[Boost-bugs] [Boost C++ Libraries] #10102: dynamic_properties inconsistent usage of lexical_cast and stringstream

Subject: [Boost-bugs] [Boost C++ Libraries] #10102: dynamic_properties inconsistent usage of lexical_cast and stringstream
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-06-07 11:09:13

#10102: dynamic_properties inconsistent usage of lexical_cast and stringstream
--------------------------------------------+----------------------
 Reporter:  Sergey Mitsyn <svm at jinr.ru>  |      Owner:  jewillco
     Type:  Bugs                            |     Status:  new
Milestone:  To Be Determined                |  Component:  graph
  Version:  Boost 1.55.0                    |   Severity:  Problem
 Keywords:                                  |
--------------------------------------------+----------------------
 Hello,

 The {{{boost::dynamic_properties}}} is inconsistent with usage of
 {{{boost::lexical_cast}}} and {{{std::stringstream}}}. In file
 boost\property_map\dynamic_property_map.hpp, the function

 {{{
 template<typename Value>
   inline Value read_value(const std::string& value)
   }}}

 uses {{{boost::lexical_cast}}}, while

 {{{
 std::string dynamic_property_map_adaptor::get_string(const any& key)
 }}}

 uses {{{std::stringstream}}}.

 It is a problem, for example, if used together with a BGL's
 {{{boost::write_graphvis_dp}}} and {{{boost::read_graphvis}}} if {{{NaN}}}
 attribute values are written and read. With {{{std::stringstream}}} on my
 machine (Windows 7 + MSVC 12), NaN's are written as {{{"1.#QNAN"}}}, and
 lexical_cast produces and consumes {{{nan}}} and {{{NAN}}} [1]. In such
 case {{{boost::bad_lexical_cast}}} is thrown whenever read_graphvis is
 called for graphviz file containing {{{NaN}}}s.

 Modifying {{{dynamic_property_map_adaptor::get_string}}} to use
 boost::lexical_cast seems to fix the issue with graph reading/writing.
 Though I'm not trying to use such files as an input for graphviz.

 Speaking about graphviz, docs seem not to define any restrictions on
 attribute values, and I haven't looked at the source code. Quick googling
 gave me [http:/_/comments.gmane.org/gmane.comp.video.graphviz/7062], which
 is not related to this case, but it is stated there that graphviz uses
 {{{atof()}}}, which is locale-dependent and feels messy.

 [1] see boost/lexical_cast.hpp, function
 {{{
 template <class CharT, class T>
 bool parse_inf_nan(const CharT* begin, const CharT* end, T& value)
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10102>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.