Thread: How properly get data out of vectors of templates?

How would I do this?

I want to be able to handle vectors of many different types of data and vectors that can contain any number of other vectors of data.

Currently, I have a templated function that handles vectors of vectors of <typename T> (which could be anything from int to vectors of something else). As well, I have specialized/overloaded functions to handle the single-level vectors of data (e.g. vector<string>). So the templated function only handles vectors of vectors of....whatever and then as it loops down to the last vector of data, it "passes" it off to the overloaded specialized functions.

My problem is that the way I'm currently doing this creates extra uselss objects and thus isn't clean/efficient. I can't seem to figure out how to properly narrow down the vectors.

Code:

vector<int>* convert(SomeClass obj)
{
	//Return vector
	vector<int>* retVector = new vector<int>();
	
	//Get the values
	int* values = ...elided...
	
	//Put into vector
	retVector->assign( values, values + length );
	
	//Clean up
	delete values;
	
	return retVector;
}

vector<vector<int> >* convert(SomeClass obj, vector<int> spec)
{
	//Length of array
	int length = GetArrayLength( obj );
	
	//Return vector
	vector<vector<int> >* retVector = new vector<vector<int> >();
	
	//Get all inner arrays
	for ( int i = 0; i < length; i++ ) 
	{
		//Create an inner vector
		vector<int>* innerVector;
		
		//Now get the element of the outer SomeOtherClass Array
		SomeOtherClass otherObj = ...elided...
		
		//Set data
		innerVector = convert( env, otherObj );
		
		//Add it to the outer vector
		retVector->push_back( *innerVector );
		
		//Clean up
		delete innerVector;
	}
	
	return retVector;
}

template <typename T>
vector<vector<T> >* convert(SomeClass obj, vector<T> spec)
{
	//Length of array
	int length = GetArrayLength( obj );
	
	//Return array
	vector<vector<T> >* T = new vector<vector<T> >();
	
	//Set all inner arrays
	for ( int i = 0; i < length; i++ ) 
	{
		//Create an inner vector
		vector<T>* innerVector;
		
		//use this to narrow down to eventually the specialized function
		T subSpec; 
		
		//Now get the element
		SomeOtherClass otherObj = ...elided... 
		
		//Convert inner data
		innerVector = convert( env, otherObj, subSpec );
		
		//Add it to the outer vector
		T->push_back( *innerVector );
		
		//Clean up refs
		delete innerVector;
	}
	
	return T;
}

int main()
{
	vector<vector<string> >* ret = convert( env, o2, vector<string>() );
	
	//Print out results
	for ( vector<vector<string> >::const_iterator it = ret->begin(); it != ret->end(); ++it )
	{
		vector<string> vec = *it;
		for ( vector<string>::const_iterator vecIt = vec.begin(); vecIt != vec.end(); ++ivecIt )
		{
			printf( ( ( *vecIt ) + "\n" ).c_str() );
		}
	}
}