Question

What is the simplest way to convert array to vector?

void test(vector<int> _array)
{
  ...
}

int x[3]={1, 2, 3};
test(x); // Syntax error.

I want to convert x from int array to vector in simplest way.

Answer 1

Use the vector constructor that takes two iterators, note that pointers are valid iterators, and use the implicit conversion from arrays to pointers:

int x[3] = {1, 2, 3};
std::vector<int> v(x, x + sizeof x / sizeof x[0]);
test(v);

or

test(std::vector<int>(x, x + sizeof x / sizeof x[0]));

where sizeof x / sizeof x[0] is obviously 3 in this context; it’s the generic way of getting the number of elements in an array. Note that x + sizeof x / sizeof x[0] points one element beyond the last element.