Boost C++ Libraries: Ticket #6793: Support construction from range

Mon, 16 Apr 2012 16:36:35 GMT

Just read that constructors are not an option. How about make_array() instead?

status changed

Marshall Clow — Mon, 17 Dec 2012 17:21:00 GMT

status new → assigned

It seems to me that make_array would require either (a) returning the array by value (copying or depending on RVO), or passing in the destination array by reference (which means you have to construct it beforehand.

In either case, I don't see a compelling need, when compared to:

boost::array<T, N> arr;
std::copy ( iter1, iter2, arr.begin ());

Can you show me an example where make_array would be a significant improvement? Thanks!

Mon, 17 Dec 2012 17:31:46 GMT

That requires temp vars for both input and output.

string g() { return "Olaf"; }
void f(array<char, 20> const&);
f(make_array(g())); // desired
{
  string s = g();
  array<char, 20> a;
  std::copy(s.begin(), s.end(), a.begin());
  f(a);
}

IMO the one liner looks much better than the 6 liner and the 6 liner can't even do size checking.