Can't get (translate) literal values with suffixes out of ptree

[Ricardo Abreu <ricardolafabreu@…>]

Hello,

I just figured that the property_tree lib cannot translate some acceptable literals. Here is an example to show this:

#include <boost/property_tree/ptree.hpp>
#include <boost/optional.hpp>
#include <iostream>

using namespace boost::property_tree;
using namespace std;

void printo(boost::optional<long long> o, const std::string & name)
{
    if(o)
      cout << name << " is: " << *o << endl;
    else 
      cerr << "couldn't get " << name << endl;
}

int main()
{
  ptree p;
  p.put("good_long_long", "0");
  long long test1 = 0; // show that 0 is an acceptable long long literal
  p.put("bad_long_long", "0LL");
  long long test2 = 0LL; // show that 0LL is an acceptable long long literal
  auto good = p.get_optional<long long>("good_long_long");
  auto bad = p.get_optional<long long>("bad_long_long");
  printo(good, "good");
  printo(bad, "bad");

  return 0;
}

Apparently the stream_translator doesn't consume the 'L's and then the test iss.get() != Traits::eof(), in stream_translator.hpp, is true, resulting in an empty optional.

Please feel free to contact me. I hope not, but I'm sorry if there is something stupid I am missing.

Cheers, Ricardo Abreu

[Sebastian Redl]

The stream_translator, as it name indicates, uses an iostream (specifically, a stringstream) to convert data. It is therefore compatible with the data formats supported by iostreams. C++ language integer literal syntax is not supported by streams, and thus isn't supported by the stream_translator. If you need compatibility with such formats, you need to write your own translator.