Re: [boost] [Range] New I/O functions for ranges

-----Original Message----- From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of Indiana Sent: 05 October 2014 16:47 To: boost@lists.boost.org Subject: Re: [boost] [Range] New I/O functions for ranges

On 14-10-01 05:00 AM, Paul A. Bristow wrote:

...

You may well be right, but I'm only reporting what I found were my 'needs'.

You can show how to wrap write_all output (with 'smart' delimiter - no ugly trailing commas!) with prefix and suffix strings, that will probably be fine. Yeah, sure - actually write_all() does that right out of the box:

o << "prefix" << write_all({1,2,3}, "delimiter") << "suffix"; // Prints: "prefix1delimiter2delimiter3suffix";

So:

o << '{' << write_all({1,2,3}, ',') << '}'; // Prints: "{1,2,3}"

...

I only meant a string in C++ syntax like

int[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

that you have shown is possible. Actually, you can probably generalize that. The following code isn't tested, but:

template void format_range(std::basic_ostream& o, Range&& r) { using std::begin; using std::end; using value_type = std::decay_t;

std::basic_ostringstream oss{}; oss.imbue(std::locale::classic());

oss << boost::typeindex::type_id().pretty_name(); oss << '[' << std::distance(begin(r), end(r)) << ']' << " = "; oss << '{' << write_all(std::forward<Range>(r), ", ") << "};\n";

o << oss.str(); }

Calling format_range() for any range type should give the output you want, more or less, dependent on the range value type.

auto v = std::vector<int>{1,2,3}; cout << format_range(v); // Prints: "int[3] = {1, 2, 3};" auto const a = std::array{1.1, 2.2, 3.3, 4.4}; cout <<

format_range(a); //

Prints: "double[4] = {1.1, 2.2, 3.3, 4.4};"

Even neater :-)

...

Now you need some enthusiastic users to support you on a review ;-) Yeah? I'm not sure how the process goes here.

Nor me. I assume you've seen http://www.boost.org/development/requirements.html

Do I make a pull request on the Boost.Range repository and implement the changes? Or do I implement the idea separately, so people can experiment and mess around with it, and only after it's passed review try to integrate it with the rest of the library? Do I get in touch with the Boost.Range maintainers (seems to be Thorsten Ottosen and Neil Groves)?

I doubt if you should try to add to the existing range library - unless the Boost.Range maintainers are keen, but yes - do ask. You could produce a new-name (range_write, range_out, range_IO?) sub-module at GIThub that people can clone into their existing Boost GIT files to see if they like it? Good luck! Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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