How Do I define a Double Brackets/Double Iterator Operator, Similar to Vector of Vectors'?

Question

I\'m porting code that uses a very large array of floats, which may trigger malloc failures from c to c++. I asked a question about whether I should use vectors or deques a

Answer 1

There is no "double brackets" operator in C++. What you need to do is define a single [] operator and have it return a reference to another object, which can in turn respond to its own [] operator. This can be nested as many levels deep as you require.

For example, when you create a vector of vectors, the [] operator on the outer vector returns a reference to one of the inner vectors; the [] operator on that vector returns a reference to an individual element of the vector.

std::vector > example;
std::vector & first = example[0];  // the first level returns a reference to a vector
float & second = example[0][0];  // the same as first[0]