On Sunday 11 January 2009, Christoph Duelli wrote:

I recently had the need to produce from a vector<uint> a string representation (like for IPs) like "23.1.4.742.234.0".

You could also use Karma (part of the Spirit 2 library) for that job. See the included example. HTH, Chris #include // for 'operator+=()' #include #include <cassert> #include <cstdlib> #include <vector> using namespace boost::assign; // bring 'operator+=()' into scope using namespace boost::spirit; using namespace boost::spirit::ascii; int main() { std::vector<int> v; v += 23, 1, 4, 742, 234, 0; std::string generated; bool success = karma::generate(std::back_inserter(generated), int_ % ".", // format description v // data ); assert(success && "23.1.4.742.234.0" == generated); return EXIT_SUCCESS; }

I recently had the need to produce from a vector<uint> a string representation (like for IPs) like "23.1.4.742.234.0".

I thought that if only those were uints were strings I could boost::join them together.

After a bit of searching the internet I found: make_view... very helpful, as indeed operating on iterators and containers only is a bit restrictive.

So, first, I'd like to express my thanks for providing such helpful libraries (I love it how Boost.Bind and ASIO fit together, e.g.!). Great job everyone!

Is there a better way to get to the string representation hinted to above? What I did is:

#include // not yet part of Boost 1.37

// Helper to convert an uint to a std::string struct Stringer { std::string operator() (unsigned u) const { return boost::lexical_caststd::string(u); } };

boost::functionstd::string(unsigned) stringer = Stringer(); // way better than writing the loop by hand! std::string s = boost::join(boost::make_view(data_, stringer), "."); // Does not compile with gcc 4.2.1 // std::string s = boost::join(boost::make_view(data_, Stringer()), ".");

Is there some existing class that makes my helper class Stringer unnecessary? (Can I use lexical_cast here w/o a helper class?) Is it possible to avoid putting the functor into a local Boost.Function variable?

The Lambda lib is powerful in creating in-place unnamed function object, isn't it? Have you ever considered it?

When will range_ex and make_view() be part of a Boost release? 1.38? (Please?)

I also have interest to know the answer. B/Rgds Max