Re: [Boost-users] ptr_map trouble

Pau Garcia i Quiles skrev:

Hello,

I'm having trouble when adding elements to a ptr_map. If I use a ptr_vector instead, it works (code for ptr_map and ptr_vector follows).

* With ptr_map: ===============

#include <iostream> #include <string> #include #include #include

class Base { };

class X : public Base { public: std::string text() { std::cout<< std::string("hello world!") << std::endl; return std::string("hello world!"); } };

class Y : public Base { public: int value() { return 5; } };

class Z : public Base { public: bool isEnabled() { return true; } };

// [...] // There will be hundreds of classes like X, Y and Z, only quite more complex

class ProxyBase { public: virtual boost::any field() = 0; };

template<class T> class Proxy : public ProxyBase { typedef T result_type;

public: Proxy(T& inst, boost::function f) : inst_(inst), f_(f) { ; };

boost::any field() { return boost::any( f_(inst_) ); }

T& inst_; boost::function f_;

};

int main() {

boost::ptr_map m;

X x; Proxy<X>* px = new Proxy<X>(x, boost::mem_fn(&X::text)); std::cout << "Calling a proxy object Proxy<X> outputs: " << boost::any_caststd::string( px->field() ) << std::endl;

// m.insert(std::string("test"), px ); // FIXME Why does this 'insert' fail?

Please see the FAQ: http://www.boost.org/doc/libs/1_35_0/libs/ptr_container/doc/faq.html#why-doe... -Thorsten