Memory leak?

[geeare1]

Hello, I'm wondering about the best way to return objects in class functions. The code I'm posting is an overloaded + operator that adds two matrices (created with valarrays), stores the result in a new matrix and returns a pointer to the matrix containing the result.

template <class T>
Matrix<T>& Matrix<T>::operator+ (Matrix<T>& rhs){

	if((nRows_ != rhs.nRows_) || (nCols_ != rhs.nCols_))
		throw BadSize("error; both matrices must be the same size");

	Matrix<T>* result = new Matrix<T>(nRows_, nCols_);

	for(unsigned i = 0; i < nRows_; ++i)
		result->matrix_[i] = matrix_[i] + rhs.matrix_[i];

	return *result;
}

It seems to me that this creates a memory leak (is that correct?). What is the best way to do this sort of thing?

Thanks,
-gr

[jsmith]

The above function would be used in an expression of the form

a + b

where a and b are Matrix<T> objects.

That said, operator+ should not modify the value of either a or b.
Having said that, operator+ should be declared a const member function
and should take rhs by const reference.

Furthermore, operator+ should return a Matrix<T> by value, not by reference.
Having said that, it makes your problem much easier... don't dynamically
allocate a new matrix on the heap; create it on the stack. This fixes the
memory leak.

[geeare1]

jsmith,

Thanks for your help!

-gr