Getting tail of a vector?

Question

How could I go about getting the tail of a vector:

std::vector<int> Example {1,2,3,4,5};

//head = [1]
//tail = [2,3,4,5]

Python:

head = Array[0]
tail = Array[1:]

Haskell

myRecursiveFunction :: [Int] -> [Int]
myRecursiveFunction (x : xs) = x + 1 : myRecursiveFunction xs

I'm aware I could use an iterative STL algorithm, such as accumulate:

std::vector<int> Example {1,2,3,4,5};
std::accumulate(Example.begin() + 1, Example.end(), 0);

However this seems quite verbose, are there simpler solutions? I don't mind if the solution copies or views the tail, I'm just looking for a method to easily access the tail of a vector without using iterators.

Answer 1

Don't use accumulate. That doesn't even do what you want. Just use the vector constructor:

std::vector<int>( example.begin() + 1, example.end() );

This builds a new vector in memory, and copies from element 1 to the end. If you want an actual identifier for it:

std::vector<int> example_slice( example.begin() + 1, example.end() );

If you're trying to pass these around for some kind of recursive process. You might want to reconsider. Maybe we're dealing with an XY problem here.

Answer 2

If by "getting the tail of the vector" you mean removal of first element or first n elements, use vector::erase :

example.erase(example.begin());  // remove the first element

-- or --

example.erase(example.begin(), example.begin()+n);  // remove the first n elements

If by "getting the tail of the vector" you mean saving its tail to another vector, use the range constructor:

vector<int> tail(example.begin()+n, example.end());

Answer 3

The closest to Python that I can think of is std::slice:

std::valarray<int> Example {1,2,3,4,5};

auto head = Example[std::slice(0, 1, 1)];
auto tail = Example[std::slice(1, Example.size() - 1, 1)];

Not as simple as Python, but closer than your own example.