How to print out the contents of a vector?

Question

I want to print out the contents of a vector in C++, here is what I have:

#include 
#include 
#include 
#include         


        

Answer 1

For those that are interested: I wrote a generalized solution that takes the best of both worlds, is more generalized to any type of range and puts quotes around non-arithmetic types (desired for string-like types). Additionally, this approach should not have any ADL issues and also avoid 'surprises' (since it's added explicitly on a case-by-case basis):

template 
inline constexpr bool is_string_type_v = std::is_convertible_v;

template
struct range_out {
  range_out(T& range) : r_(range) {
  }
  T& r_;
  static_assert(!::is_string_type_v, "strings and string-like types should use operator << directly");
};

template 
std::ostream& operator<< (std::ostream& out, range_out& range) {
  constexpr bool is_string_like = is_string_type_v;
  constexpr std::string_view sep{ is_string_like ? "', '" : ", " };

  if (!range.r_.empty()) {
    out << (is_string_like ? "['" : "[");
    out << *range.r_.begin();
    for (auto it = range.r_.begin() + 1; it != range.r_.end(); ++it) {
      out << sep << *it;
    }
    out << (is_string_like ? "']" : "]");
  }
  else {
    out << "[]";
  }

  return out;
}

Now it's fairly easy to use on any range:

std::cout << range_out{ my_vector };

The string-like check leaves room for improvement. I do also have static_assert check in my solution to avoid std::basic_string<>, but I left it out here for simplicity.