Thread: Templates and Inheritance

Hi,
I'm trying to do something like the following...
I would like fill a vector with objects that are of different type variations of the same template base class.
The code below of course does not work because the vector needs a template arg. How do you get around this? A wrapper class? If so, how?
Thanks!

Code:

template <class T>
class MyClassBase {
public:
	MyClassBase() {
	}
	
	T myValue;
};

class MyClassFloat : public MyClassBase<float> {
	MyClassFloat(float myInput) {
		myValue = myInput;
	}
};

class MyClassInt : public MyClassBase<int> {
	MyClassInt(int myInput) {
		myValue = myInput;
	}
};

int main (int argc, const char * argv[])
{
    vector<MyClassBase> myVec;
    myVec.push_back(MyClassFloat(1.0));
    myVec.push_back(MyClassInt(1));
    return 0;
}

Hey, thanks, but that code doesn't work for me.
I'm getting "virtual cannot be specified on member function templates."
Any ideas?

I want to be able to store a vector of objects where each object is of the same base class (and can therefore be inserted into the vector), but where each object (of various derived classes) would return a different type for: getValue();

so basically, I'd like to be able to do something like the following:
vector<MyClass> myVector;
myVector.push_back(MyClassIntVersion(1));
myVector.push_back(MyClassFloatVersion(1.0));
etc.

Thanks!

Why? Because I want to be able to manage a group of objects that have similar properties but contain different types of data within one compact vector. Am I missing something?

Any thoughts? Thanks.

I'm creating an animation parameter system. An animation can have parameters of different types: float, int, etc. I'd like to store all of an object's parameters in a single vector or map and allow the object to access the value for each parameter as needed. Does that make sense?

Originally Posted by pollypocket4eva

Hi,
I'm trying to do something like the following...
I would like fill a vector with objects that are of different type variations of the same template base class.
The code below of course does not work because the vector needs a template arg. How do you get around this? A wrapper class? If so, how?
Thanks!

Code:

template <class T>
class MyClassBase {
public:
	MyClassBase() {
	}
	
	T myValue;
};

class MyClassFloat : public MyClassBase<float> {
	MyClassFloat(float myInput) {
		myValue = myInput;
	}
};

class MyClassInt : public MyClassBase<int> {
	MyClassInt(int myInput) {
		myValue = myInput;
	}
};

int main (int argc, const char * argv[])
{
    vector<MyClassBase> myVec;
    myVec.push_back(MyClassFloat(1.0));
    myVec.push_back(MyClassInt(1));
    return 0;
}

To get polymorphic behavior you're either going to have to allocate the desired derived types at runtime (with the aid of a "smart-pointer", hopefully) or else declare them on the stack and then store pointers to either (or maybe both) in your vector.