Initialize std::array with a range (pair of iterators)

Question

How can I initialize an std::array from a range (as defined by a pair of iterators)?

Something like this:

vector v;
...
// I kn         


        

Answer 1

You can use BOOST_PP_ENUM as:

include 

#define INIT(z, i, v) v[i] 

std::vector v;

//fill v with at least 5 items 

std::array a = { BOOST_PP_ENUM(5, INIT, v) };  //MAGIC

Here, the last line is expanded as:

std::array a = {v[0], v[1], v[2], v[3], v[4]}; //EXPANDED LINE

which is what you want.