothre thread.
I have the following and having difficulty resolving the error please help.
i have the following class as template definition somewhere.
template<class ConcreteHandlerType>
class SomeAcceptor: public ACE_Acceptor<ConcreteHandlerType, ACE_SOCK_Acceptor>
In some other file, i initialize this class in the constructor
class initialize {
typedef SomeAcceptor<BaseClassSomeHandler> baseAcceptor_t;
typedef SomeAcceptor<DerivedClassSomeHandler> derivedAcceptor_t;
boost::shared_ptr<baseAcceptor_t;> mAcceptor;
boost::shared_ptr<derivedAcceptor_t;> mDerivedAcceptor;
bool HandleAcceptNotification(BaseClassSomeHandler& someHandler);
initialize() : mAcceptor(0), mDerivedAcceptor(new DerivedAcceptor_t) {
mAcceptor->SetAcceptNotificationDelegate(fastdelegate::MakeDelegate(this, &initialize::HandleAcceptNotification));
}
}
Error i get is
error: no matching function for call to `boost::shared_ptr<SomeAcceptor<BaseClassSomeHandler> >::shared_ptr(int)'common/lib/boost_1_39_0/boost/smart_ptr/shared_ptr.hpp:160: note: candidates are: boost::shared_ptr<SomeAcceptor<BaseClassSomeHandler> >::shared_ptr(const boost::shared_ptr<SomeAcceptor<BaseClassSomeHandler> >&)
common/lib/boost_1_39_0/boost/smart_ptr/shared_ptr.hpp:173: notboost::shared_ptr<T>::shared_ptr() [with T = SomeAcceptor<BaseClassSomeHandler>]
I also tried overloading the function with
bool HandleAcceptNotification(DerivedClassSomeHandler& someHandler);
but because mAcceptor is of type SomeAcceptor BaseClassSomeHandler, i get this error, but to fix this.
I guess i need to cast it somehow, but how to do it?
i tried doing like below inside the constructor and it didn't work
initialize() : mAcceptor(0), mDerivedAcceptor(new DerivedAcceptor_t) {
mAcceptor = mDerivedAcceptor; // Error here
mAcceptor->SetAcceptNotificationDelegate(fastdelegate::MakeDelegate(this, &initialize::HandleAcceptNotification));
}
From your code, it looks like you want mAcceptor to be assigned NULL (0), if that is the case you don't need to initialize it at all, as the default constructor will take care of that. But, since you call a function on that (NULL) pointer immediately, its not immediately clear exactly what you want to do.
If you want mAcceptor and mDerivedAcceptor to point to the same (shared) object and assuming DerivedClassSomeHandler is derived from BaseClassSomeHandler, this is a situation where you should use boost::shared_static_cast, as described here.
There's also some good information in this apparently related question.
The error is due to the mAcceptor(0) in
initialize() : mAcceptor(0), mDerivedAcceptor(new DerivedAcceptor_t) {
mAcceptor->SetAcceptNotificationDelegate(fastdelegate::MakeDelegate(this, &initialize::HandleAcceptNotification));
}
The smart_ptr default constructor assigns the wrapped ptr to NULL, so leave out mAcceptor(0) from the initialization list.
boost::shared_ptr<SomeAcceptor<BaseClassSomeHandler> >::shared_ptr(int)
It's yelling at you that there's no constructor that accepts an int.
Just use: mAcceptor()
My code was working fine until I reloaded the program a few hours later. Now I get these this error:
error C3867: 'player::getxPos': function call missing argument list; use '&player::getxPos' to create a pointer to member
error C3867: 'player::getyPos': function call missing argument list; use '&player::getyPos' to create a pointer to member
This is the code in question:
if (P->shoot())
{
shotVector.push_back(shot());
eS = shotVector.size();
shotVector[eS-1].initShot(
P->getxPos, // C3867
P->getyPos // C3867
);
}
I'm trying to call two functions from a class called player and these two functions look like this:
int player::getxPos(){
return xPos;
};
int player::getyPos(){
return yPos;
};
What's being done is that I'm trying to ask for the players position and then use that to decide where to shoot from.
shotVector[eS-1].initShot(P->getxPos, P->getyPos); - you are trying to call the getxPos() and getyPos() members without ().
Use getxPos() and getyPos().
You forgot the parenthesis, which tell the compiler that you want a method call:
P->getxPos
vs
P->getxPos()
If you instead used &P->getxPos, that would give you a pointer to the member function itself.
shotVector[eS-1].initShot(P->getxPos(), P->getyPos());