Polymorphic Boost Function

[Peter_APIIT]

Dear all, Is it possible for boost function to store a polymorphic function like this.

typedef boost::function<encryptionStrategy* (encryptionStrategyFactory* ) > factoryFn;

std::vector<factoryFn> factoryCont;

 factoryCont.push_back(&encryptionStrategyFactory::createEncryptor);
factoryCont.push_back(&AESEncryptionFactory::createEncryptor);
factoryCont.push_back(&RSAEncryptionFactory::createEncryptor);

The AESEncryptionFactory and RSAEncryptionFactory are inherited from base class encryptionStrategyFactory but i encounter like conversion problem.

Is the polymorphic behaviour supports in Boost Function ?

Please help.

Thanks.

[Codeplug]

Virtual member-function pointers are called polymorphically - evn through a boost::function object.

You have to have an object instance to call a member function pointer:

#include <boost/function.hpp>
#include <iostream>
#include <vector>
using namespace std;

struct A
{
    virtual void foo() {cout << "A::foo" << endl;}
};//A

struct B : public A
{
    virtual void foo() {cout << "B::foo" << endl;}
};//B

struct C : public A
{
    virtual void foo() {cout << "C::foo" << endl;}
};//C

int main()
{
    A a;
    B b;
    C c;

    typedef boost::function<void (A*)> Fn;
    vector<Fn> vFn;
    vFn.push_back(&A::foo);

    vFn[0](&a);
    vFn[0](&b);
    vFn[0](&c);
  
    return 0;
}//main

So you only need to push_back a &encryptionStrategyFactory::createEncryptor. Then use the factory instance when invoking the pushed-back member-function pointer.

gg

[Peter_APIIT]

Thanks codeplug.