IceProxy : passing a method pointer as a variable

flatmax

I get the following compiler error for the listed code :
error: address of overloaded function with no contextual type information

I have an ICE method :

module NAMESPACE {
  class MyClass {
    void myFunc(MyClass* proxy)
    sequence<string> getStringVector(const string &key);
  }
}

I am trying to pass a pointer to this method as a variable using the proxy :

void MyClassI<BASECLASS>::myFunc(const NAMESPACE::MyClassPrx& proxy, const Ice::Current&) { 
  myOtherFunc((vector<string> (*)(const string&))
                     (&IceProxy::NAMESPACE::MyClass::getStringVector))l
}

Any help appreciated.

thanks
Matt

bernard

Hi Matt,

Welcome to our forums. slice2cpp generates two overloaded functions for each Slice operation (e.g. getStringVector), one with a context parameter (as last parameter), and one without.

What is the declaration of myOtherFunc?

Best regards,
Bernard

flatmax

I see what you are saying, there are 4 methods which map to the getStringVector ... is this perhaps why the compiler is getting confused ?

To answer your question :

myOtherFunc is actually a method of a different class. It is called like so :
e->myOtherFunc
where e is a pointer member variable.

The compiler actually reports the problem when I instantiate the templates :

template class MyClassI<TemplateClass1>;
template class MyClassI<TemplateClass2>;

line #1 : instantiated from here
line #1b error: address of overloaded function with no contextual type information

line #2 : instantiated from here
line #2b error: address of overloaded function with no contextual type information

where line #1 matches the template and #1b matches the myOtherFunc call.

flatmax

I have managed to get around this problem temporarily (although am currently dubious that it will work as I am not able to get proxy->getStringVector) by using the following :
NAMESPACE::stringVectorT (IceProxy::NAMESPACE::MyClass::*f)(const string &)=(&IceProxy::NAMESPACE::MyClass::getStringVector);

Then I use 'f' in my method :
myOtherFunc(f);

I now have the problem where the compiler wants the original method to be called with an Ice::Current variable :
void MyClassI<BASECLASS>::myFunc(const NAMESPACE::MyClassPrx& proxy, const Ice::Current&);

Where do I get Ice::Current from ?
The compiler will not let me call myFunc(proxy);
It is asking me to provide 'Ice::Current'

thanks
Matt

marc

Ice::Current is passed as the last parameter to every operation on the server side. Have a look at the documentation for details.

flatmax

Sure - I have given up on using proxy method passing for execution in other methods.

xdm

Hi,

Based in Ice Hello demo something like this should work.

// C++ code

void (IceProxy::Demo::Hello::*ptSayHello)(int) = 0;

void doit(HelloPrx instane, void (IceProxy::Demo::Hello::*ptSayHello)(int))
{
    (instane.get()->*ptSayHello)(0);
}

// ....

int
HelloClient::run(int argc, char* argv[])
{
    //...
    HelloPrx twoway = HelloPrx::checkedCast(
communicator()->propertyToProxy("Hello.Proxy")->ice_twoway()->ice_timeout(-1)->ice_secure(false));

    ptSayHello = &IceProxy::Demo::Hello::sayHello;
    doit(twoway, ptSayHello);

flatmax

Thanks for the demo.
I think my problem was that the instance was templated and the compiler couldn't map to the method to call ... because of template confusion ... I tried many methods including double casts to override the problem... but to no avail !

Matt