different types of objects in the same vector array?
I am using an array in a simple logic simulator program and I want to switch to using a vector to learn it but the reference I am using "OOP in C++ by Lafore" doesn't have a lot about vectors and objects so I am kinda of lost .
Here is the previous code :
gate* G[1000];
G[0] = new ANDgate() ;
G[1] = new ORgate;
//gate is a class inherited by ANDgate and ORgate classes
class gate
{
.....
......
void Run()
{ //A virtual function
}
};
class ANDgate :public gate
{.....
.......
void Run()
{
//AND version of Run
}
};
class ORgate :public gate
{.....
.......
void Run()
{
//OR version of Run
}
};
//Running the simulator using overloading concept
for(...;...;..)
{
G[i]->Run() ; //will run perfectly the right Run for the right Gate type
}
Now what I want to do is
vector(gate*) G;
ANDgate a
G.push_back(a); //Error
ORgate o
G.push_back(o); //Error
for(...;...;...)
{
G[i]->Run(); //Will this work if I corrected the error ??
}
so can a vector array hold different types of objects(ANDgate , ORgate) but they inherit the type of the开发者_Python百科 vector array (gate) ????
You're half-way there:
std::vector<gate*> G;
G.push_back(new ANDgate);
G.push_back(new ORgate);
for(unsigned i=0;i<G.size();++i)
{
G[i]->Run();
}
Of course, this way you need to take care to ensure that your objects are deleted. I'd use a vector of a smart pointer type such as boost::shared_ptr
to manage that for you. You could just store the address of local objects (e.g. G.push_back(&a)
), but then you need to ensure that the pointers are not referenced after the local objects have been destroyed.
Yes, that will work - as long as you make run() a virtual function in gate and use the address of operator(&) on a and o as you put them in the vector.
Be careful about object lifetime issues though. If a and/or o go out of scope then your vector will contain pointers to invalid objects.
Also, the base class "Gate" should have a virtual destructor else there would be issues while cleaning up the vector and it's contents.
You are using
vector(gate*) G;
change to
vector<gate*> G;
and you should do this
G.push_back(new ANDgate());
or if you use boost use shared_ptrs as vector does quite a lot of copying and naked pointers in a vector can be fatal.
精彩评论