将std :: array转换为std :: vector

Question

In the code below, the size of the function (foo) argument ( std::vector ) can be anything to make the function a generic one. However, sometimes the size container is known so std::array can be used. The problem is to convert the std::array to std::vector . What is the best way to solve this problem? Is it better to just use std::vector always in this case?

#include <iostream>
#include <array>
#include <vector>

using namespace std;

// generic function: size of the container can be anything
void foo (vector<int>& vec)
{
    // do something
}

int main()
{
   array<int,3> arr; // size is known. why use std::vector?
   foo (arr); // cannot convert std::array to std::vector

   return 0;
}

Answer 1

Given that you pass in an array , foo does not seem to resize the container it gets passed in (however, it does seem to modify the elements since vec is passed non-const). It therefore does not need to know anything about the underlying container other than how to access elements.

Then, you can pass a pair of iterators (and make the iterator type a template argument), as many STL algorithms do.

Answer 2

The function accepts a vector by reference. So there is no any sense to pass an object of type std::array to the function. It could have a sense if the parameter of the function would be defined as const reference to a vector.