id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
6785,read_json does not compile on GCC 4.7.0 with std=c++11,Wojciech Cierpucha <cierpuchaw@…>,Sebastian Redl,"Just as the summary says it is impossible to use read_json(...) from Boost.PropertyTree with GCC 4.7.0 with std=c++11.

The error is in json_parser_read.hpp:105 - context<PTree>::a_literal_val::operator():

{{{
c.stack.back()->push_back(std::make_pair(c.name, Str(b, e)));
}}}

Error message:
{{{
/usr/include/boost/property_tree/detail/json_parser_read.hpp:105:17: error: no matching function for call to ‘boost::property_tree::basic_ptree<std::basic_string<char>, std::basic_string<char> >::push_back(std::pair<std::basic_string<char>, std::basic_string<char> >)’
/usr/include/boost/property_tree/detail/json_parser_read.hpp:105:17: note: candidate is:
In file included from /usr/include/boost/property_tree/ptree.hpp:516:0,
                 from main.cpp:4:
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:362:9: note: boost::property_tree::basic_ptree<Key, Data, KeyCompare>::iterator boost::property_tree::basic_ptree<Key, Data, KeyCompare>::push_back(const value_type&) [with Key = std::basic_string<char>; Data = std::basic_string<char>; KeyCompare = std::less<std::basic_string<char> >; boost::property_tree::basic_ptree<Key, Data, KeyCompare>::value_type = std::pair<const std::basic_string<char>, boost::property_tree::basic_ptree<std::basic_string<char>, std::basic_string<char> > >]
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:362:9: note:   no known conversion for argument 1 from ‘std::pair<std::basic_string<char>, std::basic_string<char> >’ to ‘const value_type& {aka const std::pair<const std::basic_string<char>, boost::property_tree::basic_ptree<std::basic_string<char>, std::basic_string<char> > >&}’
}}}

It compiles successfully on 4.7.0 with -std=c++98 and on both 4.6.3 and 4.5.3 in both c++98 and c++0x modes.

It seems strange to me that it compiles at all in c++98 mode and with an older gcc version, since (according to docs) ptree::push_back wants a pair<string, ptree>. In quoted line of code it gets a pair<string, string> and ptree(string) constructor is declared explicit. I have no idea why it was permitted without an explicit conversion before.",Bugs,closed,To Be Determined,property_tree,Boost 1.49.0,Problem,fixed,ptree read_json,